Study indicates vaccines slow down COVID-19 transmission

A study of almost 100,000 volunteers in England has revealed the major impact that novel coronavirus vaccination has in stopping transmission of the Delta virus, the form of the virus that is now dominating infection across the country.

The survey, conducted by Imperial College London, looked at 98,000 cases and found that vaccination halved transmission and was also 60 percent effective when it came to preventing symptoms.

Because of the Delta variant's dominance, it was the only strain of the virus looked at in the study, which covered both the Pfizer and AstraZeneca vaccines, but did not specify the figures for each.

"Vaccination remains highly effective against Delta," said Paul Elliott, co-leader of the project.

Tom Wingfield, senior clinical lecturer at Liverpool School of Tropical Medicine, told the Financial Times that the results, coming after other studies, gave a more optimistic outlook for the future.

"The findings, when coupled with other studies demonstrating the impact of coronavirus vaccines on reducing hospitalization and death from COVID-19, are encouraging," he said. "However, (they) also serve as a reminder that, even with extremely high vaccine coverage, we are highly likely to have a further wave of infections in the autumn (fall)."

Speaking on the BBC Radio 4 Today program, Imperial College study leader Elliot said that overall, the United Kingdom's handling of the pandemic was "going in the right direction" but the big challenge was ensuring that this progress was not lost later in the year-with continued vaccination key to making this happen.

"We think at the moment things are going in the right direction now as schools are closed, people are on holiday and people are mixing outdoors more," he said.

"The big issue is what's going to happen in the autumn when people go back to school and there's more indoor mixing, people go back to work. So it's really, really important, in our view, that as many people as possible get double vaccinated before the autumn period. That will increase the downward pressure on the virus."

He also highlighted that the highest recent infection levels were among unvaccinated people up to the age of 24. "Anything we can do to reduce transmission in that group would be helpful," he added.

When asked if it was advisable for children to be vaccinated, he said: "Although it is true that most children will not be badly affected by the virus, there is a proportion that will go on to have longer-term illness.

The government has indicated that the 16- to 17-year-old age bracket is likely to be the next one to be offered vaccination.

Universities minister Michelle Donelan told Sky News the government was waiting for an announcement from the Joint Committee on Vaccine and Immuniation, or JCVI.

"At every stage throughout the pandemic, we've adopted their advice on this," she said.

"They are the experts, of course, when we're determining the vaccine rollout and we'll await their imminent announcement shortly."

In July the JCVI said it was still assessing the benefits and risks of vaccinating youngsters, as generally they tend to be less severely affected by the virus.

However, given the data showing the impact vaccination has on transmission, it now looks likely that the committee will endorse it.

If it does choose to go ahead with widening the program, around 1.4 million teenagers would be eligible.