New coronavirus cases have declined for six days in a row in Britain, a shift that is baffling scientists, many of whom predicted a powerful surge in cases after the government relaxed all but a handful of restrictions in England last week.
Few experts are willing to draw definitive conclusions from the downward trend, which could reflect transient factors like the school summer break, the end of the European soccer championships or fewer people getting tested for the virus.
But if sustained, the case numbers raise a tantalizing prospect that Prime Minister Boris Johnson bet correctly that the country could withstand a return to normalcy, even with the rapidly transmissible Delta variant widely circulating in the population. Even his own health secretary, Sajid Javid, predicted that cases could skyrocket to 100,000 a day before the country’s third wave of the pandemic ebbed.
The government has been careful not to declare victory too soon. Mr. Johnson emerged from self-isolation himself on Tuesday, after being in close contact with Mr. Javid, who tested positive for the virus on July 17.
“It is very, very important that we don’t allow ourselves to run away with premature conclusions about this,” the prime minister told reporters on Tuesday during a visit to a police station in Surrey, southwest of London. “People have got to remain very cautious, and that remains the approach of the government.”
On Monday, the government reported 24,950 new cases, down from a high of 54,674 on July 17. Hospital admissions and deaths are still up compared with a week ago, though both are typically lagging indicators. The Daily Telegraph reported, based on leaked data, that roughly half of all new Covid cases in people admitted to hospitals were in patients seeking care for other illnesses and found to be infected through routine testing.
That would be another encouraging sign, experts said, since it would suggest that many such people do not even realize that they have Covid — confirmation that the vaccines have weakened the link between infection and serious illness. Just over 70 percent of adults in Britain have received both doses of a vaccine.
In addition to the threat of soaring cases, Britain has also struggled with a cascade of people being notified, or “pinged,” by the National Health Service and told that they had been exposed to the virus and should quarantine themselves.
Scientists said it would take several more days to form definitive conclusions about the declining case numbers.