After months passing by in the COVID19 pandemic different countries have started competing with each other to be the first one to bring the vaccine in the market. It may sound like a good news but is it really? Everyone from the vaccine development area knows how vaccine development takes 5 to 10 years to get fully registered, but since COVID-19 pandemic is an emergency case we might say that we can put efforts to bring it as soon as possible, which might be around 2 years. So we need to know does the Sputnik V vaccine(Russia’s vaccine) really works or it is just part of a rat race and Russia may be putting national prestige before science and safety.
How the Sputnik V vaccine is made?
Sputnik V vaccine is based on the DNA of a weakened adenovirus. The adenovirus is used as vector to deliver small parts of the COVID-19 pathogen which help in stimulating an immune response.
Questionable points about this vaccine are:
1. The result of vaccine trials
Till now, Russia has made public the results of phase 1 trails but the result of trial 2 and 3 have not been disclosed yet, which is a matter of concern.
2. Lesser vaccine candidates
The vaccine was only tested on less than 100 people by early August which should be around 1000 and the reports did not specify whether all the three stages were over.
3. A fast-tracked vaccine may have unintended side-effects
One of the potential adverse events is antibody-dependent enhancement (ADE), a type of immune reaction where antibodies generated from the vaccine does not help to neutralise the virus but instead encourage the virus into cells to replicate by binding to receptors on host cells, which ultimately means that the virus is more likely to infect them. Examples: vaccines for measles, respiratory syncytial virus, and dengue virus, as well as in animal models for the original Severe Acute Respiratory Syndrome (Sars) virus.
Stating these issues in a recent editorial, immunologist and deputy editor of the journal Science Advances Dr. Douglas J. Green explained why bypassing essential clinical trial stages for any such vaccine could be ‘catastrophic by mentioning that although a COVID-19 vaccine is urgent, scientists cannot rush the development process
4. Identification of an immune correlate
Immune correlate means that we’re looking for a measurable immunological parameter that will tell us if someone is going to be protected against the virus after he or she is vaccinated. For example : antibody titre in the body.
Identifying such immune correlation and knowing the toxicity properly may take months to years after phase 3 trials as It is dependent on the rate of infection in the locations where the study is being conducted, as the goal is to compare how many people get sick in the vaccine arm of the trial versus the placebo arm.
How India and other countries are better in vaccine strategies?
Although India and other countries are taking their time to get the final conclusion to the vaccine but they are taking the risk factor as a major concern which is a positive aspect. There are so many cases where vaccine administration have led to another outbreak of the pathogen, these issue must be evaluated and must not be compromised at any case there should be a transparency of all clinical trials which is missing in Russia’s vaccine case.
In vaccine or any drug approval the risk to the benefit ratio is measured and if benefit is more than the risk the vaccine or drug gets approved but in emergency situations like the COVID19 pandemic the risk vs benefit balance changes and if death rate is higher with the disease then vaccine with significant side effects gets approval. So there should be alternative pathways and agencies to regulate such issues and should be based on correlation of immunity.
Green, D.R., 2020. SARS-CoV2 vaccines: Slow is fast.