Influenza has been with us for a long time. More people died from influenza during the 1918–1919 influenza pandemic than died during World War I. Like all viruses, influenza is very good at finding ways to mutate and bypass our immune system defenses. We have been able to stay a step ahead by developing vaccines that stimulate our immune system to fight off these potentially deadly viruses.
Periodically however, influenza outsmarts us by mutating or shifting into a virus that our immune systems fail to recognize. When this happens, influenza pandemics can occur, as happened in 1918 with disastrous results. Although public health officials are rightly concerned about pandemics, seasonal influenza kills many thousands of people every year and many of these deaths can be prevented by getting a flu vaccination.
In past years CDC has emphasized the importance of increasing vaccination rates among high-risk groups, working toward a goal of universal vaccination. To that end, in 2010, in an attempt to simplify vaccination recommendations and increase vaccination rates, CDC issued guidelines stating all individuals aged 6 months or older should be vaccinated annually. This universal vaccination guideline reflects lessons learned from the 2009 H1N1 pandemic.
Despite these strong recommendations, more than half of the general public and about 25% of healthcare workers fail to get vaccinated against flu each year. The situation is particularly dire in long-term care settings, where some of our most vulnerable citizens are exposed to influenza by unvaccinated workers, visitors, and residents. Getting vaccinated each year protects high-risk populations from catching the flu from the people who are supposed to be helping and protecting them.
Vaccination is available in a live-attenuated (LAIV) and an inactivated (IIV) form. Knowing which one works best for you and your patients is important. The makeup of this year’s influenza vaccine is based on information about which influenza viruses are circulating, how they are spreading, and how well the previous season’s vaccine viruses protected against any that are being newly identified.
VE (vaccine effectiveness) data collected from children and adults enrolled in the U.S. Influenza Vaccine Effectiveness Network from Nov. 23, 2018 through Feb. 2, 2019 indicate that the flu vaccine reduced the risk of acute respiratory virus infection (ARI) by 46% (CDC, 2019h).
Children ages 6 months to 17 years who were vaccinated against flu last season reduced their risk of contracting influenza A(H1N1) illness by more than 62% and their risk for illness from all influenza types by 61%. For all ages, the CDC said VE against influenza caused by A(H1N1) virus infection was 46%, and VE against illness due to influenza A(H3N2) was 44% (CDC, 2019h).
For the 2019–2020 U.S. influenza season, providers may choose to administer any licensed, age-appropriate influenza vaccine (IIV, recombinant influenza vaccine, or LAIV4). LAIV4 is an option for those for whom it is otherwise appropriate. No preference is expressed for any influenza vaccine product (Grohskopf et al., 2019).
Vaccination should be offered as long as influenza viruses are circulating. To avoid missed opportunities for vaccination, providers should offer vaccination during routine healthcare visits and hospitalizations when vaccine is available.
Getting an annual influenza vaccine provides the best protection against influenza for virtually everyone.