Vaccine effectiveness against referral to hospital after SARS-CoV-2 infection in St. Petersburg, Russia, during the Delta variant surge: a test-negative case-control study

New research by @AntonBarchuk et al. Real world study on #vaccine efficacy against hospital admission after SARS-CoV-2 infection in St. Petersburg, Russia. Protection is probably mediated through vaccine efficacy against lung injury associated with #COVID.