People who have received two doses of vaccine have a lower, but still appreciable, risk of becoming infected with the delta variant in the home compared with people who are unvaccinated. The authors stress that vaccination also reduces the risk of severe illness, hospitalisation and death from COVID-19.
The analysis found that around 25% of vaccinated household contacts tested positive for COVID-19 compared with roughly 38% of unvaccinated household contacts.
Fully vaccinated people cleared the infection more quickly than those who are unvaccinated, but their peak viral load – the greatest amount of SARS-CoV-2 virus found in their nose and throat – was similar to that seen in unvaccinated people, which may explain why they can still readily pass on the virus in household settings.