LMS President’s Message, October 2019
Tuyen T. Tran, MD, MBA
Influenza – Get Immunized and Immunize Your Patients
Per CDC statistics, life expectancy at birth among U.S. residents increased from 47.3 years in 1900 to 76.8 years in 2000 (62% increase) [1]. Of the contributing factors, the CDC cited vaccinations as one of the top ten public health achievements [2]. Despite this achievement, influenza annually (since 2010) causes between 9.2 – 35.6 million illnesses, 140,000 – 710,000 hospitalizations, and kills 12,000 – 56,000 people (related to post-influenza complications) [3]. Thus, it is imperative for doctors to promote flu vaccinations this fall. Please join KMA’s Focus on Flu campaign to mitigate influenza’s toll on the community.
The best method of combatting season flu is prevention – vaccination. In the U.S., flu season is in the fall and winter (peak late November to March). Thus, CDC recommends vaccinations toward the end of October as it takes about two weeks for the body’s immune system to respond. The Advisory Committee on Immunization Practices (ACIP) recommends for 2018-2019 Influenza Season, vaccinations for all persons aged ≥6 months who do not have contraindications. Children aged 6 months to 8 years require two doses so administer the first dose as soon as the vaccination becomes available, to allow the second dose (which must be administered ≥4 weeks later). The need for revaccination later in the season is not recommended. Women who are or will be pregnant during the influenza season should receive the vaccination. The four updated recommendations include [4]:
1) Vaccine viruses for 2018-2019 include the trivalent influenza vaccines (A/Michigan/45/2015 (H1N1) pdm09-like virus, A/Singapore/INFIMH-16-0019/2016 (H3N2)-like virus, and B/Colorado/06/2017-like virus) and quadrivalent influenza vaccines (the three above and B/Phuket/3073/2013-like virus, Yamagata lineage);
2) LAIV4 (FluMist Quadrvalent) is an option for those whom it is appropriate
3) Persons with a history of egg allergy of any severity may receive any licensed, recommended, and age-appropriate influenza vaccine (IIV, RIV4, or LAIV4)
4) Expansion of the age indication for Afluria Quadrivalent (IIV4) from ≥18 years to ≥5 years and expansion of the age indication for Fluarix Quadrivalent (IIV4) from ≥3 years to ≥6 months.
| Abbreviation conventions for vaccines |
| · IIV = Inactivated Influenza Vaccine
· RIV = Recombinant Influenza Vaccine · LAIV = Live Attenuated Influenza Vaccine · Numerals following letter abbreviations indicate valence
|
The 2017-2018 U.S. flu season was categorized by CDC as “high severity.” Data used to compute the severity included influenza-related outpatient clinic visits, emergency department visits, hospitalization rates, and geographically widespread influenza activity. Accurate assessment of mortality is more difficult. While flu deaths for children are reported to the CDC (180 as of Aug 25, 2018, 80% of these children did not receive a full flu vaccination), flu deaths in adults are calculated indirectly using statistical models that estimate winter-seasonal excess of either pneumonia and influenza or all-cause mortality exceeding the expected baseline mortality. (In adults, the diagnosis of flu is rarely confirmed with laboratory and influenza infection is often cleared prior to the onset of secondary complications that cause a patient’s death.) The predominant strain for the 2017-2018 season was Influenza A (H3N2). The overall vaccine effectiveness against both influenza A and B viruses in 2017-2018 was 40%. (The vaccine reduced a person’s overall risk of having to seek medical care by 40%.) [5]
What is the forecast for the 2018-2019 flu season? Although we do not know the answer to this question, the more important point is that we can impact flu’s morbidity and mortality. Last year’s 40% vaccine effectiveness translated to a measurable reduction in medical visits, hospitalizations, and deaths. Hopefully, this year’s vaccine is more effective. Please join KMA’s Focus on Flu and promote the flu vaccination!
References
[1] National Center for Health Statistics. Health, United States, 2010: with special feature on death and dying. Hyattsville, MD: CDC, National Center for Health Statistics, 2011. Available at http://www.cdc.gov/nchs/hus.htm. Accessed May 16, 2011.
[2] Ten great public health achievements — United States, 2001–2010. MMWR Morb Mortal Wkly Rep 2011;60:619-23.
[3] Rolfes MA, Foppa IM, Garg S, Flannery B, Brammer L, Singleton JA, et al. Estimated Influenza Illnesses, Medical Visits, Hospitalizations, and Deaths Averted by Vaccination in the United States. 2016 Dec 9. Available at: https://www.cdc.gov/flu/about/disease/201516.htm(https://www.cdc.gov/flu/about/disease/2015-16.htm). Accessed Sep 17, 2018.
[4] Grohskopf LA, Sokolow LZ, Broder KR, Walter EB, Fry AM, Jernigan DB. Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices—United States, 2018–19 Influenza Season. MMWR Recomm Rep 2018;67(No. RR-3):1–20. DOI: http://dx.doi.org/10.15585/mmwr.rr6703a1.
[5] CDC. Summary of the 2017-2018 Influenza Season. CDC. 2018. Available at: https://www.cdc.gov/flu/about/season/flu-season-2017-2018.htm. Accessed Sep 17, 2018.
