Doctors are anticipating a typical respiratory virus season this fall and winter, with flu, COVID-19, and RSV expected to circulate. Although the southern hemisphere's flu season was reportedly less severe than in recent years, health experts stress the importance of vaccination and preventative measures to mitigate illness.
Flu season typically begins in September or October and can last through March or April, often peaking in December or January. Dr. S. Wesley Long, medical director of diagnostic microbiology at Houston Methodist Hospital, noted that flu A strains usually appear earlier in the season, followed by flu B strains. While both cause similar symptoms, flu A is more common.
Early indicators from the southern hemisphere's winter flu season, which runs from May to September, suggest a less severe season than the past two years. Dr. Morgan Katz, an associate professor of medicine at Johns Hopkins University School of Medicine, described the southern hemisphere's season as "lighter and later," offering some encouragement for the upcoming season.
The shift to indoor activities as temperatures drop is a key factor in the increased spread of respiratory viruses. "The big thing is that we're inside more. We're closing our windows, and we're just not getting the ventilation and outdoor activity that we get during the summer months," Katz explained. This increase in indoor congregation is expected to lead to a rise in COVID-19 cases, though it does not disappear entirely in warmer months.
RSV, or respiratory syncytial virus, is another seasonal virus that primarily affects infants and older adults, though it can cause cold-like symptoms in healthy individuals. RSV activity is currently low nationwide but is expected to rise through the fall and winter, potentially peaking in January. New RSV vaccines for infants, pregnant individuals, and older adults have shown effectiveness in reducing hospitalizations.
Colds, caused by a range of viruses like rhinovirus and enterovirus, are also most common during the fall and winter. Unlike flu and COVID-19, there are no specific antiviral treatments for common colds. However, doctors recommend testing for flu and COVID-19 if respiratory symptoms arise, as antiviral treatments are available for those illnesses.
To protect against these circulating viruses, vaccination remains the primary recommendation. "I just can't emphasize enough that flu, COVID and RSV vaccines, if you're eligible to get them... I think it would be very important to try and get them and talk with your doctor about your individual risk," said Dr. David Nguyen, an assistant professor of infectious diseases at Rush University Medical Center.
Beyond vaccination, health experts advise maintaining practices learned during the COVID-19 pandemic, such as avoiding large crowds and poorly ventilated indoor spaces, minimizing contact with sick individuals, and considering mask-wearing. "All the non-pharmacologic measures are good for any respiratory virus during the cold and flu season," Long stated. "All those sorts of things can be helpful in avoiding getting sick."