H3N2 flu virus spreads nationally, coupled with a ‘mismatched’ vaccine

Simone Wolberg

Mutated forms of the H3N2 flu virus have spread widely throughout California and 43 other states, Centers for Disease Control and Prevention (CDC) officials wrote in a recent press release.

Combating this H3N2 viral strain is especially difficult because vaccine effectiveness has dropped from 60 percent in 2014 to around 30 percent this year due to unexpected mutations, according to Danielle Hiser, Marin County’s Immunization Coordinator and Public Health Nurse.

This year alone, the H3N2 viral strains have accounted for 26 pediatric deaths and doubled hospitalization rates for senior citizens, according to Tom Frieden, Director of the CDC, in a Jan. 2015 telephone conference.

Vaccine infographic

In Marin County, the percentage of visits to Marin General, Kaiser, and Novato Community Hospital for influenza-like illness was at 16.9 percent during the week of Jan. 3 and decreased slightly to 14.8 percent during the week of Jan. 10, according to the Marin Health and Human Services Department.

The CDC anticipated an H1N1 “Swine Flu” outbreak similar to last year, but instead an H3N2 outbreak occurred. H1N1 and H3N2 are different types of the flu which manifest the same symptoms.

“What we’ve seen so far is that the large majority [of viruses] in Marin County and the greater California are variants of the H3N2 virus,” Hiser said.

The current vaccine contains four different viral strains, two of which are H1N1 and H3N2 while the other two are lesser known “B strains,” according to Hiser.

Since vaccines typically need a year to develop, producers are always somewhat behind in developing an effective product. As newer technologies are improved upon, however, vaccine quality and quantity will improve rapidly, Hiser said.

“What’s cool about the new and improved recombinant vaccines is that it only takes nine to 12 weeks to make. As we improve this technology, perhaps by 2019, we’ll be able to make more effective vaccines on a shorter notice,” Hiser said.

Senior Melissa Papuc, President of the Redwood Pre-Medical Club, said her club is currently researching the flu and had a presentation about the flu during a club meeting.

“We [talked] about the science behind it, why this year’s vaccines did not work so well, and the safety precautions one should take,” Papuc said.

Although this year’s vaccine is not as effective as those in some years past, Hiser said it is still important to get a flu shot.

“Even when a vaccine is not perfectly matched, one should definitely still get vaccinated because it will still protect your immune system from other common strains,” Hiser said.

Hiser warned of the increased severity of the H3N2 viruses compared to previous years.

“Back in 2009 with the H1N1, one thing that really stood out was that it was hitting a lot of middle aged healthy people and making them ill,” Hiser said.  “Although H3N2 does not target those middle-aged groups, it is still very severe since infants, pregnant women, and the elderly can easily contract it.”