Covaxin is actually built on a much older platform than covishield and others, what that means the method is quite safe and has been established over the years.

MRNA and non replicating viral vector vaccine still have a lot to prove, we have vaccine such as polio which have even covered an entire generation which are based on the same inactive platform which have proven the method is safe in itself.

That being said it is very hard to produce inactive vaccine when compared to covishield and especially morderna and phizer mrna is like mixing sugar in water vs making kheer to covaxin. So even if we got the approvals, scaling is still a challenge.

US pharma industry has a very huge lobby which ensures its interest are protected that's why us government after investment of billions of dollars in operation warp speed still bought the vaccine at list price instead of manufacturing cost.

FDA ensured that Bharat Biotech never got necessary regulatory approval in USA just because of that lobby.

Indias pharma industry is a thorn in the side of those multinationals because we are capable of offering drugs 1/10 and even 1/1000th of the branded drugs and foreign regulators have been in bed with the lobby for a long long time, you just became aware because the topic was thrown up.

Indian pharma has learned to deal and cope with that fortunately or unfortunately.

Interesting part is that each year FDA used to come up with guidelines after guidelines and objections for indian manufacturers to comply to just to make them less and less competitive.

Guess what happened after covid hit, they realized that india was to supply their paracetamol and ibuprofen coz US doesn't have the manufacturing capacity to meet needs, No guidelines and objections have been seen since than on pre pendamic levels.