Effect of Vaccination on Transmission of SARS-CoV-2

Letter reports that vaccination of health care workers employed March 2020 to November 2020 in Scotland was associated with a decrease in documented cases of Covid-19 among members of their households, providing empirical evidence that vaccination may reduce transmission

SPS commentary:

Data were analysed for 194,362 household members of 144,525 health care workers. Cases of Covid-19 were less common among household members of vaccinated health care workers during the period beginning 14 days after the first dose than during the unvaccinated period before the first dose (event rate per 100 person-years, 9.40 before the first dose and 5.93 beginning 14 days after the first dose). After the health care worker’s second dose, the rate in household members was lower still (2.98 cases per 100 person-years).

New England Journal of Medicine