COVID-19: Новости
30 April — One vaccine dose can nearly halve transmission risk
A single dose of the COVID-19 vaccine made by either Pfizer or AstraZeneca cuts a person’s risk of transmitting SARS-CoV-2 to their closest contacts by as much as half, according to an analysis of more than 365,000 households in the United Kingdom.
Although the vaccines have been shown to reduce COVID-19 symptoms and serious illness, their ability to prevent coronavirus transmission has been unclear. Kevin Dunbar, Gavin Dabrera and their colleagues at Public Health England in London looked for cases in which someone became infected with SARS-CoV-2 after receiving a dose of either vaccine (R. J. Harris et al. Preprint at Knowledge Hub https://go.nature.com/3e3iu1i; 2021). They then assessed how often those individuals transmitted the virus to household contacts.
The team found that people who had been vaccinated for at least 21 days could still test positive for the virus. But viral transmission from these individuals to others in their households was 40–50% lower than transmission in households in which the first person to test positive had not been vaccinated. Results for the two vaccines were similar. The findings have not yet been peer reviewed.