I don't expect all of that to pan out. The current Govt Aug-Dec estimate is in this PIB image:
* Covishield 75cr doses = 15cr/month
I think they won't hit 150m/month until sometime in the middle of H2. Not really failure - it's hard to scale up processes to such a large volume in a single plant. It is easier to make volume out of multiple places. That's why...
* Covaxin: 55cr doses = 11cr/month
I think they will exceed this. Currently they are augmenting a second line in Hyderabad, which has increased their capacity from 0.5cr doses per month in Jan/Feb, to 3cr this month. They opened their Bluru facility this month, and they expect all three together to reach 7cr in July/August. The same month, IIL and BIBCOL (both of whom got 70cr last Nov to expand BSL-3 facilities) come online, and that's how they reach 100m+ which they can increase to 120m without a lot of incremental effort. If the new
Pune facility comes online, Covaxin can scale up to 15cr/month instead of 11cr. Then Haffkine comes online sometime between 4Q2021 and 1Q2022. That will send total higher than 150m, i.e. exceeding Covishield single line output.
Among the rest, Sputnik is the most credible figure since it is already approved and being made elsewhere. Zycov-D and Biological-E may clear Ph3 in May/June, but the latter has greater stated production ability. The rest depends on things coming together on time. Gennova is working hard but their Ph2 trials are taking longer than hoped. BB Nasal vaccine is a whole new mechanism. Novavax remains vaporware right now, to quote an IT-vity term.
I expect we'll sustain 250-300m doses/month in H2, which means 8-10m doses a day.
Some people have argued why the scaling up is not linear. Well it is not linear anywhere. If anything Indian output has been remarkably consistent in maintaining stability and not regressing. Pfizer and Moderna had multiple days/weeks long shutdowns that caused raging political disputes:
EU states express 'severe concern' as Pfizer temporarily reduces Covid-19 vaccine deliveries