PSA answers questions on the science of vaccines. Please watch: https://www.indiascience.in/ 

PSA says that if we didn't do trials, we wouldn't be able to answer questions on immunogenicity and efficacy. And well-to-do, educated people should participate in trials, and participation is a public good and pride.

A viewer asks: should I get my 9 year old daughter vaccinated. Ans: Vaccine trials take place in defined (age) groups. Hope @PrinSciAdvGoI answers how BB vaccine was licensed in children even though Phase 3 trial didn't include children. And Phase 2 enrolled 14 children.

He says that sometimes the vaccine trials are expanded to age groups that weren't included in trials if benefits overweigh risks. My addition: But we do not know the benefits (efficacy) of the BB vaccine at all.

He takes my Q about why Dr. Guleria claimed the vaccine was safe, when we don't even know if a 7-day safety assessment was done after first dose. He says that the safety assessments happen at multiple timepoints. (Me: surely the 28 day timepoint after second dose is critical?)

Also, which safety timepoint is complete so far for all participants who received one dose? Why not share this data while claiming the vaccine is safe in half of the 22500 given the jab? Isnt this more relevant and specific information?

PSA answers question about whether vaccines are efficacious against "mutated virus". PSA says there is nothing such as a mutated virus - there are many mutations

Talks about the so-called UK strains, which has key mutations that increase transmission. Also SA strain, and another in a Danish mink colony which decreased immune response.

In these cases, he thinks molecular analysis etc suggests current repertoire of vaccines will work.

Says that speedy vaccination is important to prevent these problematic strains from growing exponentially.

Says if disease is life threatening, like in Anthrax, vaccine can be deployed after Phase 1 or 2. Says that because of huge impact of Covid on large population, and likelihood of mutations arising, vaccination is important

Me: Hard disagree. SARS-COV-2 has a very low mortality rate compared to Ebola/Nipah. At individual level, chances of developing severe disease is low (not true with Ebola). Important to establish that benefit overweigh risk for a large population @GKangInd's would be good to know

@GKangInd has also shared an opinion during an interview with The Wire that Ebola and SARS-COV-2 are different, and this doesn't warrant approval of vaccine after Phase 2.

Dr Vijayraghavan clarifies that he agrees that Ebola and SARS-COV-2 are not same in terms of mortality. And that the consideration here is that SARS-COV-2 infects large numbers, increasing likelihood of dangerous mutations arising. Hence, widespread vaccination is a priority.

Again, this is very very debatable. We have to remember that MEURI protocols were developed *after* the dilemmas that Ebola raised. And MEURI protocols place great emphasis on Phase 3 trials. See my story here about MEURI: https://science.thewire.in/the-sciences/icmr-covid-19-hydroxychloroquine-prophylaxis-meuri-guidelines-clinical-trials/

For Ebola, researchers did all sorts of gymnastics and devised innovative trial designs to actually test Ebola drugs in Phase 3 trials. They actually happened.

In fact, Ebola is a brilliant example of how much Phase 3 trials were *prioritised*. These trials were conducted during a time of considerable political instability, with a high mortality disease.

PSA says questions about vaccines must be answered, but the value of vaccines must be communicated to. I agree. Vaccines are important. Very. The question is: which vaccine? Each one is different, with different clinical data supporting it.

India unfortunately has fewer choices, because of the cold-chain requirements of Pfizer and Moderna vaccines. But I don't know if the answer is to approve a vaccine before we know anything about its efficacy.