Flu season has arrived weeks earlier than usual in the United States, and health officials are urging people to get vaccinated now rather than waiting for winter. The Centers for Disease Control and Prevention estimates that flu cases are likely rising in 44 states, based on recently released data. National activity remains low overall, but cities and states are reporting infection numbers they would normally expect in November or December.
Neil Maniar, director of Northeastern University's master of public health program, said the early cases point to a difficult winter ahead. "It's hard to tell how bad the flu season will be. But if these early cases and outbreaks are an indication, and if we look at the past few years, it's going to be a pretty tough flu season," Maniar said. "So, now is a good time to get vaccinated."
Vaccination does not stop every flu infection. Health officials say it can still reduce the risk of hospitalisation and lessen illness severity. Common flu symptoms include fever, cough, sore throat, a runny nose, body aches and tiredness. The flu can also lead to pneumonia, respiratory failure and heart problems in some patients.
Flu season numbers so far
The CDC estimated 45,000 flu related deaths and 710,000 flu related hospitalisations during the 2024-2025 season. Those figures show why early rises draw attention even when current national activity is described as low. An early flu season gives the virus more weeks to spread before vaccination coverage catches up, and hospitals watch admission trends closely in the opening weeks.
In New York, the state Department of Health reported in mid-October that flu cases had increased by 19 percent, or about 553 cases, from the prior week. Hospitalisations linked to flu in the state rose from 199 to 233 in the same period. During the 2025-2026 flu season, nearly 27,000 New Yorkers were hospitalised with the flu and 600 died, according to state figures cited in the Northeastern report.
New York State Health Commissioner James McDonald told reporters that the number of state residents who had received a flu vaccine was significantly lower than the year before. "I don't read too much into that other than people just need to be reminded that it's the time of year to get your flu vaccine," McDonald said.
What the H1N1 mutation means
Brandon Dionne, a clinical professor at Northeastern University, said the amount of flu in the country is still relatively low. He added that researchers are keeping a watchful eye on the G155E mutation that emerged in an H1N1 influenza strain. It is too soon to pinpoint the cause, Dionne said.
Earlier CDC data reported elsewhere in October showed flu test positivity at 5.7 percent for the week ending October 17, up from less than 1 percent in the same week a year earlier. Influenza A H1N1 has driven most early cases, a change from last winter, when a different strain dominated. Researchers first flagged the G155E mutation in Seattle in September, and preliminary CDC data indicate antibodies from the current vaccine still recognise the circulating virus.
That point matters for flu season vaccination advice. If the vaccine still recognises the virus, a shot taken now can offer protection before cases climb further. Real world effectiveness data are expected to arrive in early December, according to Johns Hopkins researchers who spoke at an October 29 media briefing.
Flu season pressure on the West Coast
One of the hardest hit areas so far this flu season is the West Coast. Los Angeles County health officials recently announced the area's first two flu related deaths of the season. "These deaths are a sobering reminder that influenza can cause serious illness and even death," Dr. Muntu Davis, Los Angeles County health officer, said in a statement. "We strongly encourage everyone six months and older to get a flu vaccine as soon as possible," Davis said.
Cedars-Sinai Medical Center announced a dozen upcoming free flu clinics and health screenings in Los Angeles. Much of the effort is focused on children. The last two flu seasons resulted in an unusually high number of child deaths, and the vast majority were in unvaccinated children, according to the Northeastern report.
Maniar said vaccination remains an important public health measure, and creative messaging can help reach people who might otherwise put it off. "There's a real importance right now to make sure that as many people as possible get vaccinated and that we're reaching people in the right way and with the right information," Maniar said. Clinics, pharmacies and doctors offices remain the main places to get a shot in flu season, and officials say people should not wait for a local outbreak to act.