The CDC reports a mid-season efficacy rate of 50% for this year’s flu shot, being 45% effective for adults and 55% effective for children, up from a 47% estimated efficacy last year.
In a good year flu shot efficacy may be 65%. It’s difficult to reach higher numbers as viral flu strains mutate easily and immune systems of the general public are so varied. Per the CDC the flu shot during the 2010-2011 flu season was one of the most effective.
This year two waves of flu strains hit the country, Influenza B and H3N2. But despite the double whammy the flu shot offered fair protection.
They report the following:
The interim VE estimates published today also estimated the benefits provided by vaccination in different age groups. In addition to the VE estimate of 55% reported among children 6 months through 17 years of age, VE was estimated to be 25% among adults 18-49 years old, and 43% among adults 50 years of age and older. The lower VE point estimates observed among adults 18-49 years appear to be associated with a trend suggesting lower VE in age this group against A(H1N1)pdm09 viruses (VE = 5%). CDC will continue to monitor VE in this age group against A(H1N1)pdm09 viruses as more study participants are enrolled throughout the season. This will help CDC determine if VE against A(H1N1)pdm09 viruses in this age group is actually lower than in previous seasons, and if so, to investigate possible causes.
This year an estimated 26 million people were affected by the flu with over 250,000 hospitalizations and 14,000 deaths.
To date, 92 children have died this year from flu related illness, being a more severe season for children.
Flu season peak is still occurring and high flu activity is still being reported in multiple states.
It is not too late to get the flu shot and medical providers are still recommending vaccination.
Daliah Wachs, MD, FAAFP is a nationally syndicated radio personality on GCN Network, KDWN, iHeart Radio and is a Board Certified Family Physician