HARTFORD -- The latest report from the New England Journal of Medicine has raised questions into how effective the flu vaccine will be this flu season.
The report said preliminary estimates show the flu vaccine may only be about 10 percent effective against one strain of influenza, H3N2.
Mick Bolduc an Epidemiologist with Connecticut’s Immunization program explained developing the flu vaccine each year starts around February.
“The world health organization will take a look at the strains that should go into the vaccine and then the manufacturers will start producing the vaccines,” Bolduc said.
He said from development to production is a roughly four to six month process, in which researchers use several factors to decide which strains go into the vaccine from year-to-year.
“The biggest one is looking at what happens in the southern hemisphere and in Australia,” Bolduc said.
The report from the New England Journal of Medicine states:
“The number of notifications reached 215,280 by mid-October, far exceeding the 59,022 cases reported during the 2009 H1N1 influenza pandemic, according to the Australian Government Department of Health. Influenza A (H3N2) viruses predominated, and the preliminary estimate of vaccine effectiveness against influenza A (H3N2) was only 10%. The implications for the Northern Hemisphere are not clear, but it is of note that the vaccine for this upcoming season has the same composition as that used in the Southern Hemisphere. As we prepare for a potentially severe influenza season, we must consider whether our current vaccines can be improved and whether longer-term, transformative vaccine approaches are needed to minimize influenza-related morbidity and mortality”
According to the Connecticut Department of Public Health, H3N2 is also the predominant strain right now in the U.S. and in Connecticut.
“The H3N2 is really the one that is not a great match or was not a great match in Australia so that’s where the worry is that if we see a lot of cases of H3N2 here in Connecticut that we will have a severe season,” Bolduc explained.
He also stressed that these are all preliminary estimates. He said studies have been conducted on the matter, but that the CDC typically studies vaccine effectiveness in January, when flu season is well underway.
“The key message really is that your best protection against flu is to still get an annual flu shot,” Bolduc said. He emphasized the flu vaccine protects against four different strains of influenza.
“There’s never going to be an influenza vaccine that’s 100 percent effective, there’s no vaccine out there that’s 100 percent effective but it is your best chance to avoid getting the flu. Even if it’s 10 percent or 20 percent or 50 percent effective that’s better than no protection at all,” Bolduc said.
Nationally, it’s expected a total of about 160 million doses of the flu vaccine will be distributed this flu season.
The state’s Department of Public Health reported a total of 142 cases of the flu statewide, with the highest number, 49, in Fairfield County. There have been no flu related deaths so far this flu season. Flu season typically peaks in Connecticut between January and March.