An influenza epidemic at the University of Michigan has sickened more than 500 people since early October. Local health officials have now brought in help from the Centers for Disease Control and Prevention to investigate the issue, which may offer a preview of the flu season this winter. One important consideration is that a majority of the patients have so far been unvaccinated.
To date, 528 cases of influenza have been reported by the university since October 6, according to news communication of the university. Most of these cases have been diagnosed recently, however, with more than 300 reported last week alone. These cases have been linked to a frequently circulating subtype of influenza A known as H3N2.
The typical flu season in the United States can begin as early as September and last until April. But the uncharacteristic size and spread of this outbreak at this point in the year was enough to prompt Michigan officials to call the CDC.
“Although we often start to see some flu activity now, the magnitude of this outbreak is unusual,” Juan Luis Marquez, medical director of the Washtenaw County Health Department, is quoted at the university as saying.
Last winter, the seasonal flu took an unexpected hiatus, largely thanks to social distancing and other measures such as mask-wearing, which were implemented to curb the spread of the covid-19 pandemic. Although covid-19 still managed to cause the highest peak of disease seen in the United States to date during those months, the less contagious flu effectively disappeared.
But states and the federal government have made it clear that mass vaccination is not restrictive measures, will be the main strategy to control the pandemic going forward. So Americans are likely to spend more time around others and in big gatherings this winter. Many experts remain cautious that we may see a resurgence of both influenza and covid-19 – a so-called twindemic. Cases of covid-19 in the United States have began to climb again recently after a fall, while deaths and hospitalizations remain stubbornly high. Although it is too early to say whether the flu will return to full force this year, the current outbreak at the University of Michigan is not an encouraging sign.
“This outbreak doesn’t necessarily have an immediate impact on the wider local community, but it does raise concerns about what the flu season can bring,” Marquez said.
Of course, we have vaccines available to train our immune systems against both viruses. The original shots of covid-19 continue to provide high protection against the worst outcomes of the disease, and it is make it clear now these booster doses restore the high efficacy of the vaccines against infection and transmission, at least temporarily. La seasonal flu vaccine is generally less effective against the rapidly developing flu, but it still prevents a considerable number of sick days, hospitalizations, and deaths each year. In particular, 77% of the cases during this latest outbreak in Michigan were unvaccinated.
Officials recommend that everyone at the university be vaccinated as soon as possible, and the university holds a vaccination on Tuesday.