Flu vaccines are developed following predictions scientists make regarding which strain of the virus the vaccines will be made to combat. There's never a 100 percent success rate but it looks like it's going to be worse this year, no thanks to predictions being off.
Drug manufacturers start producing vaccines between four to six months before the start of flu season. This means that scientists have to predict which virus strain vaccines should focus on at the first half of the year. Unfortunately, data from which predictions are based on can be different from the actual conditions in which flu vaccines will be used in.
"One thing to understand about flu always is that it is unpredictable. Every season is different," said Dr. Thomas Frieden, Centers for Disease Control and Prevention director.
According to the CDC, 82 percent of samples tested identified the H3N2 virus. Out of that number, only 48 percent of the samples are in close relation to the A/Texas/50/2012 strain that was used for flu vaccines made available in North America. What most of the H3N2 samples do closely resemble is the A/Switzerland/9715293 strain that was used for flu shots distribute in the Southern Hemisphere.
With flu vaccines not matching the more common strain for this season, less protection is offered compared to previous years. On a good year, efficacy can reach 70 percent. The 2013 flu vaccine registered an efficacy rate of 50 to 55 percent.
While the current flu vaccine is not performing great, it remains a good vaccine. Those who haven't received flu shots are urged to be vaccinated because some protection is still better than no protection at all.
Each year, between 20 and 30 percent of children and 5 and 10 percent of adults get infected by the flu virus. Commonly, this means around a week or two of fevers, runny noses, coughs, muscle and joint pains, and headaches. However, between 3 and 5 million cases lead to severe illness, between 250,000 and 500,000 of which lead to deaths.
If there's no avoiding the flu, doctors at least can prescribe antiviral medication like Relenza and Tamiflu to shorten the infection and reduce sick days. Taking antiviral medication also reduces risks of complications, which cuts back on the likelihood of hospitalization and ultimately the risk of death due to influenza, added Dr. Frieden.
Individuals at higher risk of flu complications are children under two years old, adults older than 65 and people with heart disease, asthma, weakened immune systems or other chronic conditions.
