Covid-19: A Complete Reference Guide for Indians

Last modified on January 2022
With inputs from Dr. Sreelekha Daruvuri

The novel coronavirus has wreaked havoc in people’s lives, especially the health of children and the elderly. It has exacerbated the already pre-existing health crisis in India.
Experts cite low allocation of resources and lack of political will as reasons that have brought the public healthcare system on its knees.
Scenes of hospital beds running out of beds and life-saving oxygen cylinders have hogged international headlines. The impact of Covid-19 in our day-to-day lives is unprecedented; it has disrupted our economy, health and society, and their impact on us is likely to be long-lasting.

Current Covid Situation in India

  • Spike in positive cases due to Omicron 
  • Covaxin for kids aged 15-18 years has been permitted from Jan 3rd, 2022
  • Precaution/booster dose is starting with the front line workers and Adults aged 60 or above with comorbidities from  Jan 10th, 2022

63.26 Crore + Indian Citizens Vaccinated (71.29% fully vaccinated) as of Jan 10th, 2022. Source: 

RT PCR at Home

Last modified on January 2022
With inputs from Dr. Sreelekha Daruvuri

The novel coronavirus has wreaked havoc in people’s lives, especially the health of children and the elderly. It has exacerbated the already pre-existing health crisis in India.
Experts cite low allocation of resources and lack of political will as reasons that have brought the public healthcare system on its knees.
Scenes of hospital beds running out of beds and life-saving oxygen cylinders have hogged international headlines. The impact of Covid-19 in our day-to-day lives is unprecedented; it has disrupted our economy, health and society, and their impact on us is likely to be long-lasting.

Current Covid Situation in India

  • Spike in positive cases due to Omicron 
  • Covaxin for kids aged 15-18 years has been permitted from Jan 3rd, 2022
  • Precaution/booster dose is starting with the front line workers and Adults aged 60 or above with comorbidities from  Jan 10th, 2022

63.26 Crore + Indian Citizens Vaccinated (71.29% fully vaccinated) as of Jan 10th, 2022. Source: 

RT PCR at Home


In late December 2019, a mysterious outbreak of pneumonia, characterized by fever, dry cough, fatigue and diarrhoea, engulfed the wholesale wet market of Wuhan, China. Wet markets are live animal market places that sell fresh meat, fish, and other animal products.

About 66% of the staff in the market were infected, and several people died. A panic ensued, and the local health authorities soon shut the market down. But, by then, it was too late; the infection not only spread to other provinces across China but had also spread across Europe, North America and some Asian countries.

The new strain of coronavirus was called the novel coronavirus (SARS-VoV-2), and it causes the disease Covid-19.
This new strain of coronavirus led to several deaths across the globe, and the outbreak was soon announced as a pandemic.

Chapter 2: Timeline Of Covid-19

Let’s take you through some important dates and timeline of the pandemic,

Date Event
Late December 2019  Mysterious outbreak of pneumonia, Wuhan, China.
January 1, 2020 The local health authorities shut down the wet market in China.
January 27, 2020 India reported the first case of a novel coronavirus in Thrissur, Kerala.
January 30, 2020 The WHO declared a Public Health Emergency of International Concern (PHEIC).
February 6, 2020 The infection had spread over to 25 countries; 28, 276 people were infected with this mysterious disease, and 565 deaths were documented by the World Health Organization (WHO). Most of these infected people had a travel history to Wuhan, China.
March 11, 2020 The World Health Organization (WHO) officially announced the outbreak as a pandemic. More than 118000 cases had been reported in 114 countries, and 42911 deaths were recorded.
December 18, 2020 SARS-Cov-2 Alpha variant, United Kingdom.
December 18, 2020 SARS-Cov-2 Beta variant, South Africa.
January 11, 2021 SARS-Cov-2 Gamma variant, Brazil.
May 11, 2021 SARS-Cov-2 Delta variant, India.
November 26, 2021 SARS-CoV-2 Omicron variant, Variant of concern, Multiple countries.

Chapter 3: History Of Coronaviruses (1920 - 2021)

Coronaviruses are a group of RNA viruses that cause diseases in birds, animals, and humans. They have existed for many decades. The earliest report of coronavirus infection in animals first occurred in the late 1920s.

There are many different species of coronaviruses, and they are classified under any one of the following four Genera. **(They are not to be confused with alpha, beta, delta and gamma variants of Covid-19)**

  1. Alpha coronaviruses
  2. Beta coronaviruses
  3. Delta coronaviruses and
  4. Gamma coronaviruses

Things you Need to Know

  • Alpha and Beta coronaviruses cause diseases in humans.
  • The Alpha and Beta are derived from the bat gene pool, meaning the disease originated primarily from the bats.
  • Gamma and Delta coronaviruses come from the avian and pig gene pool; they primarily infect chickens, certain birds and pigs.
  • The group of coronaviruses that infect humans are called human coronaviruses (HCoV).

As of date, there are seven coronaviruses that cause diseases in humans. They are listed below under the following two Genera:

Alpha Coronaviruses

  • HCoV-229E was discovered in the mid-1960s (HCoV stands for Human Coronavirus).
  • HCoV-NL63 was discovered in 2003 in a lab in Netherland (NL stands for Netherland).

