Flu and the respiratory syncytial virus (RSV) season has just started in the Northern Hemisphere, and the consensus among experts is that the 2022-2023 season is shaping up to be more severe than in recent years (relatively mild). It could even be worse than the seasons before COVID-19.
Health data company IQVIA has been analyzing insurance claims data filed by doctors’ offices, hospitals and urgent care centers in the country for three decades, focusing on case trends over the past year. The team found that flu diagnoses are already being reported at record levels. Even before the flu season began, in the spring of 2022, influenza cases began to trend well above the average of the last three years, reaching almost 950,000 weekly cases in mid-October (compared to about 400,000 in the same period in 2019, just before the pandemic). it started).
These higher rates are not completely unexpected. Influenza cases dropped significantly during the first two years of the pandemic, when people had less contact with each other and generally followed mitigation measures to control COVID-19, such as wearing masks and social distancing . Those behaviors helped suppress the spread of the flu. But, says Murray Aitken, executive director of the IQVIA Institute, current flu numbers are “trending higher each year since 2012 by a significant amount.”
Experts are also concerned about another worrying trend in the flu. Flu season in the southern hemisphere, which often gives the US a preview of what to expect, hit early and hard this year. Australia, for example, faced its worst flu season in five years, with nearly 30,000 laboratory-confirmed influenza cases at its weekly peak in June; flu season tends to peak later, between July and September.
Other respiratory viruses, SARS-CoV-2 and RSV, are also on the rise. COVID-19 continues to be responsible for approximately 260,000 infections every week in the US on average, and laboratories that are part of the US Centers for Disease Control and Prevention’s National Respiratory and Enteric Virus Surveillance System have reported 500% increase in percentage of positive tests for RSV from early September. RSV affects children and the elderly more severely. “This virus is hitting extremely hard this year,” says Dr. Juanita Mora, a spokeswoman for the American Lung Association and an allergist and immunologist at the Chicago Allergy Center. One of the reasons cases are rising so fast (especially among younger children), and so early in the season, could be because of COVID-19 restrictions that have closed schools and kept children home. they protected many of them from infection in the past two years. . “Usually 100% of children will have had RSV by two years, but that is not the case now,” says Mora. “For the last three years, we haven’t had an RSV season, so we have a cohort of children who lack the immunity that they would normally have.”
While there is a vaccine to protect children from RSV, it is only approved for children at higher risk of developing serious illness, such as premature babies and those born with lung or heart disease. The vaccine requires monthly injections during the infection season and most children are not eligible to be vaccinated. For them, Mora says, the best protections are the same behaviors that protect children from the flu and COVID-19: keeping children up to date on flu and COVID-19 vaccines, washing hands frequently and avoid close contact with children who are coughing or sneezing.
With flu and RSV cases rising so rapidly, hospitals in some parts of the country are already feeling pressured. But the situation could get worse as new variants of COVID-19some of which are evading vaccination protections, continue to proliferate this winter.
What is contributing to the rapid and historic rise in respiratory disease? It’s likely a combination of factors, including the mild seasons during the early part of the pandemic, as well as slow flu vaccination rates. Although it is still relatively early in the flu season, flu vaccine uptake is nearly 9% below normal now during the years leading up to the pandemic.
Experts say that while these signs are worrying, the US is not necessarily doomed to suffer as severe a viral season as countries like Australia. If more people get vaccinated against the flu and COVID-19, that could cushion the effects of viruses that circulate more than usual.
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