The Delta COVID-19 variant can easily transmit from vaccinated people to their household members, said a recent UK study, although its researchers concluded that vaccinations and boosters are the way forward.
A year-long study from the Imperial College London published in The Lancet on Thursday found that the Delta variant is still highly transmissible within a vaccinated population.
“By carrying out repeated and frequent sampling from contacts of COVID-19 cases, we found that vaccinated people can contract and pass on infection within households, including to vaccinated household members,” Dr. Anika Singanayagam, co-lead author of the study, said in a statement.
The findings, Singanayagam added, provide some insight into why the Delta variant is “continuing to cause high COVID-19 case numbers … even in countries with high vaccination rates.”
An analysis found that the viral load declined most rapidly for those who were vaccinated with the Delta variant compared with those who are unvaccinated, according to the researchers.
But the peak levels of the CCP (Chinese Communist Party) virus, which causes COVID-19, in vaccinated people were similar to levels in unvaccinated people, they found, adding that it might be the reason why the Delta variant can spread despite vaccination.
Because the Delta variant can spread easily among vaccinated people, another researcher involved in the study, Dr. Ajit Lalvani, argued it is necessary for people to get the vaccine or boosters to reduce severe COVID-19 symptoms.
“We found that susceptibility to infection increased already within a few months after the second vaccine dose … so those offered a booster should get it promptly,” Lalvani said.
Their study, which surveyed 621 participants, found that of 205 household contacts of people who had the Delta infection, about 38 percent of household contacts who were not vaccinated tested positive, compared with 25 percent who tested positive among vaccinated household contacts.