Vaccinated just as likely to spread delta variant within household as unvaccinated: study

The study comes as the United States has started to see a nationwide decline in COVID-19 cases, though it remains unclear if this decline will be permanent or if a resurgence of cases could come back in the winter. (Getty Images)

by: Caroline Vakil, The Hill, Nexstar Media Wire

Posted: Oct 29, 2021 / 09:49 PM MDT

Updated: Oct 29, 2021 / 09:50 PM MDT

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

(The Hill) – People who have received COVID-19 vaccinations are able to spread the delta variant within their household, despite their vaccination status, just as easily as unvaccinated individuals, a new study published on Friday shows.

According to the study, published in The Lancet Infectious Diseases journal, people who contracted COVID-19 had a similar viral load regardless of whether they had been vaccinated. The study further found that 25% of vaccinated household contacts contracted COVID-19, while 38% of unvaccinated individuals were diagnosed with the disease.

Researchers examined 621 symptomatic participants in the United Kingdom over a year.

“Although vaccines remain highly effective at preventing severe disease and deaths from COVID-19, our findings suggest that vaccination is not sufficient to prevent transmission of the delta variant in household settings with prolonged exposures,” the study said.

In contrast, researchers noted that the vaccination was more effective at curbing transmission of the alpha variant within the household, at between 40-50%.

“Increasing population immunity via booster programmes and vaccination of teenagers will help to increase the currently limited effect of vaccination on transmission, but our analysis suggests that direct protection of individuals at risk of severe outcomes, via vaccination and non-pharmacological interventions, will remain central to containing the burden of disease caused by the delta variant,” the researchers wrote.

The study comes as the U.S. has started to see a nationwide decline in COVID-19 cases, although it remains unclear if this decline will be permanent or if a resurgence of cases could come back in the winter.

Earlier this month, former Food and Drug Administration Commissioner Scott Gottlieb predicted that the “pandemic phase” of the COVID-19 will end with the approval of antiviral pills and COVID-19 vaccines for children and that the U.S. would soon transition into an “endemic” phase instead as Americans learn to live with the virus.