Flu Vaccine Performing Well Despite Severity of Season
The flu season this year has been more severe than in previous years, with the number of hospitalizations reaching levels not usually seen until December or January.[0] However, preliminary data from the CDC shows that the flu vaccine has been performing well against the current strain of influenza.[1] The shot proved to be 54% successful in averting visits to the doctor or hospital among individuals aged 65 and below.[2]
It was reported that adults who had received the flu shot were 44% less likely to visit an emergency department or urgent care center and 39% less likely to be hospitalized due to flu illness or complications, compared to 25% vaccine effectiveness at preventing emergency department or urgent care visits and hospitalization during the 2021-2022 season.[3]
Dr. Mark Tenforde, a medical officer in the CDC’s Influenza Division, said, “Vaccination provided substantial protection against inpatient, emergency department and outpatient illness across all ages.”[4]
In addition, the CDC recommends that health care providers continue to administer annual influenza vaccine to persons aged ≥6 months as long as influenza viruses are circulating.[0] This is especially important since there have been 111 influenza-related deaths in U.S. children this season, the most since the COVID-19 pandemic started, with most of the deaths occurring in unvaccinated children.[5]
Analysis of seven hospitals which specialize in treating children indicated a 49% effectiveness rate of the vaccine in preventing severe enough illness that would necessitate hospitalization or emergency medical attention.[6] A study of data from a different monitoring system revealed that the vaccine was 46% effective among individuals aged 18 to 64, and 39% effective for those over 65 who sought medical attention at an emergency room or urgent care clinic.[6]
Overall, the flu vaccine has been 68% effective at preventing hospitalizations in children but has been less protective for seniors this season, according to the CDC.[1] It is important to note that the effectiveness of seasonal flu shots varies by season, as influenza virus subtype and antigenic match with circulating viruses. Therefore, annual influenza vaccination is the best strategy for preventing influenza and its complications.
0. “Interim Estimates of 2022–23 Seasonal Influenza Vaccine Effectiveness — Wisconsin, October 2022–February 2023 …” CDC, 23 Feb. 2023, https://www.cdc.gov/mmwr/volumes/72/wr/mm7208a1.htm
1. “Flu vaccine was 68% effective at preventing hospitalization in children but less protective for seniors this season” CNBC, 22 Feb. 2023, https://www.cnbc.com/2023/02/22/flu-vaccine-cdc-releases-effectiveness-data-for-children-and-seniors.html
2. “Flu vaccine proves effective at preventing illness this season, CDC says” WMUR Manchester, 24 Feb. 2023, https://www.wmur.com/article/flu-vaccine-effective-preventing-illness-cdc/43049392
3. “CDC: This season's flu vaccine provided “substantial protection” across all age groups” KPAX News, 24 Feb. 2023, https://www.kpax.com/news/cdc-this-seasons-flu-vaccine-provided-substantial-protection-across-all-age-groups
4. “Flu Shot Data Underscore ‘Substantial Benefit' Against Flu, Serious Complications: CDC” Medical Daily, 24 Feb. 2023, https://www.medicaldaily.com/flu-shot-data-unerscore-vaccine-effectiveness-against-infection-complications-468223
5. “Early data indicate flu vaccine offered significant protection” Healio, 23 Feb. 2023, https://www.healio.com/news/infectious-disease/20230223/early-data-indicate-flu-vaccine-offered-significant-protection
6. “Flu shot provided relatively robust level of protection this year, data show” STAT, 22 Feb. 2023, https://www.statnews.com/2023/02/22/flu-shot-provided-relatively-robust-level-of-protection-this-year-data-show
