COVID-19 vaccines : Facts and fiction

Dr Sanjeev Gulati *

A vaccine is a biological preparation that provides active acquired immunity against a pathogenic organism which causes an infectious disease. It usually contains a biological preparation that is produced a from weakened or killed forms of the pathogenic organism, its toxins, or one of its parts (surface proteins).

This stimulates the body’s immune system to producing antibodies against it like in case of infections. These antibodies recognize and destroy the microbial agent that it may encounter in the future. Thus a vaccine prepares your immune system to fight off germs if you come into contact with them in the future.

The concept of vaccination is not new and smallpox and polio are examples of diseases that could be eradicated because of effective vaccines. There are many other infectious diseases that have been brought under control because of effective vaccines. Most vaccines are given as injections (single or multiple) although some can be given orally like the polio vaccine and the typhoid vaccine.

Vaccination is one of the prime reasons of reduction in mortality rate of infants and children. At the same time it is not a child’s play to develop a vaccine. Each vaccineis tested in thousands of healthy volunteers and the data analysed and reviewed by experts before it is approved and ready for clinical use. The average time to develop a vaccine against infectious diseases is about 10.7 years.

However we still do not have effective vaccines against HIV and Hepatitis C despite several years of research and efforts. Considering that the development of a vaccine against COVID-19 took less than a year, it is nothing short of a scientific miracle. The Indian Government needs to be commended for rising to the occasion.

It ensured timely availability of the vaccine and also provided the necessary regulatory approvals. Most important it has set up vaccine delivery network to deliver and monitor the safe delivery of these vaccines. As a result several lakhs of health workers have already been vaccinated. Despite the availability of vaccines, vaccine hesitancy remains a prime issue.

There has been a lot of apprehension into only in the minds of the general public but also amongst the health workers. This has further been complicated by reports in social media and lay press over possible vaccine related complications.

All this has resulted in a low acceptance rate despite the commendable efforts done by the Indian Government in providing these vaccines at their doorstep and that too free of cost.

To allay this fear and educate the public we discuss various issues related to COVID-19 vaccine .

What are the different types of vaccines available ?

Currently there about 9 different vaccines available in different parts of the world. These are of different typyes (a) are mRNA vaccines (b) viral vector vaccines which have harmless adenovirus with the Covid spike protein incorporated (c) inactivated viral vaccines . The two vaccines licences in India are (A) COVISHIELD which is an adenoviral vector vaccine (b) COVAXIN which is a inactivated virus vaccine

How do I know which vaccine is safe ?

All vaccines have to pass through animal studies first followed by Phase1, Phase 2, and Phase 3 trials before they are licensed and ready for use. These trials are monitored by an independent group of experts which can stop the trial if any adverse effects are reported. All the above vaccines have gone through these trials and have been found to be safe.

Each of these vaccines has followup data of several months on human volunteers none of whom developed any major side-effects. However phase 3 trials of a few of the above vaccines are still in progress and data is still awaited. They have received emergency use authorisation in view of the clinical situation.

Can I get Covid infection from the vaccine ?

You may develop symptoms of viral infection like fever and myalgia but you cannot get COVID 19 infection as none of the vaccines contains a live virus.

Why should I get the vaccine ?

Since November 2019 COVID-19 has played havoc all over the world resulting in millions of deaths and leaving others with severe lung and heart damage. Scientists believe that vaccines are one of the cheapest and the most effective ways to control the COVID-19 pandemic. The pandemic is till continuing and newer variants of the virus are emerging .

The benefits of the vaccine far outweigh the risk of Covid infection and its complications. In addition if you develop COVID-19 infection you may spread the infection to your near and dear ones and put them at risk.

Can I choose which vaccine I will get ?

As of now the vaccine is being delivered and monitored by Government agencies and you cannot choose which one you will get. Once they are available commercially in the open market you may be in a position to choose.

Who should not get the vaccine ?

If you have had a severe allergic reaction to a dose of COVISHIELD you should stay away from the 2nd dose. However a history of minor allergies is not a contraindication to taking a vaccine.

Can it be given to pregnant and lacatating mothers ?

As of now these vaccines are not recommended as safety data in these types of patients is till awaited. It is likely that they will be eligible to receive the vaccine in the future once we have more information.

Should the vaccine be given in immunosuppressed individuals ?

Yes these patients with kidney disease, cancers, transplant patients, liver disease should take COVISHIELD as they are at very high risk of dying or developing severe Covid disease and complications. For COVAXIN , in view of lack of data it is being advised that it should be avoided in patients on blood thinners, immunocompromised conditions

What are the side effects?

The most common reaction like other vaccines is a mild fever, headache, pain where you got the shot (upper arm) and feeling of tiredness. These symptoms usually go away in 1-2 days. There is a risk of serve allergic reaction or anaphylaxis. Hence it is mandatory that you be monitored for 30 minutes in the observation room as per protocol.

Do patients still need the Vaccine if they had Covid ?

Yes they still need the vaccine as studies have shown that the Covid antibodies in blood of these patients are variable and decline with time. Thus they are not protected in the long run.

Do people still need to practice social distancing and wear a mask after getting the vaccine?

Yes 2 doses are required for protection and the immunity usually develops abut 2 weeks after the 2nd dose of the vaccine. Hence you still need to practice SMS: Social distancing, Masks and Sanitisation of your hands . These will have to be continued till herd immunity develops.