Beta Coronaviruses

  • HCoV-OC43 was discovered in 1967 in Maryland, United States.
  • HCoV-HKU1 was discovered in 2005 in a lab in Hong Kong (HK for Hong Kong).
  • SARS CoV was discovered in 2002/2003 in Guangdong Province, China. This virus is transmitted from bats to civets to humans and causes Severe Acute Respiratory Syndrome (SARS). It has a fatality rate of 9.6%, meaning out of every 100 people infected, roughly about 9-10 people would die.
  • SARS-CoV-2 also called the novel coronavirus, first originated in Wuhan, China, in late December 2019. The virus’s origin is unknown; however, it’s thought to have been transmitted from bats to humans and causes Coronavirus Disease 2019 (Covid-19). It has a low fatality rate of 2-3% (data as of March 2020).
  • MERS-CoV was discovered in 2012 in Saudi Arabia. It’s transmitted from camels to humans. It has a very high fatality rate of about 34.4%.

Chapter 4: Covid-19: What Is The Novel Coronavirus?

The Covid-19 is an infectious disease caused by SARS-CoV-2, also called the novel coronavirus. It’s a beta coronavirus (Order: Nidoviridae, Family: Coronaviridae, Genus: Coronavirus), very similar to SARS coronavirus, i.e., they cause similar illnesses in humans but with varying virulence (or severity); SARS has a higher virulence (fatality rate of about 9.6%) compared to Covid-19 (fatality rate of about 2-3%). Covid-19, like SARS, causes respiratory and gastrointestinal tract infections.

  • Upper respiratory tract infections include the common cold, pneumonia, or acute respiratory distress syndrome (ARDS).
  • GI tract infections are characterized by diarrhoea and stomach upsets.

Mode of Transmission of SARS-CoV-2

The transmission mode of the virus is through respiratory droplets and the faecal route, sometimes through a faulty drainage system too. The virus can survive on a surface for up to 24 hours and airborne for about three hours.

The entry points of the virus are through the mucous membranes present in the eyes, nose and mouth. When a person touches an infected object with the virus on them and then touches their mouth, nose or eyes, they could be infected.

Incubation Period of the Virus

You don’t become sick immediately after contracting the virus. That’s because the virus needs time to increase its numbers to cause disease. i.e., their numbers need to cross a specific threshold value, below which they wouldn’t be able to cause any disease.

The incubation period is defined as the time between first contracting the virus and the onset of symptoms. The incubation period for the novel coronavirus is between 2 and 14 days.


The diagnosis of Covid-19 involves a simple swab test. The sample is usually taken from the nose (nasopharyngeal swab), throat (throat swab) or saliva. The sample is then sent to an accredited lab for testing.

In the case of rapid antigen testing, the results are available almost immediately. But in the case of Reverse Transcription Polymerase Chain Reaction (RT-PCR), the sample is sent to an accredited lab, and the results are made available in 72 hours.
RT-PCR is a more reliable diagnostic test for Covid-19. The technique involves generating millions of copies of an initially small segment of Covid RNA using the PCR machine.


Treatment for Covid-19 involves self-care:

  • Self-quarantine in a well-ventilated room.
  • Use a mask; discard the mask after 8 hours of use.
  • Drink sufficient fluids to keep yourself well hydrated.
  • Follow respiratory etiquette.
  • Wash your hands frequently with soap.
  • Monitor temperature and oxygen levels.

Severe cases of Covid-19 require immediate medical attention. If you have trouble breathing, get in touch with your doctor immediately.


Preventive methods reduce the chances of getting infected with Covid-19.

Staying home, wearing a mask in public, washing your hands with soap and water, using hand sanitizers, practising good respiratory hygiene, and avoiding touching eyes, nose, and mouth without cleaning them are some excellent preventive measures.

Get Vaccinated

  • The vaccine is intended to develop immunity against the SARS-CoV-2, which causes Covid-19.
  • Vaccination may not make you immune to Covid-19 infection, but they are more likely to reduce the severity and fatality of the disease.
  • Get vaccinated as soon as it’s your turn. This way, you ensure your safety and also the safety of others.

Wear a Mask
When and how to wear masks

  • Sanitize your hands or wash them at least for 20 seconds before putting on a mask.
  • Put on the mask. The mask should sufficiently cover your mouth, nose and chin. Touch only the bands while putting on the mask.
  • When you take off the mask, make sure not to touch your mouth, eyes or nose.
  • Dispose the mask if it’s a medical mask in a closed bin, else wash it if it’s a fabric mask.
  • Make wearing a mask around people a norm. Encourage others to wear a mask.

How to wear a mask

Practice Social Distancing

The risk of spreading the infection in crowded places or places with insufficient ventilation is higher. Outbreaks have often been reported in places where people gather in large numbers, often in crowded indoor settings such as restaurants, bars, festivals, and places of worship. To make your environment safer,

  • Avoid places that are crowded, closed or involve close contact.
  • If you have to meet people for work, meet them outside. Outdoor settings are relatively safer than indoor settings.
  • But if you have to meet them in an indoor setting, take necessary precautions such as
    • Wearing a mask.
    • Opening windows or doors for proper airflow and ventilation.
    • Washing or sanitizing your hands.

