Each winter, many people wonder whether it’s worth getting a flu shot while health officials repeatedly warn against not getting one.
Now a new study sheds light on the benefit of doing so. Even when the flu shot is just 20% effective it can still reduce US doctor visits due to illness by an estimated 20 million in a single year, the new report published in the scientific journal PNAS (Proceedings of the National Academy of Sciences of the United States) finds.
In addition, vaccination also can prevent thousands of hospitalizations and deaths, the study authors estimated based on the average vaccination coverage rate in the United States.
“Getting vaccinated against influenza is beneficial to the individual and to the community even when the vaccine is of relatively low efficacy,” said Burton H. Singer, co-author of the study and an adjunct professor for the Emerging Pathogens Institute at University of Florida in Gainesville.
Caused by viruses, flu is a contagious respiratory illness with mild to severe symptoms that can sometimes lead to death. The flu virus evolves rapidly and new viruses circulate in different parts of the world, so each year scientists must reformulate the vaccine. Add to that an imperfect manufacturing process and even a ‘good match’ reformulation may not be as effective as scientists would like.
In fact, the Centers for Disease Control and Prevention estimated just 36% effectiveness for the 2017-18 seasonal vaccine as of February 3. (The season ends in May.)
For the new study, Singer and his colleagues created a mathematical model of flu transmission and vaccination to evaluate how much illness is prevented by even a very low effectiveness flu vaccine. The research team found that at the average rate of US coverage even a poor vaccine would prevent a significant amount of illnesses, hospitalizations and deaths.
For example, at just 43% coverage (the average rate of Americans who received a flu shot for the years 2012 through 2017), a vaccine with just 20% effectiveness could avert more than 20 million infections or illnesses as compared to not getting the vaccine. In addition, 129,000 hospitalizations and 61,000 deaths could be prevented.
Based on the model, if more people got a flu shot, say half of the US population, the same 20% effective flu shot would prevent an additional 3.63 million infections, 21,987 hospitalizations and 8,479 deaths.
READ MORE: https://www.clickondetroit.com/health/even-bad-match-flu-vaccine-saves-lives