According to the Centers for Disease Control and Prevention (CDC), the severity of the influenza season in the United States has reached epidemic proportions. The flu has killed 15 children and has been responsible for the hospitalizations of 2, 643 patients between October 1, 2014 and December 20, 2014. Influenza and pneumonia were also responsible for 6.8 percent of all deaths reported in 122 cities in the United States.
This year’s flu season is particularly severe due to the prevalence of the influenza A H3N2 strain, which is associated with a higher rate of hospitalizations and deaths. Half of the H3N2 viruses analyzed are drift variants: viruses with antigenic or genetic changes that make them different from the season’s vaccine virus. This means that the flu vaccine does not inoculate against the H3N2 strain, but the CDC is still urging the public to get vaccinated, particularly those persons at high risk. This includes those individuals who work in the healthcare industry. Other high risk individuals include the following: children younger than 5 years (especially those younger than 2 years); adults 65 years and older; pregnant women; and people with certain chronic health conditions such as asthma, diabetes, heart or lung disease, and kidney disease.
“While the vaccine’s ability to protect against drifted H3N2 viruses this season may be reduced, we are still strongly recommending vaccination,” stated Joseph Bresee, M.D., Chief of the Influenza Epidemiology and Prevention Branch at the CDC. “Vaccination has been found to provide some protection against drifted viruses in past seasons. Also, vaccination will offer protection against other flu viruses that may become more common later in the season.”
According to CDC Director Tom Frieden, M.D., M.P.H., a three-pronged approach is needed to fight the flu: vaccination, prompt treatment for those at high risk for complications, and preventive health measures, such as staying home when ill to reduce the spread of flu. Antiviral drugs, such as Tamiflu (oseltamivir) and Relenza (zanamivir), should be administered promptly to those individuals at high risk for complications who contract the flu virus. Studies indicate that these medications work best for treatment when they are started in the first 48 hours after symptoms appear. Flu symptoms can include fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills, and fatigue.
Flu viruses constantly mutate and change. This makes it challenging for the committee of experts who select the viruses to be included in the vaccine, especially since the selection process takes place many months in advance of vaccine development. Viruses can drift during the planning and development stages, just as the H3N2 strain did.