We have two vaccines in India Covishield by SII and Covaxin by BB.
One is a botched up trial and another with no phase-3 trial data and phase 1 and 2 data not being peer reviewed.
A lot fiasco is going on Covaxin so, lets first talk about the less talked first and then (1/n)

will move to the other one.

In trial of covishield in UK, Brazil and South Africa trial protocol was breached by “mistakenly” mis-administering half first dose in some participants which astonishingly gave results of 90 % efficacy in this group. Though the sample size (2/n)

Of this group was quite small (1367 0n vaccine arm and 1374 on placebo arm) to conclusively infer anything. While, in case of full dose the efficacy was found to be around 60 %. This difference is not backed by even any sound theoretical explanation till date (3/n)

This very “mistake” thus took overall efficacy of vaccine from 60% to 70%. In ordinary circumstances this trial would have been void in breach of protocol and regulators would have asked them to redo it. But, of-course its a all raving pandemic so this exception. (4/n)

In India they are conducting a phase-3 trial with a sample size as small as 1600, which is little more than sample size of phase-2 trials and doesn’t serve the very purpose of phase-3 trials which is assessing safety and efficacy in larger population with various conditions (5/n)

Even in this trial participants were given paracetamol which more likely had affected adverse events by either turning severe adverse events to moderately adverse events and diminishing moderately adverse and thus not giving a clear picture of safety of the vaccine. (6/n)

Another, aspect is the except trial in South Africa its trial had been single blind and not double blind which does leave room for experimenter bias and thus, is lesser reliable. While on another hand the trial of Covaxin is double blinded and its data “would” inspire (7/n)

More confidence. But there should be data on the first place to analyze, question and inspire confidence.
Though how much so ever inspiring phase 1/2 trial data may be but its too small to infer or opine anything.
Covaxin is an inactivated whole virion vaccine(8/n)

which is time tested as against to viral vectors like covishield which yet have to stand the test of time and prove its mettle constantly evolving and mutating pathogen Virus.
As covaxin uses whole inactivated virus it is theoretically expected to broader immune response (9/n)

As resultant and thus being more effective in case of mutation of virus as compared to viral vectors and mRNA though giving strong immune response is not broad.
But, Medicine is not Mathematics where we can have one fit formula for all. For everything we need to study (10/n)

Examine, collect data, analyze and then conclude anything.

As being claimed by Bharat Biotech, Covaxin had prevented infections in Chimpanzee, hens and etc but to even imagine this case of humans we need data which is not there, though if it gives similar results (11/n)

In humans it could be our biggest weapon against covid, safe, time tested, preventing infections thus transmission too and not only preventing disease.

Inactivated virus vaccines are known for having least side effects and can be safely administered to people with (12/n)

Pre-exising conditions.

The ongoing rage of second wave in Europe and US are forcing them to try various variations of doses of vaccines so that more people can be vaccinated and fatalities could be lowered which are sky rocketing at the moment. But, this variation is (13/n)

Also a diversion from the proven data of efficacy and is like administering a vaccine which is safe but its efficacy is unknown.
After all, desperate situations need desperate measures.
The delay in second dose we really don’t know will end up in what, all are just (14/n)

Mere assessments of course impacted with personal prejudices. This could save thousands of lives but in all likelihood in case of weaker immune response might result in more and faster mutations, which could actually make things worse.

Furthermore, a false sense of (15/n)

being immune can actually make people go more reckless, we all might have seen people who got infected and recovered start acting as if they are immune and immortal thus in the end lower the guard which could make things worse.

In case Covaxin, there are too many unknowns (16/n)

though even presuming it to be safe giving a false impression of its being effective to people having it could lead to more bad than good. But, using it in an absolute haywire situation could be a gamble worth taking but that day is not today at least here in India. (17/n)

Even in case of efficacy do understand a vaccine with as high efficacy as 95% only means that in trial it prevented disease in 95% more people with vaccine as compared to placebo. The immune response rendered by a vaccine is independent of this consideration by all means (18/n)

Either it works for you or it don’t, there is no in between.

Efficacy of a vaccine is a population based assessment not an individual assessment.
Though a vaccine could be efficacious in preventing disease but that doesn’t mean it will prevent infection too.

(19/n)

Given a choice of having vaccine today what will be your take?