Influenza has long plagued the United States causing flu seasons that last for weeks which result in both fatalities and overcrowded hospitals throughout the winter months. According to the Center for Disease Control, this year’s influenza season has been one of the deadliest within the last decade. So far it has been estimated that this season there have been at least 19 million flu illnesses, 180,000 hospitalizations, and 10,000 deaths from flu. The CDC has reported that the B strain of the virus has become prevalent earlier in the flu season, but there has been a recent increase in the A strain of the virus. I feel that this is concerning because the A strain is usually more severe and its recent increase may be an indication of a more severe flu season. While the flu virus can cause fatalities, those who are immunocompromised such as children, pregnant women, and older people (over 65) are at the highest risk.
Often the symptoms of the flu aren’t the biggest issue, it’s the complications. Those infected with the flu may get pneumonia, bronchitis, and sinus and ear infections. Many of the fatalities experienced from the flu are due to pneumonia related complications. Personally, I think a large issue arises when people decide to not get the flu vaccination because they feel it doesn’t work, or they have gotten the flu vaccine in the past and have still acquired the virus. I feel that this is a large problem because children under the age of 2 cannot receive the flu shot and are immunocompromised because they have not established adult immunity yet. Thus, these children are at a very high risk of getting a severe case of the flu at the expense of others’ decisions.
One of the causes for influenza’s recurrence and unpredictability in its severity is a result of antigenic drift that continuously changes the genetic composition of the virus resulting in a novel virus each year. This change in the virus often produces a virus that most of the population doesn’t have immunity to causing the virus to result in yearly outbreaks. This year’s vaccine contains updates from last year with components of A/Brisbane/02/2018 (H1N1)pdm09-like virus, A/Kansas/14/2017 (H3N2)-like virus, and the same B/Victoria and B/Yamagata virus from last year. Additionally, the only regular dose vaccines available this season are quadrivalent meaning they contain four components. It has been reported that this year’s vaccine is a good match for the circulating strains of viruses which should help to control the virus. However, due to the abnormal early circulation of strain B, the congruence of the vaccine to the circulating viruses doesn’t mean the 2019-2020 flu season is any milder. It will be interesting to see where the course of this year’s flu outbreak within the next couple of months, especially since there have been a peak number of flu cases in February in past flu seasons.
Allison Roney's Microbiology Blog 