WebMD – Fully vaccinated people still face considerable risks for contracting COVID-19, according to a new study published Wednesday by Imperial College London.

At the same time, they were three times less likely to test positive for the coronavirus than unvaccinated people.

Paul Elliott, director of the survey program and a professor at Imperial’s School of Public Health, said in a statement:

“These findings confirm our previous data showing that both doses of a vaccine offer good protection against getting infected.

“However, we can also see that there is still a risk of infection, as no vaccine is 100% effective, and we know that some double-vaccinated people can still become ill from the virus.

“So even with the easing of restrictions, we should still act with caution to help protect one another and curb the rate of infections.”

The latest findings, which come from an ongoing study of the U.K. population, were based on more than 98,000 swabs taken between June 24 and July 12 … READ MORE. 

Infections in vaccinated people

IMPERIAL COLLEGE OF LONDON – For this latest round of the REACT study, 98,233 people swabbed themselves at home and their samples were analysed by PCR testing.

527 of these were positive, giving an overall prevalence of 0.63%. 254 of these were successfully analysed in the lab to determine their origins, 100% of which were the Delta variant. In the previous round, the figure was just under 80% for Delta with the remaining Alpha.

People who were unvaccinated had a three-fold higher prevalence than those who had received both doses of a vaccine, at 1.21% compared to 0.40%.

“We need to better understand how infectious fully vaccinated people who become infected are.” – Prof Steven Riley, School of Public Health

However both of these represent more than a five-fold increase compared to the previous round (0.24%, 0.07%, respectively).

Based on these data, the researchers estimate that fully vaccinated people in this testing round had between around 50% to 60% reduced risk of infection, including asymptomatic infection, compared to unvaccinated people.

In addition, double vaccinated people were less likely than unvaccinated people to test positive after coming into contact with someone who had COVID-19 (3.84% vs 7.23%).

Professor Steven Riley, Professor of Infectious Disease Dynamics at Imperial, said:

“The Delta variant is known to be highly infectious, and as a result we can see from our data and others’ that breakthrough infections are happening in fully vaccinated people.

“We need to better understand how infectious fully vaccinated people who become infected are, as this will help to better predict the situation in the coming months, and our findings are contributing to a more comprehensive picture of this.” READ MORE.