Does influenza vaccination reduce the risk of COVID-19? Case-control study in a Primary Care center during the year 2020

e202310087

Authors

  • Lluís Cuixart Costa Médico especialista en Medicina Familiar y Comunitaria; CAP Roger de Flor; EAP Dreta Eixample. Barcelona. España.
  • Nariman Chahboun El Messaoudi Médica Interna Residente de 4º año de Medicina Familiar y Comunitaria; CAP Roger de Flor; EAP Dreta Eixample. Barcelona. España.

Keywords:

COVID-19, Flu vaccines, Primary Care

Abstract

BACKGROUND // There are controversies regarding the effect of the influenza vaccine on the risk of suffering from COVID-19. The aim of this paper was to compare the risk of suffering from COVID-19 between vaccinated and unvaccinated patients against influenza.
METHODS // A retrospective case-control study of patients assigned to an urban CAP (coverage: 44,564 inhabitants) was carried out during 2020. Patients with diagnostic confirmation of COVID-19 (ART, PCR or serology) were defined as cases, and those who have not had said infection, selected by simple random sampling, were defined as controls. The case/control ratio was 1:1. The data sources used were the Khalix health data registry databases and the computerized medical record (E-cap). Data were analyzed with a multivariable logistic regression model.
RESULTS // A total of 4,320 patients were included in the study: 2,160 cases (50%) and 2,160 controls. 18% of the cases and 14.3% of the controls were vaccinated against influenza [OR=1.3 (95% CI: 1.2-1.5; p=0.001)]. Multivariate analysis showed that in patients under eighty years of age, there were no differences between vaccinated and unvaccinated patients [OR=1.02 (95% CI: 0.8-1.3; p=0.8)]; while in those over eighty years of age, there was a lower risk of presenting COVID-19 in vaccinated patients [OR=0.4 (95% CI: 0.3-0.7; p<0.001)].
CONCLUSIONS // The adjusted model shows that at ages above than 80 years, flu-vaccinated patients have decreased risk of COVID-19 with statistical significance.

Downloads

Download data is not yet available.

References

WHO Coronavirus Disease (COVID-19) Dashboard. Disponible en: https://covid19.who.int/. Consultado en septiembre de 2022.

Huang C, Wang Y, Li X, Ren L, Zhao J, Hu Y et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet. 2020; 395(10223):497-506. DOI: https://dx.doi.org/10.1016/S0140-6736(20)30183-5

Cowling BJ, Fang VJ, Nishiura H, Chan K-H, Ng S, Ip DKM et al. Increased Risk of Noninfluenza Respiratory Virus Infections Associated With Receipt of Inactivated Influenza Vaccine. Clin Infect Dis. 2012; 54(12):1778-1783. DOI: https://dx.doi.org/10.1093/cid/cis307

Wolff GG. Influenza vaccination and respiratory virus interference among Department of Defense personnel during the 2017-2018 influenza season. Vaccine. 2020; 38(2):350-354. DOI: https://dx.doi.org/10.1016/j.vaccine.2019.10.005

Consortium EBMPHET. COVID-19 Severity in Europe and the USA: Could the Seasonal Influenza Vaccination Play a Role? SSRN Journal. 2020.

Salem ML, El-Hennawy D. The possible beneficial adjuvant effect of influenza vaccine to minimize the severity of COVID-19. Med Hypotheses. 2020; 140:109752. DOI: https://dx.doi.org/10.1016/j.mehy.2020.109752

Mao H, Tu W, Qin G, Law HKW, Sia SF, Chan P-L et al. Influenza Virus Directly Infects Human Natural Killer Cells and Induces Cell Apoptosis. J Virol. 2009; 83(18):9215-9222. DOI: https://dx.doi.org/10.1128/JVI.00805-09

Bekkat-Berkani R, Wilkinson T, Buchy P, Dos Santos G, Stefanidis D, Devaster JM et al. Seasonal influenza vaccination in patients with COPD: a systematic literature review. BMC Pulm Med. 2017; 17(1):79. DOI: https://dx.doi.org/10.1186/s12890-017-0420-8

Marín-Hernández D, Schwartz RE, Nixon DF. Epidemiological evidence for association between higher influenza vaccine uptake in the elderly and lower COVID-19 deaths in Italy. J Med Virol. 2021; 93(1):64-65. DOI: https://dx.doi.org/10.1002/jmv.26120

Amato M, Werba JP, Frigerio B, Coggi D, Sansaro D, Ravani A et al. Relationship between Influenza Vaccination Coverage Rate and COVID-19 Outbreak: An Italian Ecological Study. Vaccines (Basel). 2020; 8(3):535. DOI: https://dx.doi.org/10.3390/vaccines8030535

Fink G, Orlova-Fink N, Schindler T et al. Inactivated trivalent influenza vaccine is associated with lower mortality among Covid-19 patients in Brazil [e-pub ahead of print]. BMJ Evid Based. Med. DOI: https://dx.doi.org/10.1136/bmjebm-2020-111549. Consultado 26 febrero, 2021.

Del Riccio M, Lorini C, Bonaccorsi G, Paget J, Caini S. The Association between Influenza Vaccination and the Risk of SARS-CoV-2 Infection, Severe Illness, and Death: A Systematic Review of the Literature. Int J Environ Res Public Health. 2020; 17(21):7870. DOI: https://dx.doi.org/10.3390/ijerph17217870

Lisewski AM. Association between Influenza Vaccination Rates and SARS-CoV-2 Outbreak Infection Rates in OECD Countries. SSRN Journal. 2020 . DOI: https://dx.doi.org/10.2139/ssrn.3558270

Zanettini C, Omar M, Dinalankara W, Imada EL, Colantuoni E, Parmigiani G et al. Influenza Vaccination and COVID19 Mortality in the USA. MedRxiv. 2020. DOI: https://dx.doi.org/10.1101/2020.06.24.20129817

Conlon A, Ashur C, Washer L, Eagle KA, Hofmann Bowman MA. Impact of the influenza vaccine on COVID-19 infection rates and severity. Am J Infect Control. 2021;49(6):694-700. DOI: https://dx.doi.org/10.1016/j.ajic.2021.02.012

Published

2023-10-24

How to Cite

1.
Cuixart Costa L, Chahboun El Messaoudi N. Does influenza vaccination reduce the risk of COVID-19? Case-control study in a Primary Care center during the year 2020: e202310087. Rev Esp Salud Pública [Internet]. 2023 Oct. 24 [cited 2024 Nov. 23];97:9 páginas. Available from: https://ojs.sanidad.gob.es/index.php/resp/article/view/167