Keep Good Hygiene

  • Following are some ways to keep good hygiene,
  • Wash your hands regularly with soap and water.
  • Apply the soap all over your hands and wrists.
  • Lather and rub your hands vigorously, adequately scrubbing all surfaces of
  • your hands, fingers, nails and spaces between your fingers and thumbs.
  • Scrub your hands and wrists at least for twenty seconds.
  • Please wash your hands with water and dry them using a clean towel.

How to wash your hands

COVID in India: Home Care

All the care you need at the safety of your home!

Chapter 5: The Omicron Variant

The Omicron variant is another variant of Concern (VOC) declared by the WHO on November 26, 2021. It first emerged in South Africa. The Omicron variant is believed to be even more contagious than the Delta variant, i.e., they have a higher transmissibility rate.

  • The Omicron variant has about 30 mutations in their Spike proteins compared to the Delta variant, which has about 9. As a result, they may have a greater binding capacity to ACE2 receptors present in the alveoli cells, leading to an increased entry of viruses into cells compared to the Delta variant.
  • Higher binding capacity to ACE2 receptors in alveoli cells means a higher replication rate and viral load of the Omicron variant than the Delta variant.
  • Further, higher mutations in the S-protein could mean lower antigen-antibody immune response caused by the vaccine. i.e., decreased efficacy of the vaccine.
  • Decreased efficacy of the vaccine could lead to more severe symptoms in patients. i.e., higher hospitalization rates, ICUs and deaths.
  • Further, the Reproduction Rate, Ro of the Omicron variant, is higher which means a single person can infect at least six other people.
  • These figures are very evident, considering the recent events in South Africa. The Omicron variant has only taken a few weeks to spread compared to the Delta variant, which took a couple of months.

7 Steps To Beat Omicron

Who is more prone to be infected by the Omicron variant?

As of now, due to limited data, it’s uncertain which group of people are at a greater risk. But, given, it has a higher Ro value and S-protein mutations, it means this variant can have a higher transmissibility rate, severity (hospitalizations and death) and decreased vaccine efficacy than the Delta variant.

Symptoms of the Omicron variant Virus

The symptoms of the Omicron variants are very similar to that of the other variants. But it could differ from the other variants in its severity, i.e., hospitalizations, ICU care & ventilators and deaths.

Read more about the Omicron variant.

Chapter 6: The Delta Variant

Delta Variant is one of the Viruses of Concern (VOC) designated by the World Health Organization (WHO). These are called VOC because they have a higher rate of transmissibility and virulence (severity). The earliest documented samples of the Delta variant were first observed in India in October 2020. It was then designated a Variant of Interest (VOI) on April 4, 2021, and Variant of Concern (VOC) on May 11, 2021.

COVID-19 Delta And Delta Plus Variant: What We Know So Far. The Delta variants have a mutation in their Spike proteins (S-proteins), which increases their ability to enter the lung cells and cause infection.

  • Genetic mutation in the S-protein increases the binding capacity to ACE2 receptors present in the alveoli cells. As a result, there is an increased entry of viruses into the cells.
  • The sooner the virus can enter the cells, the easier it is to take over the cellular machinery. As a result, there is an increase in the viral load and the viral replication rate.
  • The mutation also causes antibodies to bind less effectively to S-protein, decreasing vaccine efficacy.

What are the Effects of Genetic Mutation?

The genetic mutation causes,

  • An increase in the transmissibility rate. i.e., mathematically speaking, a person infected with the original strain can infect up to 2.5 other people, but a person infected with the Delta variant can infect up to 3.5 – 4 other people.
  • An increase in the viral load. The Delta variant has almost thousand times more viral load than the Alpha variant.
  • An increase in the severity of the illness due to Covid-19. A person is up to 2.5 times at a higher risk of being hospitalized due to severe complications.

Who is more prone to be Infected by the Delta variant?

  • Unvaccinated people less than the age of 50 are more likely to be infected with the Delta variant than vaccinated people.
  • People with comorbid conditions are more likely to be severely affected with the Delta variant, irrespective of vaccination status. Therefore proper precautionary measures should be taken to avoid being infected with the virus.

Symptoms of the Delta Variant Virus

The symptoms of the Delta variant includes,

  • Fever
  • Dry cough
  • Tiredness
  • Body pain
  • Loss of taste and smell
  • Red eyes or conjunctivitis
  • Headache
  • Sore throat
  • Rashes

delta vs omicron


Chapter 7: The Black Fungus

Black fungus or Mucormycosis is not a common disease, yet it’s surging in the Covid-19 pandemic. As of date, there are over 9000 cases of Mucormycosis in India as against 20 cases a year before the pandemic. Mucormycosis usually attacks people with lower or compromised immune systems.

Covid-19 treatments and the use of steroids can compromise the patient’s immune system. When patients have to stay for a prolonged time in the hospital due to Covid-19 infection, the oxygen in the mechanical ventilator, high iron content, lack of oxygen, and unhygienic conditions can become ideal for the opportunist fungus to thrive.

Mucormycosis is a rare opportunistic fungal infection that affects nasal sinuses, oral cavities, and the brain in rare cases. It has a fatality rate of 54%.

What causes Mucormycosis?

It is caused by fungal spores inhaled by immunocompromised individuals. These fungal spores are found everywhere, in the soil, damp environments, on fruits and vegetables.

Who is vulnerable to Mucormycosis?

People with compromised immune systems, i.e.,

  • People with diabetes
  • Cancer patients undergoing chemotherapy
  • Patients on steroids or immunosuppressants.

