Russia boasts that it’s about to become the first country to approve a Covid-19 vaccine, with mass vaccinations planned as early as October using shots that are yet to complete clinical trials — and scientists worldwide are sounding the alarm that the headlong rush could backfire, AP reported.

The experimental Covid-19 shots began first-in-human testing on a few dozen people less than two months ago, and there’s no published scientific evidence yet backing Russia’s late entry to the global vaccine race, much less explaining why it should be considered a front-runner.