A new version of the H3N2 flu strain that surfaced over the summer is spreading quickly overseas, raising concern as the U.S. moves further into flu season. Canada and the U.K. both report stronger-than-normal activity for November, and some hospitals there are handling more patients than they usually see at this stage.
The government shutdown halted detailed national reporting, so the Centers for Disease Control and Prevention hasn’t posted a full update since late September. Without that information, health officials are leaning more heavily on state surveillance and what they’re seeing abroad. In New Jersey, flu levels remain low, but officials expect activity to pick up once holiday travel and indoor gatherings increase.
A Strain That Shifted After Vaccine Decisions
Flu vaccines are finalized months before the season begins. Health agencies choose strains in February based on activity in the Southern Hemisphere. This year’s shot includes two influenza A strains and one influenza B strain. The H3N2 flu strain drawing attention didn’t become widespread until months after that process ended.
Researchers in the U.K. say the strain collected several genetic changes over the summer, creating differences from the H3N2 included in the current vaccine. Early data overseas still shows the shot helping reduce severe illness, even in a mismatched year.
Overseas Activity Showing a Fast Start
Flu levels in the U.K. sit several times higher than they did at this point last year. Emergency departments there are already feeling the strain. Canada is reporting a similar trend, especially among older adults who tend to see more complications during H3N2 seasons.
Japan is also seeing an unusually early start. Tokyo logged flu levels far above last fall’s numbers, and more than 2,000 day cares and schools there closed sections or adjusted schedules to manage outbreaks. Those kinds of changes rarely happen this early.
These developments suggest the Northern Hemisphere may face a quicker climb than in recent seasons.
Unclear Picture in the U.S.
Doctors in several states report rising flu A cases, but without updated national surveillance, it’s hard to tell how much of that involves the new variant. Federal staffing cuts may slow analysis once reporting resumes, which shifts more of the monitoring to state laboratories and academic centers.
What New Jersey Should Know
New Jersey’s Department of Health continues to report low flu activity statewide. Flu shots remain easy to find at urgent-care centers, pharmacies and primary care offices. Health departments expect more residents to seek testing and vaccinations once holiday travel and indoor events become more frequent. Early flu activity in other countries can offer useful signals about how the season might develop locally.
Long-term data shows the vaccine consistently lowers the risk of hospitalization and severe complications, even when circulating strains differ from the vaccine’s formulation. State health officials encourage residents to get vaccinated ahead of the holidays, stay home when sick and pay attention to symptoms as the season develops.
For New Jersey, preparation stays simple: get the shot early and take basic precautions as flu activity shifts.
The New Jersey Digest is a new jersey magazine that has chronicled daily life in the Garden State for over 10 years.