A small-scale study on 113 healthcare workers who had received at least one vaccine dose at a private hospital in Delhi found that 18 tested positive for Covid but all except one had mild symptoms. Of the 113 in the study, 107 had received the second dose of the vaccine.
Taken in percentage form, the study found that breakthrough infections — Covid infection in vaccinated individuals — occurred in 15.9 per cent (18 persons) of the vaccinated individuals and 95 per cent had mild symptoms. Of these, 17 incurred the infection after the second dose. According to the study, of the breakthrough infections in 18 persons, 17 incurred the infection after the second dose. These 17 had got their second dose after a mean of 34.8 days following the first jab.