The Blubber

Flu, COVID-19, respiratory syncytial virus (RSV), and norovirus are circulating nationwide this winter, sparking mentions of a “quad-demic” (the first three are often referred to as a “triple-demic”). While the term for these four illnesses spreading simultaneously might sound alarming, this year’s respiratory virus season isn’t vastly different from those in the past.

“All of the viruses are present; they’re just impacting different areas in varying ways,” says Dr. Robert Hopkins Jr., medical director of the National Foundation for Infectious Diseases, in an interview with Fortune. “I don’t want to alarm people, but if you haven’t been vaccinated and are eligible—which includes everyone 6 months of age and older—get your COVID vaccine and your flu shot.”

For those eligible, RSV vaccines are also available: adults aged 75 and older, adults aged 60-74 with certain chronic conditions, and expectant parents later in pregnancy, Hopkins emphasizes. “We have the tools; we just need to use them.”

Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center, refers to this time of year as respiratory virus vaccination season. Staying current on immunizations, he says, is the best holiday gift you can give yourself and your loved ones.

“Benjamin Franklin put it well: ‘An ounce of prevention is worth a pound of cure,’” Schaffner tells Fortune. “We need to take action to prevent severe illness. Right now, we’re under-vaccinating.”

But what about protecting against norovirus, often called “winter vomiting disease,” for which no vaccine exists? Schaffner highlights the importance of hand hygiene.

“Use plenty of soap and water,” he advises, noting that alcohol-based hand sanitizers aren’t effective against norovirus. “It’s highly contagious, and you can pick it up from surfaces. If it gets on your fingers and you touch your nose or mouth, that’s how it spreads.”

Hopkins adds that the public health measures adopted during the early days of COVID remain effective in preventing illness.

“It’s crucial to cover your coughs, ideally with your sleeve or a handkerchief—not your hands,” he says. “Avoid people who are sick, stay home when you’re unwell, and consult your healthcare provider about testing and symptom management.”

Other recommendations include staying active, especially outdoors, maintaining a healthy diet and proper hydration, and being cautious in crowded spaces, especially for those at higher risk. “Crowds are natural breeding grounds for viruses to spread,” Hopkins warns.