Influenza has stormed into Massachusetts weeks earlier than normal, sickening people at rates typically not seen before January, according to data released Friday.
The weekly flu report from the Massachusetts Department of Public Health shows a striking rise in flu-related hospitalizations and flu-like illness in the week of Nov. 27 through Dec. 3. Children younger than 4 and adults 65 and older have the highest rates of hospitalization.
Meanwhile, the percentage of Massachusetts residents who were vaccinated against flu at this time of year — 38 percent — is similar to previous years. The problem is, there’s much more flu circulating now than usual in early December, prompting public health officials to urge people to get their shots as soon as possible.
Flu season typically runs from October to May, peaking in December through February. The spike in flu cases comes just as people return from Thanksgiving holiday travel. It also comes as cases of respiratory syncytial virus, or RSV — another common virus that arrived early and that can make children very ill — is starting to plateau or decline, and COVID-19 continues to spread.
“At this moment we’re seeing a lot of cases earlier than we normally would,” said Dr. Richard Malley, an infectious diseases specialist at Boston Children’s Hospital. But he noted that it’s too early to know whether the total number of cases will be higher at the end of the season, or whether there will be more severe illness.
“Because we don’t know how long this is going to go for, it makes sense to get vaccinated,” he said.
The state’s data show that 3 percent of hospitalizations last week were associated with influenza, a percentage not seen until late January in the 2019-2020 flu season, and higher than throughout the two most recent flu seasons. Likewise, doctor’s visits for influenza-like illnesses reached nearly 6 percent last week. In the 2019-2020 flu season, it took until early February for such visits to reach that percentage, and it was lower throughout the 2021-2022 and 2020-2021 flu seasons.
Although no one knows for sure why flu came early, Malley said, it may result from the fact that pandemic precautions prevented young children from being exposed to flu earlier in their lives, leaving them especially susceptible this year.
“All of a sudden you’re having a very large population of immunologically naive children seeing flu for the first time,” he said. With less immunity, they are more likely to catch the flu and also to spread it.
“It’s an unprecedented situation,” Malley said. “We have changed the epidemiology of this virus by changing our behavior.”
While RSV causes severe illness mostly in tiny babies, the flu, for unknown reasons, can also affect older children. “Some kids who are otherwise healthy seem to handle a flu case not as well as you’d expect for their age,” Malley said.
“Many of the same principles that we applied before for COVID, we should apply for this,” he added, especially wearing masks, isolating when sick, and getting vaccinated.
Flu is much more likely than COVID to cause severe illness in children, said Dr. Wayne Altman, a family medicine doctor in Arlington. And it spreads quickly among children, who tend not to take precautions, he said.
“Most children are going to do fine with the flu,” said Altman, who is chair of family medicine at the Tufts University School of Medicine. “But there are some kids who can get dangerously sick with influenza, which is more than you might see in COVID.”
On Thursday, the Boston Public Health Commission issued an alert about the early flu epidemic, saying that the city has seen 1,784 influenza cases since Oct. 1, more than 700 cases of them within the previous week.
The commission also reported a spike in children being hospitalized with flu and said that 59 percent of reported flu cases occurred among children and adolescents younger than 18 years old.
Similar trends are happening nationwide. In a press briefing Monday, Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, said hospitalizations for flu are the highest seen at this time of year in a decade. So far this season, according to CDC estimates, there have been at least 13 million illnesses, 120,000 hospitalizations, and 7,300 deaths from flu. That includes 21 deaths among children.
Flu shots are recommended for everyone older than 6 months. As of Dec. 3, according to state data, 43 percent of those 6 months to 4 years and 37 percent of 5- to 12-year-olds had been vaccinated against the flu. That’s better than the 26 percent of people age 18 to 49. The highest percentage — 67 percent — was among those 65 and older.
Statewide, vaccination rates are lower among ethnic minorities, with only 26 percent of Black people and 22 percent of Hispanic people vaccinated so far, compared with 39 percent of white people. Rates of hospitalization with flu show similar trends: So far this year, 10 per 100,000 white people were hospitalized with the flu, compared with 16 per 100,000 Hispanic residents and 19 per 100,000 Black residents.
Attitudes toward flu vaccination fall into three categories, Altman said: Some people always get a flu shot; some awakened to the importance of vaccines during the pandemic and are now getting flu shots when they hadn’t in the past; and some have pandemic fatigue and aren’t getting the shot.
“I urge everyone to be safe this holiday season,” Dr. Bisola Ojikutu, commissioner of public health and executive director of the Boston Public Health Commission, said in a statement. “Stay home if you’re sick and call your doctor to ask about treatments for flu and COVID-19, in addition to staying up to date on vaccinations, wear a mask indoors to reduce your risk of illness.”
You can locate a flu shot provider by searching this government website: https://www.vaccines.gov/find-vaccines/