A troubling flu strain
Tina Tan, state epidemiologist for the New Jersey Department of Health, said it's troubling that the predominant strain of flu so far is A(H3N2). That type, she said, is "sometimes associated with a more severe flu season." That could mean both sicker patients and more cases.
Amber Liggett, a public information officer for the Pennsylvania Department of Health, said her agency is also worried about the early arrival of H3N2. "H3N2 is known to cause more complications and deaths, and seasonal vaccines are known to have lower efficacy against it," she said.
Last year's very low flu numbers created a challenge for vaccine makers: predicting which strains of flu would make the rounds this year, Cennimo said. Normally that's based on what happens in the Southern Hemisphere, but very little did. This year's shot protects against a version of H3N2 found in Cambodia in 2020. It's too soon to know how well it will work.
The CDC said Friday that overall flu numbers were low but increasing during the week ending Nov. 13. Ninety percent of cases were among children and young adults aged 5 to 24. While this group is not at high risk for serious illness, it can play a key role in spreading the virus to more vulnerable younger children and older adults.
New Mexico stood out for having high flu activity. The CDC put Pennsylvania and New Jersey in the "low" category. Activity in Delaware was "minimal." So far, there have been no pediatric deaths in the country, but Pennsylvania reported that one adult over 65 has died of flu this fall.
In its report for the week ending Nov. 13, Pennsylvania's Health Department said cases had increased significantly in the last week. They were slightly higher than they had been for that time period during any of the last eight years. The department said there have been more than a thousand laboratory-confirmed cases so far, and they have been found in 52 of 67 counties.
Liggett said testing has increased because of concerns about COVID-19, and that makes yearly comparisons difficult.
New Jersey itself described flu activity as "moderate" overall for the week ending Nov. 13. It was low in southeast New Jersey and moderate in the southwest. So far, the activity level is similar to what was seen in 2018-19 and 2019-20.
Philadelphia, meanwhile, has had "almost nothing" — just five cases, said James Garrow, a spokesperson for the Philadelphia Department of Public Health. Flu typically hits hardest after the new year, he said.