Early clinical trials have been completed on a second Russian vaccine, a health official said Wednesday, moving it closer to registration under the Russian approach of approving vaccines for emergency use before beginning late-stage trials to determine whether they are effective.
Early trials provide information about safety, though rare side effects may go undetected until much larger late-stage trials are conducted. The later trials, known as Phase 3, are the only means of determining whether a vaccine actually protects against the coronavirus.
Russia registered its first Covid-19 vaccine — one based on common cold viruses — in August, and is now offering a small number of doses outside of trials to people at elevated risk of infection, like health care workers. Western vaccine experts criticized the Russian approach as potentially dangerous.
Anna Papova, the head of Rospotrebnadzor, a Russian agency regulating health care, said on Wednesday that researchers had completed early clinical trials of a different vaccine, based on proteins that mimic those in the coronavirus.