This year’s flu season may be shaping up to be particularly harsh, and the vaccine used this year may not be as effective as first thought, according to medical experts.
Based on reporting about illness and deaths caused by flu in Australia which was higher than usual, the experts predict North America will also experience a more severe flu season.
The flu vaccine used this year in the Southern Hemisphere has the same composition as the vaccine available in the United States. Unfortunately, this vaccine was only 10 percent effective at preventing H3N2, the dominant strain of the virus that circulated during Australia’s flu season, the researchers wrote in the New England Journal of Medicine.
So what should you do? “People should continue to get the flu shot,” said Dr. Charles Bregier, Novant Health medical director of corporate health.
The U.S. flu season may not be identical to Australia. “The flu vaccine contains four different strains – two influenza A strains and two influenza B strains, so if the vaccine is not particularly effective at preventing the H3N2 strain, that doesn’t mean it is ineffective with the other three strains of flu found in the vaccine.”
Also, Bregier explained there is no predicting whether the H3N2 will be the dominant strain of flu here in the U.S. “Only time will tell,” he said.
“The flu vaccine is normally 50 to 60 percent effective. When there is a bad match for the viruses in circulation, the effectiveness is lessened but it is still very protective,” Bregier said.
Can we hope for more effective vaccines in the future? Bregier believes so. He thinks as science improves, we may have flu vaccines that are cell-based rather than egg-based as we do now. He said it’s difficult to create a universal vaccine for every possible strain of flu because the viruses tend to change rapidly.
Modifying the vaccine to whatever strain is dominant can be difficult as well. “It takes about six months to produce the flu vaccine,” Bregier said. At that point, the flu season probably would have long since peaked.
“Flu season is building,” he said. “In a bad flu season, it’s best to get as much protection as possible.”