HomeNewsOpinionCoronavirus vaccine | History of trials does not offer too much comfort

Coronavirus vaccine | History of trials does not offer too much comfort

In the pharma industry, the gap between trials and eventual products is huge and there is a tragic history of drugs that have had to be culled just short of being put out in the market. Roughly 9 in 10 drugs and biologics that are tested in humans don’t even reach the US Food and Drug Administration (FDA) for its approval even after Phase 3 testing

August 16, 2020 / 11:42 IST
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Representative image
Representative image

Instead of dissing Sputnik V, the COVID-19 vaccine developed by the Moscow-based Gamaleya Research Institute, we should actually be praying for its success. As indeed we must for all the 40-odd vaccine candidates currently in Phase 1-3 trials, as well as others that are still in pre-clinical stages of development and research. The reason is simple: there is no guarantee that any of them will eventually be successful.

In the pharma industry, the gap between trials and eventual products is huge and there is a tragic history of drugs that have had to be culled just short of being put out in the market. Roughly nine in 10 drugs and biologics that are tested in humans don’t even reach the US Food and Drug Administration (FDA) for its approval even after Phase 3 testing. This after companies go through extensive multi-centre, double-blind trials across the world to evaluate their efficacy and safety.

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In a 2017 study, the FDA (https://www.fda.gov/media/102332/download) looked at 22 case studies of drugs, vaccines and medical devices over the previous 18 years in which promising Phase 2 clinical trial results were not confirmed in Phase 3 clinical testing. It found that the Phase 3 studies did not confirm Phase 2 findings of effectiveness in 14 cases, safety in one case, and both safety and effectiveness in seven cases. In two cases, the Phase 3 studies showed that the experimental product increased the frequency of the problem it was intended to prevent.

These were drugs from large pharma companies such as Roche, Bristol-Myers Squibb, Sanofi and addressed such pressing problems as reducing the symptoms of schizophrenia, hepatocellular cancer and breast cancer.

COVID-19 Vaccine
Frequently Asked Questions

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How does a vaccine work?

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.

How many types of vaccines are there?

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.

What does it take to develop a vaccine of this kind?

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.
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