What are the Symptoms of Black Fungus Infection?

The black fungus affects sinuses localized to the eyes, nose and dental areas. Some of its symptoms are,

  • Blackening discolouration over the nose
  • Nasal block
  • Face pain
  • Dental pain
  • Breathing difficulties
  • Coughing black sputum

Prevention of Mucormycosis

The prevention of the Black Fungus infection involves preventive measures, such as wearing masks, washing hands regularly, controlling blood sugar levels etc.

Chapter 8: Effect Of Covid-19 On Human Physiology

Respiratory Tract

The SARS-CoV-2 virus attacks the alveoli present in the lungs. They are tiny balloon-shaped sacs where the exchange of gases takes place., i.e., their job is to move oxygen and carbon dioxide into and out of your bloodstream.

Now the virus doesn’t have any resources at its disposal to reproduce. So it smartly hijacks your body’s cellular machinery to generate multiple copies of itself and, in the process, destroys the alveoli cells. Alveolar collapse can lead to hypoxemia. It’s a condition where your blood oxygen levels drop drastically, resulting in shortness of breath and difficulty breathing.

Cardiovascular System

The inflammation of the lungs could also lead to septic shock. Septic shock damages the blood vessels and causes internal bleeding. The condition is characterized by decreased cardiac output, low blood pressure and decreased supply of oxygenated blood to vital organs resulting in multisystem organ failure and the death of the individual.

Nervous System

As a result of the infection, your body generates an immune response by increasingWBCs, macrophages and cytokines (IL 2 & IL 6).

These cytokines then affect the hypothalamus. The hypothalamus is the part of your brain that controls body temperature. As a result, your temperature rises. Further, to tackle the low blood pressure, the Sympathetic Nervous System (SNS) signals the heart to beat even faster, causing an increase in the heart and respiration rates.


As the cardiac output decreases, the supply of oxygenated blood to the kidneys is reduced, causing them to malfunction. Their ability to remove creatinine and blood nitrogen is hampered, resulting in abnormalities in blood creatinine and Blood Urea Nitrogen (BUN) levels.


Similarly, decreased cardiac output damages the liver, resulting in abnormalities in ALT, AST, Bilirubin, and acute-phase reactive proteins levels. Also, this virus can directly cause liver damage.

Gastrointestinal Tract

The primary way the virus hijacks the body’s cellular machinery is by binding to a specific receptor in the cell called the Angiotensin-Converting Enzyme 2 (ACE2). It’s a protein found in abundance in gastric, duodenal and small intestine’s glandular cells. These proteins provide the entry point for the coronavirus to hook into and infect the cells. As a result, the patient may experience diarrhoea, nausea, and vomiting symptoms.

For more on long term health complications, signs and symptoms, click here.

Chapter 9: Who Is At Risk: Comorbidity And Long Term Effects Of Covid-19

Things you Need to Know

  • People of any age with the illness listed below are more likely to get severely ill with Covid-19.
  • Vaccination and preventive measures are crucial, especially if you are elderly or have multiple health issues listed below.
  • The list mentioned below isn’t exhaustive. If you have a condition not mentioned here, kindly consult your doctor on protecting yourself from Covid-19.


People of any age with the illness listed below are more likely to develop a severe illness with Covid-19. Severe illness means a person may be

  • Hospitalized.
  • Require a ventilator or Intensive Care Unit or
  • May face death.


  • Older adults over 65 are more likely to get severely ill from Covid-19 than others. The fatality rate among them is 81%. The number of deaths among them is 80 times higher than the people in 18-29 age groups.
  • The risk of severity of the illness increases with an increase in the underlying health conditions in a person.
  • A person with disabilities is more likely than those without disabilities to develop severe cases of Covid-19 health complications.

Covid-19 vaccines and preventive measures are necessary if you are above 65 or have an underlying health condition.

Medical Conditions


Cancer patients have a higher risk of severe illness from Covid-19. Cancer weakens the immune system. Additionally, people with blood cancer are more likely to have prolonged infection or a higher fatality rate than solid cancers.

Should a cancer patient take the vaccine?

If you had treatment for cancer such as chemotherapy, stem cell therapy, or bone marrow transplant, your doctor would primarily advise you to wait until your immune system has recovered. Or they may ask you to wait a few weeks after vaccination to get immunosuppressive treatment. Kindly consult your doctor for more information.

Chronic Kidney Disease

People on dialysis are at a higher risk of severe illness from Covid-19. They may have weakened immune systems due to the disease, making it hard for them to fight off infections. It’s also crucial to continue your dialysis as scheduled; you may have to take necessary precautions such as having your RT PCR test results in hand to avail of the services in the hospital.

Additionally, you may also have to maintain good respiratory hygiene, such as wearing a mask and washing hands frequently to reduce your chances of infection.

If you’ve had a kidney transplant and are on immunosuppressive drugs, kindly consult your doctor on the vaccination process.

Chronic Liver Disease

Alcohol-related liver disease, fatty liver disease, scarring of the liver, autoimmune hepatitis puts you at a higher risk of severe illness from Covid-19. Severe infection of Covid-19 can cause multi-organ failure, including the liver.

