Thread by @fascinatorfun

Covishield is the is AstraZenica.
Covaxin is the Indian developed vaccine.

The AZ vaccine after the 2nd dose is strongly performing.
c5K cases after 15 million second doses.

Particularly good news as deployed in VERY high prevalence AND with the new 🇮🇳 variants prevalent

https://twitter.com/sailorrooscout/status/1384831760668692483

Covaxin seems to be performing well too with just 695 positives after 1.7 mill second doses

(that comma caught me out after 17. - I thought for a moment it was 17 million, but on closer look it is 1,737,178)

Given social distancing has not been strongly maintained v. promising

No one would wish the dreadful tsunami of cases and deaths we are seeing in India to be visited on anyone.

However there is no doubt that the vaccines are being rolled out and tested “in anger” in very hard conditions indeed.

Second dosing really does confer an advantage.

The Indian Expert Groups gave permission for the AZ vaccine dosing interval to be extended from four to six week.

It has now (from April 4th) given permission for the second dose to be given up to eight week after the first dose.

There is reason to believe that longer interval will provide a stronger second dose boost.

It would be good to have more granular data on the breakthrough cases. How long after the second dose (it takes a bit of time for the boost to boost!).

Symptomatic? Death?

I would like to see a breakdown of breakthroughs by state as well.

Delhi / Maharashtra has been returning 25-30% positivity in recent days.

If the breakthrough rate there is very low that would be super encouraging.

The other problem, without context, is that India’s hospitalisation data not worth a great deal as too many people cannot get a hospital bed.

Also we KNOW that Cause of Death data re Covid is highly likely to be grossly underestimated.

So context would be welcome - & necessary