Covi19 Explained: The world’s largest COVID-19 vaccination program has started in India from January 16. So far in the first phase, two doses of vaccine have been given to more than 7 lakh people. Some people, including doctors and other healthcare workers, are hesitating to take the vaccine. Because of this, many questions have arisen regarding the vaccine. In an Indian Express report, all the questions have been answered, such as how the vaccine works and how the corona vaccine became so quickly etc.
The vaccine is prepared by scientific methods. If in making it, the scientific method and process have been followed on the basis of data and facts, then there should be no doubt about it.
This is how the vaccine works
A vaccine is a substance that is similar to a disease-causing virus or bacteria called a pathogen. When it is vaccinated, it trains the body’s immunity and prepares a memory. When a virus or bacteria (pathogen) infects the body in the future, memory is immediately deployed to eliminate it and is not able to cause disease in the body.
Life of 20-30 lakh people saved annually from vaccination
Many diseases have been conquered due to the vaccine. In addition to the cessation of smallpox and the near termination of polio, the vaccine has ensured protection from 20 other life-threatening diseases that could have killed 20–30 million people annually. The Universal Immunization Program in India is the largest in the world and under it about 26 million children are vaccinated every year. According to an estimate, a dollar (Rs 72.98) spent on immunization of children adds $ 44 (Rs 3211.01) to the economy as it will keep them healthy as they grow up in childhood vaccinations and contribute significantly to GDP.
The vaccine is prepared in three stages
It takes many years to get the vaccine ready. Firstly, a proof of concept is prepared in the research lab. Then after that, controlled manufacturing processes are developed for permanent and highly pure products. After that, it is tested on animals. Then it is tested on humans to check the safety and effective efficiency. Clinical trials on humans are done in three stages.
- First stage: In the first phase of the clinical trial on humans, 20–100 healthy volunteers are given vaccine doses to see how safe the vaccine is. If the vaccine is effective, it is studied for its serious side effects and dosage.
- Second Stage: It is tested on a few hundred volunteers. In this phase, the most common side effects of the vaccine in people are studied, which are effective for some time. Also at this stage, it is seen how the body’s immune system is reacting to the vaccine which in a word is called immunogenicity.
- third step: In the last phase, thousands of volunteers are trialled in ‘Blind Manor’. Blinded manor means that two groups are formed in which one group is given a vaccine dose and the other group is given a placebo or dummy vaccine. However, volunteers do not know whether they have been given the original vaccine or the dummy. In this phase, safety is studied again and serious side effects are studied. The most important study at this stage is whether the vaccine is capable of preventing infection or disease.
Due to this, the corona vaccine became early
- It takes many years to get the vaccine ready, but the corona vaccine was ready within a year. At present, the human clinical trial of 68 corona vaccines is underway, out of which 20 have reached the third stage and eight have been approved for emergency use. Apart from this, two have been approved for full use. The biggest reason for the Corona vaccine to be created so soon is that the scientific information was shared publicly and the virus is similar to that of SARS-Kovi-1 and Mers, which has already done a lot of work. Its genome sequence became available on 11 January 2020 and the trial of the Moderna mRNA-1273 vaccine began in the first phase in the US within just 63 days.
- In addition, regulators approved clinical testing and data review for parallel stages with a view to speeding up the process of vaccine making. Governments also invested heavily on this and encouraged the vaccine to be developed regardless of the financial risk for the pharma companies through the innovative financial model.
- Another reason for the formation of the corona vaccine as soon as possible was that all available vaccine platforms were used for this. Those platforms have also been used which have not yet developed vaccines for humans. Pfizer / BioNotech and Moderna used this technique to directly enter the mRNA fragment in human cells and produce viral spike proteins that enhance anti-viral immunity. The special thing is that this technology is in the development process for making an anti-cancer vaccine for the last ten years.
- Apart from this, the development of non-replicating viral vectors was going on for the last few years. Experimental adenovirus-based Ebola vaccine was applied to about 60,000 people in 2014–16 in the case of the Ebola virus in West Africa. Researchers at Oxford University were using the chimpanzee adenovirus platform to produce some experimental vaccines that were used to make the COVID 19 vaccine. Thus, an inactivated (inactive) virus-based vaccine has long been a tested method used by ICMR / Bharat Biotech. In this way, China has prepared at least three vaccines.
- However, it is also important to know the limits of all platforms. The mRNA is a fragile molecule that needs a safe environment such as frozen storage. Because of this, there is a problem in its storage. Viral vector vaccines are more stable and can be maintained at temperatures of 2–8 ° C. The problem with the viral vector vaccine is that the same vector cannot be used for other diseases on the same person because the anti-vector immunity will eliminate its effective potential. Viral vaccines are generally considered safe, but the use of a similar vaccine against the respiratory syncytial virus and measles was forbidden because they could aggravate the disease.
Based on test-tested technology
The epidemic has given a huge opportunity to reduce the time taken for vaccine development without compromising safety. Regulators have begun approving Emergency Use (EUA). Under this, the availability of vaccine is ensured at the time of the public health emergency. However, safety is not compromised in this mechanism and Phase 1 and Phase 2 are reviewed in it. Apart from this, data of about two months (US regulatory FDA) or 70 days (European Medical Agency) are also evaluated in Phase 3 followup. An interim analysis is also carried out for the effective potential of the vaccine. After this, approval is given for emergency use of the vaccine in view of the greater risk of infection.
In India, questions were raised about Bharat Biotech’s cocaine because it is currently in clinical trial mode. Apart from this, it was called as a backup vaccine and it was said to be less good than other vaccines. However, Covaxin is based on tested test technique and is generally considered safe.
Covid-19: Who should not get Covaxin vaccine, Bharat Biotech released a factsheet
How effective the vaccine against coronavirus mutants
The coronavirus is mutating slower than other RNA viruses. Despite this, new variants appeared in Britain, South Africa and Brazil and now it has spread to 50 countries including India. There has been a change in the spike proteins of these viruses, due to which they are able to easily enter the cells of the body. According to an estimate, the UK variant of the coronavirus is spreading 30–70 per cent more rapidly. According to preliminary data, the coronavirus can be eradicated through blood serum of people who have recovered from corona infection, even if it has become a mutant.
It is not possible to say anything now when the vaccine has failed. Those who have developed a corona infection despite being vaccinated should be examined to find out which variant of the corona they have been infected with. Apart from this, it is yet to be studied whether patients recovering from corona or vaccinated people can neutralize this variant from the serum.
Infected people can wait
More and more people are being advised to get vaccinated. According to the data available so far, the antibodies produced in those who have become corona positive, last for three to five months. However, the body’s resistance ability is able to protect for some more time. In such a situation, if the supply of vaccine is not enough, then people who have got corona infection once, can stay for a few months. However, the chances of shortage of its supply in India are less.