Chronic Lung Disease

Asthma, pulmonary embolism, pulmonary hypertension, bronchiectasis, bronchopulmonary dysplasia, chronic bronchitis, and cystic fibrosis are some chronic lung diseases that put you at a higher risk of severe illness from Covid-19. Following are some crucial tips you need to consider if you have a lung disease,

  • Get vaccinated, not just for Covid-19 but also for flu and pneumonia.
  • Get tested and treated if you are infected with the virus.
  • Put on a mask, maintain social distance and practise good hygiene.
  • Do not stop taking medications, whether inhaled or oral, unless directed otherwise by your doctor.
  • Cross verify any health information you receive on your phone or social media. Misinformation is everywhere. If you have any questions, speak with your doctor to clarify your doubts.

Neurological & Mental Health Conditions

Neurological and mental health conditions do not increase the risk of Covid-19 severity. For example, Alzheimer’s and dementia do not increase the risk for flu, but their behaviour may. They may forget to wash their hands or maintain good respiratory hygiene. Therefore, caregivers must consider the risks and take additional safety measures for people with mental illness.

Additionally, Covid-19 may worsen the cognitive impairments and symptoms of people living with dementia.

Getting vaccinated, both you and them, is a great way to protect the health of people with mental illness. But vaccinated people still can get infected with Covid-19. Therefore additional safety measures in the form of Personal Protective Equipment (PPE), frequent testing and treatment is recommended to ensure safety for everyone involved.

Things to remember,

  • For people with dementia, increased confusion is always the first symptom of any illness. If they exhibit a sudden change of behaviour, contact your doctor immediately.
  • They may need extra care and written reminders to keep good hygiene.
  • When visiting people with mental illness in the hospital, it’s essential to familiarise yourself with the safety requirements of the hospital in advance. Many hospitals are curbing visitation hours to prevent the spread of infection; therefore, knowing what is appropriate beforehand helps. Wear a mask always, maintain good hygiene, and avoid going to other places in the hospital.


People living with diabetes are more likely to develop severe symptoms of Covid-19. Additionally, having other health conditions such as hypertension or heart disease increases their risk of being severely affected with Covid-19.

With Covid-19 being new, we do not have sufficient data yet to understand if the risks of Covid-19 are different for people with Type 1 and Type 2 diabetes. However, based on the Centre for Disease Control and Prevention (CDC) data, people with Type 1 or gestational diabetes might be at a higher risk comparatively.

Heart Disease

Heart patients with coronary artery disease, hypertension and low blood pressure are at a higher risk of severe illness from Covid-19. Low cardiac output can cause multiple organ failures.

HIV Infection

People with HIV usually have many questions about Covid-19 risk and vaccine safety. It’s generally safer to get vaccinated if you don’t have any allergic reaction to any of the vaccine’s ingredients.

Further, even though you may be fully vaccinated, it doesn’t prevent you from being infected. Therefore you must continue to take all necessary precautions, such as good respiratory hygiene, washing hands, and social distancing. For more information, kindly speak with your doctor.


Being overweight adds to your risk of developing severe Covid-19 complications. Obesity is linked to decreased immunity, and it decreases your lung capacity. With an increase in Body Mass Index (BMI), you are at a higher risk of hospitalization and ICU admission associated with Covid-19 infection.

According to a report by CDC, obese children below the age of 18 are 3.07 times at higher risk of hospitalization and 1.42 times at higher risk of ending up in an ICU when hospitalized.


Pregnancy causes changes in the body, making you prone to getting sick often. Although the overall risk is low, studies suggest that pregnant women were more likely to be severely affected by Covid-19 than non-pregnant people. They are also at risk of premature delivery and other pregnancy-related complications.

Should I take the vaccine if I’m pregnant?

The covid-19 vaccine is safe to take and is recommended even if you are pregnant, breastfeeding or trying to get pregnant or might become pregnant in the future. Getting vaccinated fully reduces your chances of severe illness, hospitalizations and other complications caused by Covid-19. Further, getting vaccinated fully also increases your chances of protection from new variants and spreading it on to your baby.

To read more about how pregnant women can stay safe during pregnancy, click here.


Thalassemia is a haemoglobin disorder. The effect of Covid-19 on the disease is still being studied. However, it’s been observed that thalassemia or sickle cell anaemia does increase your risk of Covid-19 complications.

Substance Use

Substance abuse and smoking can damage your liver and lungs. Further smoking has been associated with cancer, hypertension and strokes. Also, you are at a higher risk of being infected in a bar or when you blackout with excessive consumption of alcohol.


Strokes are another comorbid health condition one should take into consideration. Like the diseases mentioned above, people with cerebrovascular are more likely to get severely ill due to Covid-19.


Tuberculosis, both pulmonary and extrapulmonary, can increase the severity of Covid-19. You should consider taking your medicines as prescribed by the doctor and consider getting vaccinated fully.

Chapter 10: Why Does Covid-19 Spread So Rapidly And Not Sars, Mers And Influenza?

Even though they have a similar gene pool, SARS, MERS and Covid-19 differ in their Reproductive Ratio, designated as R0 (R nought). It simply means the degree of spreadability of the infection, i.e., how many people can one person infect.

Let’s say, if the Reproductive Ratio of an infectious disease is 3, it means that one person can infect three other people. Similarly, if the Reproductive Ratio is 4, that person can infect four other people, and the result would be an exponential rise in the number of cases, i.e., from 1 to 4 to 16 to 31 to 65,536 and so on. But, if the Reproductive Ratio is less than 1, then that person, at least mathematically speaking, cannot infect anyone. It means the disease is hardly contagious.

