February 4, 20256 min readHow Bad Are COVID, Flu and RSV This Winter?COVID levels may have peaked but flu is still high; RSV is on the way outBy Tanya Lewis edited by Dean Visser Amanda Montaez; Source: Centers for Disease Control and Prevention (data)If it seems like almost everyone you know is getting sick with influenza or some other virus right now, its not your imagination. The Northern Hemispheres respiratory illness season, which typically runs from October to May, is in full swing. Flu hospitalizations appear to have declined from an initial peak in January, but they remain high, and cases may be rebounding. Levels of the virus that causes COVID detected in wastewater are also high but declining. And respiratory syncytial virus (RSV) is still putting people in the hospital, albeit at lower levels than flu or COVID. Yet despite all the sniffles, its shaping up to be a fairly typical year for respiratory viruses.FluSo far, this years flu season looks pretty similar to that of previous yearswith the exception of 20202021, when flu all but disappeared because of COVID-related masking and social distancing measures. This seasons weekly hospitalization rate reached a peak around January 4 and then appeared to decline, though the Centers for Disease Control and Prevention indicated there may be possible delays in reporting. The latest positive test rate data (some of which were released several days late under the new presidential administration) show a slight rebound in infections, so we may not be out of the woods. There have been some reports that this years flu vaccine might be less effective than in previous years, which could explain the apparent high levels of sickness that are currently around. But this season doesnt seem to be particularly more severe than others.On supporting science journalismIf you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.Amanda Montaez; Source: Centers for Disease Control and Prevention (data)This years flu season started a bit late, saysJennifer Nuzzo, a professor of epidemiology and director of the Pandemic Center at the Brown University School of Public Health. But were still in the thick of it, she says. I dont know how its going to play out, Nuzzo adds.To prevent becoming seriously ill with flu, health officials still recommend getting the flu vaccine if you havent already, especially if you are age 65 or older or have underlying health conditions. Masking, avoiding crowds and being in well-ventilated spaces are always helpful at reducing the chance of getting infected. And if you should test positive for flu, antiviral drugs such as Tamiflu are available by prescription.The fact that this years season started slightly later than last years is a relief, Nuzzo says, in light of the ongoing H5N1 avian influenza outbreaks in cows and poultry that have caused 67 human infections and one death in the U.S. Nuzzo is worried about people getting infected with both H5N1 and seasonal flua situation that could increase the risk of bird flu adapting to humans and becoming a pandemic. Im a bit relieved because I was fretting about the co-occurrence of H5N1 and seasonal influenza, she says. Im worried about humans getting infected with both viruses.COVIDThere has been a much smaller spike in COVID hospitalizations this winter, compared with previous ones. Thats likely thanks to widespread immunity from vaccination or infection, or both. The U.S. also had a substantial late summer COVID spike in 2024, so some of the immunity from infections during that time may have prevented a large winter surge.Amanda Montaez; Source: Centers for Disease Control and Prevention (data)The virus that causes COVID, SARS-CoV-2, hasnt mutated much recently, says Katelyn Jetelina, an epidemiologist who writes the popular newsletter Your Local Epidemiologist and consults for the CDC. In addition, more people older than age 65 were vaccinated this season than last season, she says. And wastewater levels of the virus appear to have peaked.COVID hasnt really settled into a seasonal pattern like flu and RSV. It seems to peak at least twice a year, including during the summer, which suggests that transmission may be driven at least as much by human behavior as by weather or other environmental factors. Some of it is our behavior. Some is just opportunitysort of like Boggle, Nuzzo says. Each season you shake up the cubes and see what happens.The COVID vaccine is still the best way to protect against severe illness, and most experts recommend that at least older adults and those who are immunocompromised stay up to date on the shot. For those who get COVID and are at high risk of severe disease, experts recommend the antiviral medication Paxlovidas long as you can start taking it within the first five days after symptoms appear. Studies suggest it offers less benefit for people who arent at high risk, however, and it can interact with many other common medications, so seek medical advice if youre unsure.COVID still kills more people overall each year than the flu, although flu hospitalizations this winter are double those for COVID, suggesting that flu has had a more concentrated winter peak. Its not clear whether SARS-CoV-2 will eventually evolve to be less severe than flu virus. We cant say definitively no, Nuzzo says. Generally speaking, as a population, we are less susceptible to severe COVID-19 disease. But never say never. Ive been humbled by this virus several times.RSVLike flu, RSV is having a fairly typical year. Hospitalizations appear to have already hit a high mark for the season and are on the way down. This year is not too bad. Many people think were at the peakof RSV infections, says Peter Chin-Hong, a professor and associate dean for regional campuses at the University of California, San Francisco, School of Medicine.Amanda Montaez; Source: Centers for Disease Control and Prevention (data)During the COVID pandemic, RSV showed a slightly odd pattern: like flu, it basically disappeared in the 20202021 season, likely because of masking and social distancing. But in 20222023 it came roaring back and had a large, early peak during the fall. Last year saw a significant surge as well, but it was closer to the timing of a typical season.Chin-Hong thinks this years somewhat milder RSV season may be the result of the virus settling back into a normal pattern. Also, in 2023 RSV vaccines for older adults and pregnant people were finally approved, and that may have protected more individuals. Theres still a lot of room to [vaccinate] the older population, Chin-Hong says. In addition, theres now a prophylactic antibody drug available to protect young children and newborns from RSV, and uptake of that has been pretty good, he adds.Other VirusesFlu, COVID and RSV arent the only nasty bugs that are circulating, of course. This season has seen one of the worst outbreaks of norovirusa nasty gastrointestinal pathogen that causes symptoms similar to food poisoningin the past decade. Between August 1, 2024, and January 15, 2025, there were more than 1,000 norovirus outbreaks reported in the U.S. By contrast, last season there were only about 550 during the same time period.The likely reason for this surge is that the virus has mutated to a form that fewer people have immunity to. Outbreaks usually happen when the virus has evolved and population immunity is low, Jetelina says.This season nearly 70 percent of norovirus outbreaks have been caused by an atypical variant of norovirus, she says.Then theres human metapneumovirus (HMPV). In early January a flurry of news reports said HMPV cases were surging in some countries in Asiabut this isnt a new virus, and experts say it doesnt pose a major threat. Positive HMPV tests in the U.S. showed a slight uptick in January, but that appears to have subsided.And of course, at any given time theres a veritable stew of common cold viruses going around. These include rhinoviruses, adenoviruses and seasonal coronaviruses. Such viruses dont usually send people to the hospital, but they can make you feel crummy. Most cases can be treated at home with hydration and rest.As always, its a good idea to stay home if youre not feeling well (and can afford to). Limiting contact with others or wearing a mask can help limit the spread. And washing your hands with soap and water is important, especially for norovirus, because hand sanitizer doesnt kill the virus.