If (big if) the Russian or Chinese vaccines had been approved by the MHRA and that was the one I was offered, I would take it. Because I trust the scientists in the MHRA to interrogate the evidence and only approve it if they believe it to be safe and effective.
I also don't care much whether I get Pfizer, Moderna, Oxford, or Old Uncle Tom Cobbley's patent vaccine - as long as it has been signed off by the MHRA and is thought, on the basis of the available evidence, to be the one best suited to me. Basically, whichever MHRA-approved vaccine I am offered, I will take.
Because, at 56, severely obese and with diabetes, I don't want to die of Covid, or develop long Covid, and I also want to be able to hug my Mum, go to concerts and lounge around all day in bookshops/coffee shops like I used to do on my day off before all this lot happened.
Biontech developer say that it seems to have:
50% efficacy in preventing the virus and
90% efficacy in curing the virus.
If you're referring to the same interview I saw, then that's not what he said. What he said was, we have demonstrated it is 90% effective in preventing people from developing disease. We don't know how effective it is in preventing people from transmitting the virus, but if, as a guess, it was only 50% effective, that would still help to suppress the pandemic.
I'll see if I can find the quote and link it.