by Catherine Colquitt, MD
This piece was originally published in the January/February issue of the Tarrant County Physician. You can read find the full magazine here.
In the midst of the worst pandemic in over a hundred years, it’s easy to overlook vaccine-preventable seasonal influenza.
According to the Centers for Disease Control and Prevention, as of December 28, 2020, COVID-19 has already accounted for 336,761 deaths and 19,297,396 cases in the U.S. since its first appearance in early 2020. Tarrant County has reported more than 135,793 confirmed cases (TCPH data) and 1,425 deaths so far (https://covid.cdc.gov.covid-data-tracker). The current percent positivity (percent positive tests/all tests performed) for Tarrant County is a staggering 17 percent (also from CDC COVID Data Tracker).1
For reference, the 1918 influenza pandemic is reported to have killed 21,000,000 people including 549,000 Americans.2
Our most recent prior pandemic, the influenza experience between April 2009 and April 2010, H1N1pdm09, accounted for 60.8 million U.S. cases, 274,304 hospitalizations, and 12,469 U.S. deaths. H1N1 continues to circulate and is still included in the seasonal flu vaccine. A monovalent vaccination produced in response to the H1N1pdm09 pandemic after this strain emerged in 4/2009 wasn’t distributed widely until 11/2009.3
H1N1pdm09 was unique in causing more severe outcomes in younger persons. Approximately 30 percent of persons over 60 in 2009 were thought to have some immunity to H1N1pdm09 conferred by exposure in the past to another H1N1 strain.
As we make our way through the 2020-2021 flu season while in the throes of the highly politicized COVID-19 pandemic, how will we fare at vaccinating Americans against seasonal flu, and will flu vaccination rates provide some hint at public acceptance of, or enthusiasm for, COVID-19 vaccines?
According the CDC’s FluVaxView, during the 2019-2020 flu season, 80.6 percent of healthcare personnel received flu vaccines, with 94.4 percent vaccination in healthcare settings which required it and 69.6 percent in healthcare settings which did not make it mandatory.4
In the U.S., for the 2019-2020 flu season, CDC Influenza data are still preliminary but provide a range in numbers of influenza cases from 39,000,000 to 56,000,000, flu medical visits from 18,000,000 to 26,000,000, flu hospitalizations from 410,000 to 740,000, and flu deaths from 24,000 to 62,000. Even using the highest estimate for flu deaths from last season, COVID-19 deaths have already quadrupled the total number of flu deaths last season (https://www.cdc.gov/flu/about/burden/past-seasons.html).5
However, according to Flu Surv-NET (the Influenza Hospitalization Surveillance Network), the number of influenza-associated hospitalizations from 10/01/2020 to 12/05/2020 only totals 61 in the U.S. thus far (compared with prior seasons this is an unseasonably low number). There is not yet efficacy data for the 2020-2021 seasonal influenza vaccine because of low case counts so far, but most influenza experts expect a mild flu season due to COVID-19 practices of masking, social distancing, hand sanitization, and cough and sneeze hygiene.
As communities struggle to control the catastrophic consequences of COVID-19, getting our flu vaccines and encouraging all of our eligible patients to do the same demonstrates leadership and concern for the most vulnerable among those we serve. Discussing the flu vaccine with our patients also offers context for discussing the COVID-19 vaccines.
2 Epidemiology and Prevention of Vaccine-Preventable Diseases,
13th Edition, p 187
3 https://www.cdc.gov/flu/pandemic-resources/2009-h1n1- pandemic.html
4 https://www.cdc.gov/flu/fluvaxview/hcp- coverage_1920estimates.html.