Every fall the CDC tells all Americans to get the influenza vaccine. The point of the exercise is to prevent the flu! That seems like a great public health initiative, especially now that the world is on edge about the coronavirus. If there were a vaccine against COVID-19 you can bet that millions of people would be lining up to get a shot. But here is a crucial question. How well did this year’s flu shot work? An early report has surfaced and it is not that impressive.
This Year’s Flu Shot?
How well is the influenza vaccine working this year to prevent the flu from making you sick? That is a question that won’t be definitively answered for several more weeks. Preliminary data from the CDC, however, offers a mixed bag of results.
The CDC likes to put a positive spin on its vaccine effectiveness (VE) data. That’s why you are seeing headlines that state the flu shot is 45 percent effective. That’s sounds pretty good. The CDC’s preliminary report implies that this is better than last year’s vaccine, making it well worth the effort.
Kids Do Well with This Year’s Flu Shot:
Children do appear to be getting decent protection against influenza. The public health experts state that the:
“vaccination provided substantial protection (VE = 55 percent) among children and adolescents aged 6 months–17 years.”
This analysis is an estimate based on a relatively small number of doctor visits. These were 4,112 children or adults who were enrolled in the U.S. Influenza Vaccine Effectiveness Network. They all developed a cough and visited a clinic in either Wisconsin, Michigan, Washington, Pennsylvania or Texas.
Every coughing patient was asked whether he or she had received a flu shot. They were then tested for influenza. Roughly one fourth or 1,060 people tested positive for the flu. The number of patients who had received a shot at least two weeks before coming down with symptoms ranged from 38 to 61 percent. That was how the CDC came up with its 45 percent effectiveness number.
Confused? Wait, it gets worse.
How Well Did This Year’s Flu Shot Work for Adults?
Buried fairly deep in the “Interim Estimates of 2019–20 Seasonal Influenza Vaccine Effectiveness — United States” are the data on adults. The CDC reports that this year’s vaccine effectiveness is:
“lower among adults aged 18-49 years.”
The public health authorities note that for this group the effectiveness of the flu shot is only 5 percent against the widely circulating type A H1N1 virus.
In essence, the CDC states that the influenza vaccine did not work (“was not statistically significant”) against the H1N1 type A flu in adults.
The Bottom Line on This Year’s Flu Shot:
In summing up the preliminary data the public health authorities conclude:
“Current influenza vaccines are providing substantial public health benefits; however, more effective influenza vaccines are needed…Influenza antiviral medications remain an important adjunct to influenza vaccination. CDC recommends antiviral treatment for any patient with suspected or confirmed influenza who is hospitalized, has severe or progressive illness, or is at high risk for complications from influenza, including children aged <2 years and adults aged ≥65 years, regardless of vaccination status or results of point-of-care influenza diagnostic testing. Antiviral treatment can also be considered for any previously healthy symptomatic outpatient not at high risk for complications, with confirmed or suspected influenza, if treatment can be started within 48 hours of illness onset.”
In other words, if you come down with the flu, even after getting a flu shot, an antiviral medication might be appropriate.
We are happy that children seem to have been reasonably well protected against this year’s influenza infections. We are disappointed that adults do not appear to have received much, if any, benefit.
Researchers are working on more effective vaccines. We hope that they are successful before next year’s flu season rolls around.
Stay tuned for more details on this year’s flu shot. When the CDC finally publishes the data on VE (vaccine effectiveness) we will fill you in on the details. Hopefully, it will be better than the preliminary data suggest.
How well did this year’s flu shot work for you? Were you protected or did you get the flu anyway? Please share your story in the comment section below.