Mixed feelings on the approval of two vaccines in India. Happy to see India finally get going on vaccines, but serious doubt over the process & evidence used. There's a complete lack of transparency and accountability (no questions taken during the press briefing). Thread 1/n

Let's first get the names right because news reporting has not been very clear.
Covishield is the vaccine that's been developed at Oxford University in partnership with Astrazeneca. It's being producted at the Serum Institute of India (hence being called Serum vaccine) 2/n

The second is the indigenously developed vaccine by Bharat Biotech, called Covaxin. The Oxford-Astrazeneca vaccine has undergone large-scale human trails (aka phase-3 trials): the data has been shared & results have been published in peer-reviewed journal. 3/n

Unfortunately, the same is not true for the Bharat Biotech vaccine. As per reports, it's phase-3 has not been concluded — *no data has been shared & results have not been published in any peer-reviewed journal*. This is the main controversy with its approval. 4/n

Remember that despite being called 'restricted emergency usage' (whatever that means), at the end of the day the *vaccine will be administered on healthy individuals* who do *not* have the infection. Hence, there can be absolutely no doubt over safety. 5/n

How do we remove any doubts over safety of a vaccine? By making the data public, opening it to scrutiny by researchers all over the world. Bharat Biotech, so far, has done none of this. Whatever data the 'expert panel' has relied on for the approval, must be made public. 6/n

This is not some unwarranted skepticism towards vaccine; this is a crtique for compromising the scientific process that is supposed to remove any doubt. This is not some anti-vaxxer crap or 'unwarranted cynicism' from a critic of this govt. 7/n

On the other hand, I'm happy with the approval for Oxford-Astrazeneca vaccine. The trial results, as per experts, suggests that it's safe (usually mild side-effects, very few adverse side-effects which were easily brought under control). All of this is in the public domain. 8/n

So, even if the efficacy of Oxford-Astrazeneca in preventing the infection may not be as good as some others like Pfizer & Moderna vaccines, given the much easier logistics & lower cost, it's better than having nothing (because it's safe!). Can't say the same about Covaxin. 9/n

Does it mean Covaxin (Bharat Biotech) won't work / necessarily have serious side-effects? We don't know. It may very well work, but we currently don't have the data to confidently say that. Hence, we need to be very careful & must not act based on mere speculation. 10/n

Also, I wonder why Pfizer, which has publicly made available data on its safety & efficacy, has not been given approval but Bharat Biotech has? Perhaps, all of this boils down to govt's obsession of being in line with 'Aatmanirbhar Bharat' rhetoric. 11/n

Whatever it might be, it raises serious questions & it's bad science.
In sum, I welcome the approval for Oxford-Astrazeneca vaccine but I'm highly skeptical of (if not absolutely outraged at) the approval for Bharat Biotech vaccine. 12/n

Note - I'm not a medical expert. I just deeply care about the scientific process & read a lot on it. I have taken some online courses on disease modelling in the context of Covid-19. All of this is based on fairly careful literature review on this front. n/n

This sums up my thread: https://twitter.com/Joydas/status/1345734385165717504?s=19

Here's an important read from Dr. Gagandeep Kang, vice-chair for the board of Coalition for Epidemic Preparedness Innovation (CEPI). https://m.timesofindia.com/india/i-have-no-clue-i-have-never-seen-anything-like-it/articleshow/80087336.cms

Many saying Covaxin is only for emergency situation, as a backup option against the new UK strain. How does that make any sense? How do we know that it'll work at all – let alone UK strain – without complete data. Remember, 'likely to work' is different from *proven to work*.