Now, the Reproductive Ratio of the Covid-19 alpha variant is between 2.5 and 3, and that of MERS is between 0.3 and 0.8. Therefore, it’s much easier for Covid-19 to spread than it is for MERS.

Also, if Ro >1, the pandemic will grow, and if Ro <1, the pandemic will reverse. i.e., the only way to kill the virus is by bringing its R0 value to less than 1. But that can only happen if we can prevent the spread of infections. And hence the worldwide logic behind the quarantine.

The R0 value of SARS, at its peak, was 3. It was a highly contagious disease then. But now, the scientists, health care providers and the government have managed to bring its value down to less than 1 (i.e., 0.7). As a result, as of July 2003, the SARS virus stands eliminated from the human population.

How was it possible to eliminate SARS and not Covid-19?

Unlike Covid-19, the symptoms of SARS are very severe and almost always symptomatic. Therefore, it was easier for the health departments to track down and quarantine the infected person. As a result, they could decrease the Reproductive Ratio from 3 to 0.7. But, in Covid-19, in a large number of cases, we don’t really know who is infected and who isn’t. Therefore, it’s more challenging to trace someone who is infected.

Similarly, the Reproductive Ratio of Influenza is 1.3, meaning it has a linear growth and therefore isn’t as infectious.

Chapter 11: Genetic Mutations, Covid-19 And Its Variants

A genetic mutation is a change in the DNA/RNA sequence of any organism, bird, animal, or human being. Nature allows mutations to occur as they increase an organism’s chance of survival and reproduction. For example, Africans have a darker complexion than Europeans due to genetic mutations that happened several thousand years ago. The melanin, responsible for dark complexion, has allowed Africans to better adapt to sweltering weather conditions.

On the other hand, Europeans are better suited for cold climates, and hence they have a lighter skin colour.

A genetic mutation can happen as a result of the following:

  • RNA/DNA copying mistakes during cell division.
  • Due to exposure to mutagens (i.e., chemicals).
  • Due to exposure to ionizing radiation or
  • Infection by viruses.

Genetic mutations in viruses usually happen when they transmit from one host to another. i.e., the higher the infection rate, the higher the mutations. Mutations allow viruses to acquire new abilities to bind to host cells more efficiently and increase their chances of survival and reproduction.

As of date (December 9, 2021), there are two SARS-CoV-2 Variants of Concern (VOC):

  1. Omicron variant and
  2. Delta variant

The variants which were designated as Variants of Concern before are categorised into Variants Being Monitored.

Genetic mutations in ancestral SARS-CoV-2 has resulted in higher viral load, increased transmissibility and more severity of the disease. For example, the Delta variant has a higher transmissibility rate than the ancestral SARS-CoV-2. The Omicron variant can have a 64% higher transmissibility rate, 1000 times more viral load, and 2.5 times more severity (hospitalization rate) than the Delta variant.

Chapter 12: Vaccination Drive In India

India began administering the Covid-19 vaccines on January 16, 2021. As of January 2022, as per the Ministry of Health and Family Welfare data, over 63.26 Crore + people were vaccinated (71% fully vaccinated).

  • Age 45+: 35,09,11,890 Vaccinated
  • Age 18-44: 58,90,74,743 Vaccinated
  • Age 15-17: 2,54,92,003 Vaccinated

Data as per doses:

  • Dose 1: 88,72,76,809
  • Dose 2: 63,25,65,081
  • Precaution Booster Dose: 5,714

Vaccines Approved in India

The Government of India initially approved Covishield and Covaxin. Since September 2021, the Government has also approved the use of Sputnik V. From Jan 3rd, 2022 Covaxin for kids aged 15-18 years have been started and from Jan 10th, 2022 precaution/booster dose has started with the front line workers and adults aged 60 or above with comorbidities.

The Covishield

The Oxford AstraZeneca Covid-19 vaccine, by Serum Institute of India (SII), is sold under the brand name Covishield.

The vaccine was first developed in the United Kingdom by Oxford University and a Swedish company called AstraZeneca. It’s a viral vector vaccine and has an efficacy rate of 81% against the Alpha variant and 61% against the Delta variant.

The Covaxin

The Covaxin vaccine is developed locally by Bharat Biotech, collaborating with the Indian Council of Medical Research (ICMR) and the National Institute of Virology. It is an inactivated virus-based vaccine and has an efficacy rate of 65% against the Delta variant.

Booster Shots

The purview of booster shots and the benefit they provide is under study. The Government’s current priority is to administer two doses of the vaccine to every adult in the country. Booster shots have started from Jan 10th, 2022 for frontline workers and adults aged 60 or above with comorbidities.

Children’s Vaccine

  • Children born in 2007 or after as of Jan 3, 2022, are eligible for the first dose of vaccine.
  • Appointment for the same can be taken online or onsite (walk-in). Please note only Covaxin will be administered (as Emergency Use Listing (EUL) authorization has been granted only to Covaxin by the World Health Organization). Know more.

Chapter 13: Support For Covid-19 In India

The Covid-19 continues to transform our lives in unprecedented ways. Let’s look at some ways to find support for Covid-19.

