The Pfizer contract for the COVID-19 vaccine with Albania got leaked. In it they admit they don't know if the vaccine works (unknown efficacy), call the product aspirational with unknown side and long-term effects.

"Purchaser acknowledges...the long-term effects and efficacy of the Vaccine are not currently known and that there may be adverse effects of the Vaccine that are not currently known."
https://twitter.com/eh_den/status/1419678665655336971?s=19