‘I have heart problems! Should I get the flu vaccine or not?’ This is a question that many people ask their doctors. Doubts about the benefits of vaccination and fears that it may cause cardiovascular complications are common. However, getting vaccinated against the flu can make the difference between having or not having a serious and potentially fatal event! What do we know about the flu? Flu, technically called influenza, is an infection caused by the t ype A and type B influenza viruses . The most common symptoms are fever, tiredness, body aches, cough, sore throat and runny nose. Symptoms can start suddenly and vary in intensity and duration depending on the person. In most cases, the flu is a benign course and self-limiting disease. However, in some cases, particularly in people with chronic illness, the elderly and pregnant women, the outcome can be fatal. It is estimated that more than half a million people die every year from influenza worldwide. Therefore, all measures that can prevent and reduce the risk of complications must be widely implemented . Is the flu vaccine effective? The effectiveness of the flu vaccine is influenced by several individual factors , such as: The age; The presence of chronic diseases; Immune function. Additionally, the ability of viruses to mutate and escape the immunity developed following vaccination is also something that can reduce the effectiveness of the vaccine in an unpredictable way. For this reason, getting the flu vaccine does not guarantee that the disease will not develop. Despite this, the benefit of vaccination not questionable ! On average, the flu vaccine reduces the risk of getting the flu by about 60%! In vaccinated people who still have the flu: The risk of complications is lower; Hospitalization rate is lower; The risk of mortality is around 30% lower. Is the flu vaccine safe? The flu vaccine has been extensively tested and the risk of significant side effects is negligible. The main complications of the vaccine are local reactions in the place of administration and systemic allergic reactions, these with a very low risk. And in people with cardiovascular disease, is the vaccine also effective and safe? Doubts about administering the flu vaccine to people who are at risk of or suffer from heart disease is perhaps one of the biggest myths! In general, the benefits of the vaccine are always greater when there are associated chronic diseases, whether cardiac or not. Regarding the effectiveness of the vaccine, in the presence of cardiovascular disease, the results of the studies are today unquestionable and reveal that: Flu vaccination in patients with established cardiovascular disease reduces the risk of mortality by 25% and the risk of cardiac events by 13%; In patients who had a recent acute myocardial infarction, it was found that the administration of the flu vaccine reduced the risk of mortality by 41% in the 12 months after its administration; In all studies that evaluated the effectiveness of the vaccine in patients with previous heart disease, no increased risk of side effects was identified. Therefore, also in people with cardiovascular diseases, the flu vaccine is considered safe . In summary ... The flu can have potentially fatal complications, and this risk is significantly higher in people who have chronic illnesses, particularly cardiovascular disease, whatever it may be! The vaccine reduces the risk of developing the flu and even when it does occur, the risk of complications is lower! Additionally, if flu vaccination is carried out annually, particularly in the most susceptible people, the probability of death or cardiovascular events is significantly lower when the vaccine is administered! For this reason, there is no doubt: if you have cardiovascular disease, don't miss the opportunity to get the flu vaccine! References: Demicheli V, Jefferson T, Ferroni E, et al. Vaccines for preventing influenza in healthy adults. Cochrane Database Syst Rev 2018;2:CD001269. European Centre for Disease Prevention and Control. Factsheet about seasonal influenza . Fröbert O, Götberg M, Erlinge D, et al. Influenza vaccination after myocardial infarction: a randomized, double-blind, placebo-controlled, multicenter trial. Circulation 2021;144:1476-84. Grohskopf LA, Blanton LH, Ferdinands JM, et al. Prevention and control of seasonal influenza with vaccines: recommendations of the advisory committee on immunization practices - United States, 2022-23 Influenza Season. MMWR Recomm Rep 2022;71:1-28. 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:e019636. Author : José Ferreira Santos Meet the cardiology clinical team from Hospital da Luz network. The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
