As Britain enjoyed a summertime lull in COVID-19 cases, the nation's attention turned to the end of pandemic-related restrictions and holidays in the sun.
But scientists are warning the public not to be complacent, saying high levels of infection in the community are likely to lead to another spike in cases this fall.
The reason for their pessimism is the delta variant of COVID-19, now dominant throughout the UK. Vaccines are less effective against this more transmissible variant, meaning Britain needs to achieve a much higher level of vaccination if it hopes to control the disease. About 60% of the UK population has been fully vaccinated.
“If you're going to rely on the vaccines, OK, then vaccinate everybody,” said Ravi Gupta, a University of Cambridge professor who did some of the pioneering studies on the delta variant. “But they've done a half vaccination job and then they've opened everything up. And this is a recipe for...Things not going well in the next few months.”
Despite an early summer surge in COVID-19 infections, the government on July 19 removed most remaining restrictions on social and business interactions. Prime Minister Boris Johnson trumpeted the moment as “Freedom Day", saying Britain's successful vaccination programme meant people were much less likely to get seriously ill or die from COVID-19.
But after a drop in confirmed new infections following July 19, cases have plateaued at an average of around 25,000 a day, more than 10 times higher than in early May. The seven-day average for coronavirus-related hospital admissions is about eight times higher than in May and deaths are 15 times higher.
All of the figures remain well below their winter peaks, when more than 60,000 people a day were testing positive for the disease.
Professor Julian Tang, an expert in respiratory diseases at the University of Leicester, is concerned infection levels in the community may actually be higher than the figures suggest.
“Human factors” — such as a drop in testing now that school is out and people who avoid getting tested because they don't want to miss out on their summer vacations — may mean that new infections are being undercounted and will rise rapidly in September, Tang said.
He thinks part of the problem is the government's reduced emphasis on social distancing measures since the end of lockdown.
“The virus is not going to go away unless you vaccinate everybody, including the children,” Tang said.
“So I think that there's too much optimistic, over-confident messaging and people get the wrong idea that you can go out and do everything — don't wear your mask, go and have a barbecue, have fun indoors. But then when you want to pull back from that, people don't want to do it because they've had that taste of freedom and they don't trust you anymore,” he said.
Health Secretary Sajid Javid said Tuesday that the vaccine rollout had created a “wall of defence” that has “massively reduced” hospitalizations and deaths from COVID-19. The government is now considering offering booster shots to the most vulnerable groups beginning in early September.
While Britain has achieved relatively high levels of vaccination compared to other countries, the shots haven't been delivered evenly throughout society.
The UK initially targeted older people and others who were particularly vulnerable to COVID-19. As a result, over 90% of people over 60 have received at least one dose of vaccine, compared with less than 65% for adults aged 18 to 35.
Britain last week expanded the programme to 16- and 17-year-olds. Government advisers are still considering whether to extend it to younger children.
The government may be forced to act because the delta variant has reduced the likelihood that Britain will ever be able to achieve “herd immunity", the point at which enough people are resistant to the disease — either through vaccination or previous exposure — to prevent it from spreading through the population.
Because the delta variant can infect people who have already been vaccinated, anyone who is unvaccinated is likely to, at some point, come into contact with the virus, Professor Andrew Pollard, director of the Oxford Vaccine Group, told lawmakers this week.
That means the vaccines may slow transmission of the disease, but they cannot stop it completely, he said.
“We know very clearly with coronavirus that this current variant, the delta variant, will still infect people who have been vaccinated and that does mean that anyone who's still unvaccinated, at some point, will meet the virus,” Pollard said.
He said while vaccines might “slow the process” of transmission, they currently cannot stop the spread completely.
“I think we are in a situation here with this current variant where herd immunity is not a possibility because it still infects vaccinated individuals," Pollard said. “And I suspect that what the virus will throw up next is a variant which is, perhaps, even better at transmitting in vaccinated populations."
That means Britain must learn to live with COVID-19, adjusting to a situation where the virus is always present, he said.
All of which means it's not time to celebrate Britain's victory over COVID-19, said Gupta, a professor of clinical microbiology at the Cambridge Institute of Therapeutic Immunology and Infectious Disease.
“We are going to see a resurgence in September of similar proportions to what we've just seen, if not worse. I think," he said. “That's why all this optimism is just misplaced right now.”