The university announced this week that federal public health officials are investigating a “major and sudden” outbreak of influenza among University of Michigan students.
Since October, there have been 528 cases of the flu on campus in Ann Arbor, the vast majority — 77 percent — occurring in students who haven’t been vaccinated against the flu. The university said the spread of the disease has accelerated over the past several weeks.
Experts from the federal Centers for Disease Control and Prevention were on campus this week to help university officials and local health authorities analyze the outbreak and assess the effectiveness of this year’s flu vaccines.
Emily Martin, an assistant professor of epidemiology in the university’s School of Public Health who is helping with the investigation, said the current case number is large, especially compared to recent years. She added that the university may identify more cases of influenza this year because students have been seeking tests for symptoms that overlap with Covid-19.
“It’s a great opportunity to get a good early indication of the efficacy of the vaccine right now, what strains are in circulation, and what you can expect for the rest of the country,” said Dr. Martin.
Nationwide, the flu incidence remains low, but the CDC said this week it had received reports of the disease spreading among college-age adults. Outbreaks such as the one at the University of Michigan represent the first significant activity of this year’s flu season, the agency said in a statement. The flu season generally begins in October and can last through May, the agency said.
Agency spokeswoman Kate Grosich said the outbreak at the University of Michigan is the only on-campus investigation the CDC is currently involved in.
Dr Martin said the university and local health authorities had enlisted the agency’s help, adding that the investigation was a joint effort.
In Michigan, 2.2 million doses of the flu vaccine have been administered this year, a number that represents about 22 percent of the state’s population, according to state data. Vaccination rates in each age group have lagged behind rates for the past two years.
The data shows Washtenaw County, which includes Ann Arbor, vaccinates one in three residents against the flu.
An estimated 43.2 million flu vaccines were administered nationally in pharmacies and doctors’ offices to people 18 and older by the end of October, Grusich said. She said about 62.4 million doses were administered in the same time period last year.
Experts said last year’s flu season was mild compared to previous years’ season, as the precautions people took to slow the spread of the coronavirus, including masking and social distancing, helped prevent the spread of the flu.
Dr Martin said the university was hearing from students who were confused about how the flu and Covid-19 vaccines would interact. She encouraged the students to get the two vaccines, stressing that they have distinct benefits.
“One does not replace the other,” she said.
A recent survey by the National Foundation for Infectious Diseases found that four out of 10 Americans are unsure about the flu vaccine or never plan to get it. About a third of 1,000 people surveyed reported having more concerns about contracting Covid-19 than the flu.
But experts have warned that this year could be different and little is known about the interaction of Covid-19 and influenza. The Centers for Disease Control and Prevention (CDC) recommends that everyone 6 months of age or older get a flu shot.