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Things to understand about COVID-19 vaccines

How do COVID vaccines work?

The vaccines use messenger RNA or mRNA. Coronaviruses have a spike-like structure on their outer surface called S protein. On inoculation, the Covid 19 mRNA vaccine gives body cells instructions on how to make a harmless piece of S protein. The cells then start constructing the protein pieces and display them on their surface. The system recognizes that the protein doesn't belong there and begins building an immune response of antibodies as a countermeasure.

The world geared up in 2020 to meet the pandemic challenge in a collaborated way and has reached some success of developing effective Covid vaccines. In this short span of time from vaccine development perspective, more than a dozen vaccines have been authorized for use

around the globe; and many more are in various stages of development.

Why should we get vaccinated for COVID-19?

Knowing that there is no proven cure for Covid as on date, a vaccine can:

  • Prevent an individual from getting Covid 19 or becoming seriously ill from Covid19.

  • Prevent one from spreading the Covid 19 virus to others in the community.

  • When an increased number of people in the community are vaccinated then it becomes harder for the disease to spread. A protracted effort of everyone can contribute to herd immunity.

  • It will prevent the Covid 19 virus from replicating. If the process is not stopped then the virus can keep mutating and become more lethal and resistant to medicines.

Side effects of COVID-19 vaccine

A Covid-19 vaccine can cause mild side effects after the first or second dose, which may include:

· Pain, redness or swelling where the shot was given

· Fever, Fatigue, Headache

· Muscle pain, Chills, Joint pain

· Nausea and vomiting, or

· Swollen lymph node

An inoculated person is monitored for 30 minutes after getting the vaccine to see if there is an immediate reaction. Most side effects happen on the day of vaccination and they last only for one or two days.

Types of COVID vaccines available in market

The menace of COVID is unique in the sense that no country in the world can claim a win in isolation until everyone wins. To this extent vaccination drive with the following vaccines has been started by the countries to make a humble beginning to slowly eradicate this menace;

Comirnaty – BioNTech: The vaccine has been developed by Pfizer. It’s an mRNA based vaccine which is available in 56 countries.

Moderna: The vaccine is developed in the USA and made available only to a select group of countries in North America, EU and India owing to its priority use in the country of origin.

Covishield – AstraZeneca: It’s the most widely available vaccine around the world. Manufactured by Serum Institute of India, the vaccine is highly effective with efficacy numbers of more than 85%.

Sputnik V: It’s also a recombinant adenovirus vaccine which is developed by the state owned research institute in Russia. In India the vaccine is being imported by Dr Reddy’s. 3 batches have arrived in while the company has promised to produce more at its Hyderabad facility in

the coming days. It has also signed a 3 year manufacturing contract with Shilpa Medicare to accelerate its production and supply for local use.

CoronaVac – J&J: This vaccine is different. It’s based on non-replicating viral vector. Viral vector-based vaccines differ from conventional vaccines in that they don’t actually contain antigens, but rather use the body’s own cells to produce them. The efficacy of this vaccine is low at 65% and is available in less than 20 countries. 

Covaxin-Bharat Biotech ICMR: It’s an inactivated vaccine. Inactivated virus vaccines do contain the disease-causing virus, or parts of it, but their genetic material is destroyed. For this reason, they are considered safer and more stable than live attenuated vaccines, and they can be

given to people with compromised immune systems.

Covid-19 Vaccines: What's expected next?

A Nanoparticle based vaccine is being developed by Novavax, which is in Phase 3 stage and so is Zycov-D, a DNA based vaccine that’s being developed by Zydus Cadila in Ahmedabad.

Another contender that holds good promise is an experimental vaccine being developed by Sanofi GSK. While its phase 2 trial showed 95-100% efficacy in all age groups of 18-95 years, a final stage 3 trial will be underway soon.

How long will it take to build immunity after getting the covid-19 vaccine?

While there appears to be some protection 14 days after a person’s first dose, that may wane over time, which is why it’s imperative to get the second shot. There has been talk of using one dose of the mRNA vaccines in the developed world, but all scientists are not on board with this proposition. The general consensus is that the protection provided by the first dose of these vaccines is a bridge to the next dose.

The body immunity is generally achieved somewhere between 7 to 14 days after the second dose.

Are there any suggested safety precautions after vaccination?

Vaccine doesn’t mean perfect immunity. Vaccinated people should continue to take safety precautions, such as wearing masks and avoiding close contact within 6 feet or 2 meters with others in public places whether indoors or outdoors where there is a high risk of Covid 19 transmission.

Crowded gatherings or close proximity with unvaccinated people including children from other households can still cause Covid despite being vaccinated. Same is the case when living indoors with people who are at an increased risk of severe illness due to comorbid conditions.

Is it safe for pregnant women to get Covid vaccine?

While the data about safety of Covid 19 vaccines for pregnant women is limited right now, there’s no evidence to show vaccines are linked to infertility or miscarriage. Basis what is known, the data doesn’t show any increase in miscarriage rates among pregnant women with Covid, as women with Covid would generate the same antibodies anyways as a Covid vaccine.

Why is there scepticism about Covid-19 vaccination?

In a large country like India there are groups of people who are hesitant about vaccination though that’s the only hope against Covid as of now. Some mid-aged people who are in the age group of 30-45 years don’t want to get vaccinated right now. Some of them say that they are asthmatic that puts them in a high-risk category, yet there isn’t enough courage to get swayed for vaccination.

It’s a tough situation for the administration. Trust is based on emotions, but some people are not ready to trust the authorities at this point. It’s not that they are not educated or believe in any conspiracy theories but the concern for what might go wrong in future just pulls them back.

People in general want to know long term negative effects caused by the vaccine but there isn’t enough evidence to show implications, serious or otherwise, since the vaccine is new.

For the efficacy data ranging between 66% to 91% for various vaccines which are in public domain most people don’t doubt that vaccines are safe but since they haven’t been out there long enough for scientists and doctors to really know the long-term effects, certain people are hesitant.

What builds confidence to go for vaccination rather than fear of keeping away from it?

These are modern times. Science has evolved much since the last global pandemic the world witnessed. Scientists, Medical experts and Doctors in authority who voted for emergency use of Pfizer, Oxford, AstraZeneca, Moderna, Bharat Biotech and SII say that the vaccines are safe. None of the steps that are typically involved in evaluating the safety have been omitted. The protocols are well defined and they’re all followed to completion, and as on date they all demonstrate that the vaccines are safe and effective.


Sunil Kumar Kalra

901 4357 509

Whatsapp +7 916 227 5503

Sunil Kumar Kalra, LLB from Delhi University is a practicing Advocate in the Supreme Court of India, New Delhi and NCDRC Delhi. He was formerly a Vice President at Dr Reddy’s Laboratories and Genpact LLC.

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