Information on Covid-19

You can visit the Ministry of Health and Family Welfare website for information, resources, and data related to Covid-19. You’d find information on

  • Statistics: Number of active cases, discharged numbers, deaths, vaccinations.
  • Latest updates on SARS-CoV-2 variant-Omicron.
  • Covid-19 state-wise information.
  • Covid-19 facilities in States and Union Territories.

Helpline Numbers and contact details

  • Government of India toll-free helpline number: 1075 and 011-23978046.
  • You could also reach out at,,
  • You could also follow them on social media,
    • Facebook: @MoHFWIndia
    • Twitter: @MoHFW_INDIA
    • YouTube: mohfwindia

Important Government Updates and Notifications

For the following important updates and notifications, please visit

  • Guidelines for international travels.
  • List of countries where travellers would need to follow additional measures on arrival in India, including post-arrival testing (Countries at-risk).
  • Algorithm: Guidelines for International Arrivals (Dated November 30 2021).

Vaccination Centre and Slots

You can also avail of all information related to vaccination at

  • Vaccine Registration.
  • About the vaccine.
  • Before and after expectations of vaccination.

Additionally, you could also book a slot for vaccination on Whatsapp by texting “Book Slot” to the government registered number +919013353535.

Chapter 14: Covid-19 Mythbusters: Protecting You From Covid-19 Misinformation

Can the Covid-19 virus survive in humid climates?

Yes, the Covid-19 can survive in hot, humid climates. They have, in fact, spread to cold and dry countries as well.

Does drinking alcohol prevent Covid-19 infection?

Drinking alcohol does not prevent Covid-19 infection. In fact, frequent and excessive alcohol consumption can increase your risk of health problems.

Does the 5G mobile network spread coronavirus?

Viruses cannot travel on radio waves or mobile networks. In fact, viruses have travelled to countries without a 5G network. Viruses can spread through respiratory droplets when one sneezes, coughs, or speaks.

Does being able to hold my breath for more than ten seconds mean I’m not infected?

Holding your breath for ten seconds doesn’t tell you anything about Covid-19 infection. The best way to confirm if you have an infection is by getting a laboratory swab test done.

Can mosquitoes spread Covid-19 infection?

Mosquitoes do not spread Covid-19 infection.

Are antibiotics effective against Covid-19?

Antibiotics are effective only against bacterial infection and not viral infections. Your doctor may have prescribed an antibiotic when you were infected with Covid to safeguard against pneumonia caused by the bacteria Streptococcus pneumoniae.

Do Covid-19 vaccines contain pig fat/pork gelatin?

Vaccines produced in India do not contain pig fat/pork gelatin.

Will the mRNA vaccine alter my DNA?

No, vaccines can’t alter your DNA.

Will the Covid-19 cause sterilization in women?

Vaccines do not cause sterilization in anyone.

Does eating garlic prevent the infection of coronaviruses?

Even though garlic is a healthy food with antibacterial properties, there’s no evidence that it protects you from Covid-19 infections.

Chapter 15: Frequently Asked Questions

How does covid-19 spread?

The covid-19 infection spreads through respiratory droplets or aerosols when you sneeze, cough or talk. While larger respiratory droplets fall immediately to the ground, aerosols are suspended in the air for a while. Therefore, it’s recommended that you always put on a mask, especially if you are in a closed room setting.

Why is it called covid-19?

The virus SARS-CoV-2 causes the disease “Coronavirus Disease”. Hence the name Covid-19. The suffix 19 designates the year it was discovered.

What is an asymptomatic case of COVID-19?

Those who exhibit no symptoms of Covid-19 such as dry cough, fever, diarrhoea, or breathing difficulties are asymptomatic.

What is the incubation period of Covid-19?

The incubation period is the time between being infected with the virus and exhibiting the first symptoms of the disease. The incubation period of Covid-19 is between 2 and 14 days.

How to control the transmission of Covid-19?

Reproductive Ratio, designated as R0 (R nought) if >1, the pandemic will grow and if Ro <1, the pandemic will reverse. And that can only happen if we can prevent the spread of infections through vaccination, maintaining good hygiene, wearing masks and social distancing.

When to seek emergency medical attention?

If you experience severe symptoms of breathlessness, fever, headache and mental confusion you need to seek medical attention immediately.

What is the difference between covid-19 and flu?

Covid-19 and flu can exhibit similar symptoms of cold, breathlessness, fever, cough and headaches. While Covid-19 is caused by the virus SARS-CoV-2, Flu is caused by the human influenza viruses. Additionally, the gene pool of SARS-CoV-2 is from bats (mammals), and the gene pool of flu are from birds (avian).

Is coronavirus (SARS-CoV-2) different from SARS?

Both SARS and Covid-19 exhibit similar symptoms of cold, breathlessness, fever, cough and headaches and are from the same gene pool of bats. i.e., meaning the host of origin for both viruses is the bat. Even though they belong to the same family, they are different viruses.

They also differ in their virulence (severity of infection) and transmission rate. While the fatality rate of the SARS virus is around 9.6% (approx. ten deaths per 100 infections), the fatality rate of the Covid-19 virus is around 3% (approx. three deaths per 100 infections).

