Respiratory illnesses are increasing across the U.S. as the holiday season brings more gatherings.

Health experts say influenza cases are climbing quickly. Three influenza viruses are circulating, with a new variant called subclade K driving most infections. “We’re seeing a lot of influenza cases increasing across the country,” said Andrew Pekosz with Johns Hopkins Bloomberg School of Public Health. He expects the trend to continue into the new year.

COVID-19 cases remain far below prior years, and RSV levels are also low. Pekosz says two strong RSV seasons combined with new vaccines may be helping reduce case numbers.

Vaccination is still the best way to prevent severe illness. “It is certainly not too late, especially as we’re thinking about holiday gatherings and travel,” Pekosz said.