EDITORIAL

South African Heart Association: Plea for influenza vaccination

Cardiovascular mortality and morbidity are increased during influenza epidemics, while vaccination has been demonstrated to significantly reduce cardiovascular risk.^[1] It is postulated that infection with influenza causes a systemic inflammatory state, which can trigger adverse cardiovascular events, e.g. coronary syndromes.^[2] In a metaanalysis that included >200 000 patients, influenza vaccination was associated with a 25% risk reduction in all-cause mortality and major adverse cardiovascular events: cardiovascular death, non-fatal stroke and myocardial infarction.^[3] The benefits of vaccination against influenza were confirmed in a recent, multi-centre, randomised trial, which was conducted during four influenza seasons.^[4] Vaccination of patients who underwent a coronary intervention led to a decrease in all-cause mortality, myocardial infarction and stent thrombosis.^[4] The protective effect of influenza vaccination persists for up to 6 months, and while ideally it should be administered prior to the influenza season (most commonly the first week of June), it can still be taken at any time during winter. Influenza vaccination not only lowers the probability of developing infection, but also reduces the severity when established, allowing earlier recovery.

Serious adverse events are infrequent with influenza vaccination; the most commonly reported side-effect being an injection site reaction.^[4,5]

Influenza vaccination is recommended for all patients at high risk, including those with cardiac disease,^[6] and it is supported by the National Institute for Communicable Diseases of South Africa (SA) (NICD) (https://www.nicd.ac.za/wp-content/uploads/2022/05/Influenza-guidelines_-22-April-2022-final.pdf). People who live with 'at-risk individuals' should also be vaccinated. According to the NICD, influenza causes up to 11 000 deaths per year in SA.

The SA Heart Association (SA Heart) wishes to highlight the benefits of annual influenza vaccination, in particular for patients with heart disease or those at risk of heart disease, to cardiologists, medical practitioners and the public, as part of a comprehensive risk reduction strategy for patients with cardiovascular disease.

E Q Klug

Netcare Sunninghill and Sunward Park Hospitals, and Division of Cardiology, Charlotte Maxeke Johannesburg Academic Hospital, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa

P van der Bijl

SA Endovascular, Netcare Kuils River Hospital, Cape Town, South Africa pieter.vanderbijl@gmail.com

References

1. Phrommintikul A, Kuanprasert S, Wongcharoen W, et al. Influenza vaccination reduces cardiovascular events in patients with acute coronary syndrome. Eur Heart J 2011;32(14):1730-1735. https://doi.org/10.1093/eurheartj/ehr004        [ Links ]

2. Corrales-Medina VF, Madjid M, Musher DM. Role of acute infection in triggering acute coronary syndromes. Lancet Infect Dis 2010;10(2):83-92. https://doi.org/10.1016/S1473-3099(09)70331-7        [ Links ]

3. Yedlapati SH, Khan SU, Talluri S, et al. Effects of influenza vaccine on mortality and cardiovascular outcomes in patients with cardiovascular disease: A systematic review and meta-analysis. J Am Heart Assoc 2021;10(6):e019636. https://doi.org/10.1161/JAHA.120.019636        [ Links ]

4. Frobert O, Gotberg M, Erlinge D, et al. Influenza vaccination after myocardial infarction: A randomized, double-blind, placebo-controlled, multicenter trial. Circulation 2021;144(18):1476-1484. https://doi.org/10.1161/CIRCULATIONAHA.121.057042        [ Links ]

5. Smeeth L, Thomas SL, Hall AJ, et al. Risk of myocardial infarction and stroke after acute infection or vaccination. N Engl J Med 2004;351(25):2611-2618. https://doi.org/10.1056/NEJMoa041747        [ Links ]

6. Knuuti J, Wijns W, Saraste A, et al. 2019 ESC Guidelines for the diagnosis and management of chronic coronary syndromes. Eur Heart J 2020;41(3):407-477. https://doi.org/10.1093/eurheartj/ehz425        [ Links ]