Men gathering to watch football may be a potential reason why women were nearly a third less likely than them to test positive for coronavirus, experts have suggested.
Interim findings covering June 24 to July 5 from Imperial College London and Ipsos Mori show infections have quadrupled since the last React-1 study, which took place from May 20 to June.
One in 170 people is infected and there is a recent doubling time of six days, the data suggests.
This round was the first time a notable difference was seen between the number of men and women testing positive for the virus, researchers say.
Different things could be affecting it. I think the degree to which men and women are socialising, is likely to be responsibleProfessor Steven Riley
Professor Paul Elliott, director of the React programme from Imperial’s School of Public Health, said: “We have noticed in the current round that the prevalence is higher in men than women – around 0.7% in men and around point 0.5% women.
“And women have therefore something like a 30% reduced odds of testing positive in our study, once we’ve adjusted for other variables.”
Asked why this might be the case, Steven Riley, professor of infectious disease dynamics at Imperial said fluctuations in transmission are likely to be caused by changes in social mixing.
He added: “And there’s lots of evidence that mixing inside is more likely to result in transmission than mixing outside.
“If I had to speculate about the impact of the Euros, I would first think about the possible impact- much much more broadly than around when we are around London – I would think about the increased probability that people are mixing inside more frequently than they otherwise would.
“So my first thought wouldn’t immediately be to the stadium and the immediate surrounds it would, it would be about the more general behaviour of the population, but we don’t have results that speak to that directly in this study.”
Prof Riley further said: “Different things could be affecting it. I think the degree to which men and women are socialising, is likely to be responsible.
“And then because of the timing of that, then it could be that watching football is resulting in men having more social activity than usual.”
The study also found that infection rates for double vaccinated under-65s are three times lower than in unvaccinated under-65s, demonstrating the impact of the vaccination rollout
Cases are expected to continue rising as restrictions are eased and people are urged to remain cautious and exercise personal responsibility.
The latest data show infections in England have increased fourfold from 0.15% to 0.59% since the last React-1 report.
There has been a continued exponential growth in prevalence with an average doubling time of 15 days between round 12 and round 13.
However, during the first half of round 13 only, there was a doubling time of 6.1 days with a corresponding R value of 1.87, the data suggests.
While there has been an increase in all age groups under the age of 75 years, the highest prevalence is for 13 to 17-year-olds at 1.33% and 18 to 24-year-olds at 1.40%.
The data indicates that infections have increased in all regions – with the largest increase in London, where prevalence has increased more than eightfold from 0.13% in round 12 to 1.08% in round 13.
However, prevalence is increasing to a lesser extent among those vaccinated, rising from 0.06% in people aged 65 and above who reported receiving two doses in round 12, to 0.24% in the same group in round 13.
Health Secretary Sajid Javid said: “As we unlock society and learn to live with Covid-19, we will inevitably see cases rise significantly over coming weeks.
“But today’s findings show that infection rates are three times lower for those who have had two vaccine doses.
“It is more important than ever to get that life-saving second jab so we can continue to weaken the link between cases, hospitalisations and deaths and build a wall of defence against the virus.
“As we move from regulations to guidance and get back to our everyday lives, see our loved ones and return to work, it is vital people practice good sense and take personal responsibility for their own health and those around them.”
Prof Elliott said: “In spite of the successful rollout of the vaccination programme, we are still seeing rapid growth in infections, especially among younger people.
“However, it is encouraging to see lower infection prevalence in people who have had both doses of a vaccine.
“It is therefore essential that as many people as possible take up both vaccine doses when offered.”