The holidays are here, and so is respiratory illness season, with three influenza viruses circulating in the U.S.

The new variant, subclade K, is driving most infections.

Andrew Pekosh with Johns Hopkins Bloomberg School of Public Health says the U.S. will likely see a pretty severe flu season.

“We’re seeing a lot of influenza cases increasing across the country, and that’s a trend that we’re sure will continue into the new year,” he said.

Some states are already seeing high levels of the virus, but Pekosh says the new variant makes it likely for every state to have high flu case numbers in the next two to three months.

“Whether we’re simply seeing more cases because this subclade K influenza virus is evading immunity, and therefore more people are susceptible to infection, or if it’s really causing more severe disease on a case-by-case basis,” he said.

Meanwhile, experts say numbers of cases of COVID-19 are nowhere near what we’ve seen in prior years, but this virus sometimes increases mid-winter, and RSV levels have also been low.

“It’s not clear exactly why, but two strong RSV seasons combined with new RSV vaccines and treatments may all be contributing to that reduced case number,” said Pekosh.

Pekosh said vaccination is still the best way to protect against severe disease for all of these respiratory viruses. He says the flu vaccine is a good match for two strains of the virus, but may evade some, but not all, vaccine-induced protection.

“It is certainly not too late, especially as we’re thinking about holiday gatherings and travel,” he said.

According to the CDC, the first full week after the Thanksgiving holiday, doctor’s visits for symptoms including fever plus a cough or sore throat rose to 3.2%.

Copyright 2025 by WPLG Local10.com - All rights reserved.