SEATTLE — Despite being back in the season of sniffles and sick days, Washington state will be extra equipped to battle the spread of respiratory viruses this year.
Influenza, RSV and SARS-CoV-2 are still the top three viruses to watch out for in the fall and winter, but several public health tools that have become available in the past year should help boost protection measures, a panel of UW Medicine doctors said in a Tuesday news conference.
“What we’re looking at now is probably the first true post-pandemic season of respiratory viruses,” Dr. John Lynch, an infectious disease doctor at Harborview Medical Center, said during the discussion. “[We have a] greater understanding of what the trajectories are around viruses, in terms of their epidemiological trends.”
Since the pandemic began, some respiratory virus trends have changed dramatically. One lineage of influenza B, for example, disappeared and still hasn’t returned, while a “tripledemic” of flu, RSV and COVID slammed the region simultaneously two winters ago. Some factors, like COVID variants, might still be unpredictable, but ever-evolving public data dashboards and recent vaccine updates will hopefully prepare Washingtonians to defend against the worst of the sick season, which can be particularly dangerous for children and older adults, Lynch said.
Doctors are particularly excited about one specific treatment that protects infants against RSV — and could mean less severe illness and hospitalizations among kids.
The U.S. Food and Drug Administration last year approved nirsevimab, the RSV monoclonal antibody treatment, for babies and toddlers at increased risk of severe RSV, along with three RSV vaccines for adults over 60 and a vaccine for pregnant people. But there weren’t enough nirsevimab doses, and health officials reported shortages throughout the country, including in Washington.
“We did not have enough supply to meet demand; and by the time we had supply, demand for the product waned later in the season,” the state Department of Health’s Office of Immunizations said this week.
To immunize 70% of babies recommended for the shot, state officials estimated Washington would need about 60,000 doses of nirsevimab, though the actual amount needed depends on patient demand.
Last season, providers ordered about 28,500 doses and administered about 15,400. This fall, providers have already ordered more than 19,000 doses, though the office said more will be available as the season continues.
The state also had about 13,000 unused doses by the end of last season, which it can use this year, the office said.
A greater supply of nirsevimab could make a big difference for pediatric hospitals during the winter, said Dr. Helen Chu, an infectious disease doctor and UW professor of medicine and epidemiology. Chu also sits on the U.S. Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices.
“I think it’ll be a really different season than what we’ve seen in the past,” Chu said. “Where suddenly hospitals are not filled to capacity and won’t have to go on divert during RSV season because babies will receive this monoclonal antibody at birth and won’t end up having to be hospitalized with RSV infections.”
“It’s a remarkable achievement,” she said.
In March, the CDC reported the shot was 90% effective in reducing RSV hospitalizations among infants.
At Seattle Children’s, RSV is one of the most common reasons infants younger than 6 months old end up hospitalized or in the emergency department during the winter, said Dr. Surabhi Vora, the hospital’s clinical director of pediatric infectious diseases.
Vora is also encouraged by the nirsevimab news. Scrambling to get shots last year was “a bit chaotic,” she said.
“This is the first year where we have all these tools in place at full capacity, so it’s going to be interesting to see what happens,” she added. “I’m really optimistic this is going to be a better year.”
Updated COVID shots are available in doctor’s offices and pharmacies, as well as renewed flu shots, which are a little different this year (they no longer contain protection against the influenza B lineage that’s stopped circulating).
COVID levels are coming down since the region’s late summer surge, and influenza and RSV numbers remain low, Chu said.
“There’s a few trace positives” of flu and RSV circulating in the Seattle area now, said Dr. Alex Greninger, a professor of laboratory medicine and pathology who helps run UW Medicine’s virology lab and virus-sequencing efforts. But the height of respiratory virus season generally falls around December and January, he said, so things are still ramping up.
“It’s just the beginning,” Greninger said Tuesday. “That’s why we’re having this conversation right now. It’s a great time to get vaccinated.”
