I don't think the high number in India is due to a vaccine being ineffective. We've barely inoculated 15% of our population. How can we even comment on if vaccines are the issue considering all the other things that went on in the last 2 months?
A thing to consider with the Pfizer study is that the Indian dominant variant has just been genetically determined, very recently. Due to higher inoculation rates in the US, people catching covid itself is less, and the ones that are catching it now, seem to be catching the Indian variant, probably due to its higher virulence. So this study clearly isn't a real indicator of which is a better vaccine. It's a retrospective study that was done in haste to improve marketing gains. This is just marketing by Pharma companies. It's not like they, or any pharma company, can perform a prospective study to determine efficacy: that would involve giving them a vaccine and then sending them to a covid ward to catch the virus, and then determine the proportion of people that got sick. It's unethical, to say the least. No retrospective study can give indicators like the incidence of the disease, or the relative risk, etc; only a prospective study can do that. And it's also not like Pharma companies or government organizations like CDC don't know this information. Anyone with basic statistic skills can affirm this. It's all allowed to slide under the carpet, cos hey the stocks are rallying, so who cares?
No vaccine guarantees no infection. Only a very low exposure to the virus can assure that, which is possible by the same things being said from the beginning:
mask, social distance, and hand wash often, and last on the list is get vaccinated as soon as you can, with literally anything that's available.