according to recent reports in the United Kingdom.
The shift could be a cause of concern for the fall. As the main symptoms of the coronavirus change, people could spread the virus without realizing it.
“Many people are still using the government guidelines about symptoms, which are wrong,” Tim Spector, a professor of genetic epidemiology at King’s College London, told the Independent.
Prof. Spector cofounded the COVID ZOE app, which is part of the world’s largest COVID-19 study. Throughout the pandemic, researchers have used data from the app to track changes in symptoms.
“At the moment, COVID starts in two-thirds of people with a sore throat,” he said. “Fever and loss of smell are really rare now, so many old people may not think they’ve got COVID. They’d say it’s a cold and not be tested.”
COVID-19 infections in the United Kingdom increased 14% at the end of September, according to data from the U.K.’s Office for National Statistics. More than 1.1 million people tested positive during the week ending Sept. 20, up from 927,000 cases the week before. The numbers continue to increase in England and Wales, with an uncertain trend in Northern Ireland and Scotland.
The fall wave of infections has likely arrived in the United Kingdom, Prof. Spector told the Independent. Omicron variants continue to evolve and are escaping immunity from previous infection and vaccination, which he expects to continue into the winter.
But with reduced testing and surveillance of new variants, public health experts have voiced concerns about tracking the latest variants and COVID-19 trends.
“We can only detect variants or know what’s coming by doing sequencing from PCR testing, and that’s not going on anywhere near the extent it was a year ago,” Lawrence Young, a professor of virology at the University of Warwick, Coventry, England, told the Independent.
“People are going to get various infections over the winter but won’t know what they are because free tests aren’t available,” he said. “It’s going to be a problem.”
COVID-19 cases are also increasing across Europe, which could mark the first regional spike since the BA.5 wave, according to the latest data from the European CDC. (In the past, increases in Europe have signaled a trend to come in other regions.)
People aged 65 and older have been hit the hardest, the data shows, with cases rising 9% from the previous week. Hospitalizations remain stable for now, although 14 of 27 countries in the European region have noted an upward trend.
“Changes in population mixing following the summer break are likely to be the main driver of these increases, with no indication of changes in the distribution of circulating variants,” the European CDC said.
For now, most COVID-19 numbers are still falling in the United States, according to a weekly CDC update published Sept. 30. About 47,000 cases are being reported each day, marking a 13% decrease from the week before. Hospitalizations dropped 7%, and deaths dropped 6%.
At the same time, test positivity rose slightly last week, from 9.6% to 9.8%. Wastewater surveillance indicates that 53% of sites in the United States reported a decrease in virus levels, while 41% reported an increase last week.
The CDC encouraged people to get the updated Omicron-targeted booster shot for the fall. About 7.5 million Americans have received the updated vaccine. Half of the eligible population in the United States hasn’t received any booster dose yet.
“Bivalent boosters help restore protection that might have gone down since your last dose – and they also give extra protection for you and those around you against all lineages of the Omicron variant,” the CDC wrote. “The more people who stay up to date on vaccinations, the better chance we have of avoiding a possible surge in COVID-19 illness later this fall and winter.”
A version of this article first appeared on WebMD.com.