Health experts warn that another winter surge is possible, with cases already increasing in Europe and researchers on the lookout for new strains of the virus.
The increase occurs just as many Americans traveling overseas will have less immunity against the prevalent omicron variant due to low vaccination rates for the new bivalent booster. Only 4% of Americans who are eligible had received the new shot as of early October.
Related: When will U.S. allow unvaccinated travelers?
Where is the coronavirus spreading around the world?
There are indications of a spike in Europe, which could portend another winter wave in the US. Cases have increased by 104 percent in Portugal and by 42 percent in Switzerland over the past week. The virus has also increased in Germany, France, Italy, and Austria.
The European Center for Disease Prevention and Control and the World Health Organization issued a joint warning on Wednesday, predicting that a new covid wave is likely to hit Europe along with a rebound of the flu.
In its most recent weekly report, the ECDC said that across the continent, “widespread increases were being observed in all indicators,” including cases, hospitalizations, and fatalities.
Additionally, the number of instances of covid has increased in regions of Asia, including South Korea, Taiwan, and Japan, all of which have recently loosened their travel restrictions.
The Ministry of Health announced on Saturday that an omicron subvariant known as XBB increased from a 22 percent share of local cases to 54 percent over the course of a week in Singapore, where the average number of daily reported cases has increased by 44 percent over the past week.
According to Sanjana Ravi, a visiting assistant scientist at the Johns Hopkins Center for Health Security at the Bloomberg School of Public Health, when instances rise in Europe, it’s frequently “just a matter of weeks or months” before a surge follows in the United States.
“We saw that with the delta variant. We saw that with the omicron variant,” Ravi said. “I think it’s safe to take precautions considering that we’re starting to see those numbers go up again in Europe now.”