Additionally, while the R0 value (rate of transmission) of the SARS virus is less than 1, the R0 value of Covid-19 is around 3, meaning a single person infected with the Covid-19 virus can infect three other persons. In contrast, a SARS infected person can, mathematically speaking, infect no one.

Which virus is responsible for Covid-19?

The SARS-Cov-2 virus causes the disease Covid-19.

When did Covid-19 start in India?

The first case of Covid-19 reported in India was on January 27, 2020.

Can the coronavirus spread through the air?

Yes, respiratory aerosols can linger in the air for a few minutes and spread through the air.

Can people with mild Covid-19 symptoms recover at home?

People with mild Covid-19 symptoms can recover at home. However, if you have symptoms of breathlessness, you should immediately consult a doctor.

Can you catch Covid-19 after two doses of vaccines?

Vaccination does not necessarily protect you from infection, But what it does is that it reduces your likelihood of being severely ill from Covid-19. Severely ill means

  • Hospitalization
  • ICU
  • Death

How long does Covid-19 vaccine side effects last?

Covid-19 vaccination side effects usually last for a few hours to days. But it can be different for various people. Some may even have an overnight fever and flu-like symptoms.

What is Omicron, and what makes it a variant of concern?

The Omicron variant was first discovered in November 2021 across several countries. It is suspected to have 64% higher transmissibility rate, 1000 times more viral load, and 2.5 times more severity (hospitalization rate) than the Delta variant.

Can RT PCR detect Omicron?

RT-PCR can only tell if a person is infected with coronavirus, but it doesn’t exactly tell which variant.

The RT-PCR test looks for three components in the virus: the spike (S), the nucleocapsid (N2), and the envelope (E). Therefore, if N2 and E are discovered but not S, it could mean an Omicron.

How do we keep ourselves safe from Omicron?

  • Vaccination
  • Maintaining good hygiene
  • Social distancing
  • Wearing a mask
  • Avoiding indoor or crowded outdoor spaces
  • Good Ventilation

Do Covid-19 booster shots work?

Covid-19 booster doesn’t protect you from infections. But what it does is that it reduces the severity of Covid-19 symptoms.

Will there be a third wave?

If Ro >1, the pandemic will grow, and if Ro <1, the pandemic will reverse.

Omicron variant Covid-19 vaccine | Will the existing vaccines work against Omicron?

The existing vaccines can only reduce the severity of the disease, but they may not prevent you from being infected by the Covid-19 virus. So far there is no evidence that the variant is evading the vaccine induced immunity completely.

Why do variants of Covid-19 mutations occur?

Genetic mutations in viruses usually happen when they transmit from one host to another. i.e., the higher the infection rate, the higher the mutations. Mutations allow viruses to acquire a new ability to bind to host cells more efficiently and increase their chances of survival and reproduction.

Is it necessary to take two doses of the COVID-19 vaccine?

Yes. It’s necessary to take two doses of the Covid-19 vaccine.

Why do some people get fever after taking the COVID-19 vaccine?

Simply put, vaccines are nothing but weakened Covid-19 viruses or components of the virus injected into your system to generate an antibody response against the foreign substance. Whenever there is an infection or a foreign body in your system, your body generates an immune response against it by raising your body temperature.

What are the organs most affected by COVID‐19?

The Covid-19 virus primarily infects the lungs. But severe cases of infection can cause multi-organ failure.

Long term effects of Covid – 19 | What are some possible complications after recovering from COVID-19?

  • Weakness
  • Fatigue
  • Loss of smell and taste
  • Joint pains
  • Mood changes
  • Change in smell/taste
  • Rashes
  • Sleep problems

What are some of the COVID-19 Omicron variant symptoms?

Symptoms of Omicron are very similar to the symptoms of delta or ancestral variants. However, Omicron can differ from other variants in their severity and rate of disease transmission.

Does Covid-19 cause death?

The Delta variant has a fatality rate of 3%, i.e., three deaths per 100 infections. The Omicron is thought to have a fatality rate of 5% to 6%, i.e., six deaths per 100 infections.

How is Covid-19 treated?

Covid-19 can only be managed. As of date, there is no cure for the disease.

How is Covid-19 diagnosed?

Covid-19 is diagnosed through an RT-PCR test.

Can cats and dogs get Covid-19?

As of date, there is no evidence to show that Covid-19 infects cats and dogs.

Chapter 16: Latest Updates

What is Delmicron?

Delmicron could be a combination of Delta and Omicron variants. Even though there is no evidence that this strain has emerged as of date, scientists warn that this could happen as mutations are very common in viruses. Read more.

What is IHU Variant?

The IHU variant is said to have around 46 mutations and 37 deletions, some of which are located in the spike protein. A lot of research is being carried out across the world to understand its behavior. Read more.

Chapter 17: References:

  • Covid-19 information (1)
  • Shyamkumar Sriram, Availability of infrastructure and manpower for primary health centres in a district in Andhra Pradesh, India, Nov-Dec 2018. (2)
  • India’s Covid crisis (3)
  • An outbreak of Covid-19: An Overview (4)
  • Coronavirus disease pandemic (5)
  • Beta coronaviruses (6)
  • Delta coronaviruses (7)
  • Variants of concern (8)
  • Genetic mutation (9)
  • The Reproductive Ratio of Delta variant (10)
  • Advice for the Public (11)
  • People with certain medical conditions (12)
  • Covid-19 Myth Busters (13)

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