This flu season will likely peak in February and could be a mild one, according to a new model that aims to forecast the flu in the United States this winter.
The model uses information from past flu seasons, along with a mathematical representation of how influenza spreads through a population and the latest data on the current flu season to predict how seasonal flu will pan out in the coming months.
According to the new model, there's a less than 1 percent chance that the flu season will peak before January in most of the country, and a less than 20 percent chance that it will peak in January. On the other hand, there's a 57 percent chance that flu season will peak in February. That would be relatively late — the last three flu seasons have all peaked in December, said Dave Osthus, a researcher at Los Alamos National Laboratory who leads the flu forecast project.
The new model also predicts that this flu season will be mild, meaning there will be fewer flu cases than in a typical flu season.
The main reason for this prediction is that "historically, earlier-peaking flu seasons have tended to be more intense... [and] later-peaking seasons tend to be more mild," Osthus told Live Science.
But Osthus cautioned that there is still a lot that scientists don't know about predicting flu seasons — factors such as holiday travel and the rate at which people get flu shots could change the predictions. The researchers plan to update their predictions every two weeks during the 2015-2016 flu season and, at the end of the flu season, assess how well their model did, Osthus said.
The researchers will also continue to tweak their model to improve the predictions. For example, they plan to update the model to take into account how well the flu shot matches the strains of flu in circulation. The model will also incorporate Wikipedia searches for flu, which has been shown in previous research to help predict flu outbreaks.
Dr. Amesh Adalja, an infectious-disease specialist and a senior associate at the University of Pittsburgh Medical Center's Center for Health Security, who was not involved with the study, said that predictions for flu season can help people plan for the coming season. For example, a later start to flu season means there is more time for people to get vaccinated before flu activity picks up.
"A prediction [of a late flu season] could sway somebody that's been delaying" vaccination, Adalja said.
However, Adalja said that mild flu seasons can still cause a substantial number of illnesses. "Even a mild season of influenza is still a substantial burden," Adalja said. "Every season … kills thousands of Americans."
Osthus agreed. "Even though we're anticipating a milder flu season, we still highly recommend that everyone go and get their flu shot," Osthus said.
He also noted that the term "mild season" refers to how many people get sick with the illness, and not how severe the flu will be for an individual person.