Covid-19 Vaccine facts: how a vaccine ultimately works.

Vaccination campaigns have begun in many countries of the world to control the Corona pandemic. Information and suggestions related to this may seem intriguing to you at times, but there are some basic fact about covid vaccine that will help you to understand how a vaccine ultimately works.


covid-19 vaccine facts


What is a vaccine?

A vaccine is a type of medicine that trains the body’s immune system so that it can fight disease it has not come into contact with before. The vaccine contains some weak or inactive portions of the virus that cause disease. 

It stimulates the body’s immune system to identify infections (invasive viruses) and create antibodies against them, which help our body to fight against external invasion. It prepares your body to fight against any disease, virus, or infection. 

A very few people have the negative effect of applying the vaccine, but some people may have to face its side effects. Mild fever or rash are common side effects. You develop immunity to fight the disease only after the vaccine has been applied. 

The US Center for Disease Control and Prevention (CDC) states that “vaccines are very potent because they, unlike most drugs, do not cure a disease, but prevent it from occurring.”


What is herd immunity?

If about 70-90 percent of people develop immunity to a disease, then the rest will also be safe. According to experts, the coronavirus will produce herd immunity among people only when about 60 percent of the population has been infected. However, there is not even an opinion among experts about this 60 percent figure.

The World Health Organization estimates that at least 65–70 percent of people will need to be vaccinated to prevent infection, which means that more and more people will have to be vaccinated.

According to the principle of herd immunity, if a disease spreads in a large part of a group, then the immunity of humans helps the infected people to fight against that disease. Those who are completely cured after fighting the disease, they become ‘immune’ to that disease, that is, they develop immunological properties. 

Immunity means that a person has an infection and then their immunity has created antibodies capable of countering the virus. As more people become immunized, the risk of spreading the infection decreases, because now the number of people who can be affected by the virus is less.


how a vaccine ultimately works
The top box shows an outbreak in a community in which a few people are infected (shown in red) and the rest are healthy but unimmunized (shown in blue); the illness spreads freely through the population. The middlebox shows a population where a small number have been immunized (shown in yellow); those not immunized become infected while those immunized do not. In the bottom box, a large proportion of the population has been immunized; this prevents the illness from spreading significantly, including to unimmunized people. In the first two examples, most healthy unimmunized people become infected, whereas in the bottom example only one-fourth of the healthy unimmunized people become infected.

Are vaccines safe?

An early form of the vaccine was discovered by Chinese scientists in the 10th century. But in 1796, Edward Jenner found, a single dose of smallpox infection protects against a serious infection of smallpox. He studied it further. He also tested his theory and his findings were published two years later. That’s when the word ‘vaccine’ originated. The vaccine was coined from the Latin language ‘Vacca’ which means cow.

The vaccine is considered one of the greatest medical achievements of the modern world. According to the World Health Organization, about twenty to three million people are saved every year because of vaccines.

The Centers for Disease Control and Prevention states that vaccines are seriously tested before being brought to market. They are tested first in laboratories and then on animals. Only then the vaccine is trialled on humans. In most countries, vaccines are administered to people only after getting permission from local drug regulators. 

There are some risks in vaccination, but like all medicines, there is nothing in front of its benefits. For example, some childhood diseases that were very common up to a generation ago have become increasingly extinct because of vaccines. 

Smallpox, which killed millions of people, is now completely eradicated. The World Health Organization (WHO) declared smallpox eradicated in 1980. “It was eradicated solely through vaccination. 

But it often takes decades to achieve success. Africa was declared the only polio-free country nearly 30 years after the global vaccination campaign began. It is a very long time. Experts have warned that it may take months or possibly years to get adequate vaccination against the Covid-19, only after that we will be able to return to normalcy.


Comparison of Covid Vaccine

Fizer-BioNtech and Moderna’s COVID vaccine are both ‘messenger RNA vaccines’ that are used to prepare a portion of the virus’s genetic code. Instead of using a weak or inactive part of the antigen, these vaccines teach the cells of the body, how to make the ‘spike protein’ found on the surface of the virus that causes Covid-19.

The vaccines of Oxford and AstraZeneca are also different. Scientists have made some changes to a virus infecting the chimpanzee to prepare it and have also added a piece of the genetic code of Covid-19.


covid vaccine comparison
Comparison of covid-19 vaccines


All three vaccines have been approved for emergency use in the United States and Britain. Mexico, Chile, and Costa Rica have also begun to administer the fodder’s covid vaccine. While the Brazilian government has cleared the vaccines of Oxford and Synovac.


Are there more vaccines for Covid-19?

China’s pharmaceutical company Sinovac has created a vaccine called ‘Corona-Vac‘. It has been launched in China, Singapore, Malaysia, Indonesia and the Philippines. The company has used traditional methods to make this vaccine. According to the company, inactivated portions of the virus were used to make this vaccine.

However, a lot of questions have arisen regarding how effective it is. The vaccine was trialled in Turkey, Indonesia and Brazil. Scientists from these countries said after the final stage trials that this vaccine is only 50.4 percent effective.

Two vaccines are being prepared in India. One is the name Covishield, prepared by scientists from AstraZeneca and Oxford University and produced by the Serum Institute of India. And the second vaccine is COVAXIN made by the Indian company Bharat Biotech.

Russia has developed its own corona vaccine named ‘Sputnik-5‘ and it was developed by making a slight change in the version of the virus. The same vaccine is also being used in Argentina. Argentina has ordered three million doses of this vaccine for its vaccination campaign.

The African Union has also ordered millions of doses of the vaccine but has placed orders to several pharmaceutical companies. For example, the African Union has ordered vaccines to Pfizer, AstraZeneca (via the Serum Institute) and Johnson & Johnson. The company, Johnson & Johnson, is currently unable to finalize its vaccine.


The importance of vaccination?

According to the Centers for Disease Control and Prevention, the vaccine not only protects against covid-19 but also to protect others. In addition, the CDC also describes vaccination as the most important way to get rid of the pendemic.

The World Health Organization estimates that at least 65–70 percent of people will need to be vaccinated to prevent infection, which means that more and more people will have to be vaccinated.

There are a lot of people who have many doubt about the preparation’s speed of the covid vaccine. It is true that scientists spend years developing a vaccine, but the speed has been greatly increased to find a solution to the corona epidemic. 

That is why the World Health Organization is working closely with scientists, business and health organizations. In short, the vaccination of billions of people will prevent the spread of Covid-19 and the world will move towards the herd immunity

Experts say that only through herd immunity, the world will be able to return to normal life.

Rajat Red

Admin and Founder of "UNTOLD SCIENCE | Exploring The World Of Science & Nature". He is a science student pursuing B.Sc in Biology from India. He is a curious being and an explorer, who has an interest in many fields besides science. But, He loves to study and write about science.

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