Final-stage testing of experimental COVID-19 vaccine, developed by the National Institutes of Health and Moderna Inc, has begun with volunteers at various United States sites given either a real shot or a dummy without being told which is what.
It will be months before results trickle in, and there is no guarantee the vaccine will ultimately work against the scourge that has infected nearly 1.65 crore people and killed about 6,50,000 COVID-19 patients around the world.
Several other vaccines made by China and by Britain's Oxford University began smaller final-stage tests in Brazil and other hard-hit countries earlier this month.
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In India, the human clinical trial of indigenously developed Covaxin has begun in Odisha.
Frequently Asked Questions
A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.
There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.
Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.
Here are the latest updates on the development of COVID-19 vaccine:
> The human clinical trial of indigenously developed Covaxin, a possible vaccine against novel coronavirus, has begun at the Institute of Medical Sciences (IMS) and SUM Hospital in Bhubaneswar, Odisha. It is one of the 12 centres selected by the Indian Council of Medical Research (ICMR) for conducting phase one and two of the process.
> The world's biggest COVID-19 vaccine study got underway on July 27 with the first of 30,000 planned volunteers helping to test shots created by the US government -- one of several candidates in the final stretch of the global vaccine race.
> Five sites in India are ready for the third and final phase of human trials of the Oxford-AstraZeneca COVID-19 vaccine, said the Department of Biotechnology (DBT) Secretary Renu Swarup. This is an essential step because it is necessary to have data within the country before the vaccine is administered to Indians, Swarup told news agency PTI.
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> The Serum Institute of India is conducting phase III clinical trial of BCG vaccine candidate VPM1002 to evaluate its ability in reducing infection and severe disease outcomes of COVID-19 among high-risk persons of advanced age, comorbidities and high-exposure healthcare workers (HCWs), according to the Department of Biotechnology.
> German biotech BioNTech and US drugmaker Pfizer Inc have said that they would begin a pivotal global study to evaluate their lead COVID-19 vaccine candidate. If the study is successful, the companies could submit the vaccine for regulatory approval as early as October, putting them on track to supply up to 100 million doses by the end of 2020 and 1.3 billion by the end of 2021.
(With inputs from agencies)
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