A medical worker who was vaccinated against the coronavirus Sputnik V in Russia's Ulyanovsk region has tested positive for COVID-19.According to Qadin.Net, this was reported by Interfax.According to the agency, this was the first case during the observation of medical workers vaccinated against coronavirus. The cause of the infection was the lack of immunity to the coronavirus within a week after the first injection.It is noted that immunity can be formed only after the second injection of the vaccine.