Purpose of Review To better understand the impact of obesity and cardiovascular diseases on influenza A infection. Recent Findings This infection could have detrimental outcomes in obese patients with cardiovascular diseases, such as an increased risk, length of hospitalization, disease severity, morbidity, and mortality. Nevertheless, there also might be some cardioprotective benefits associated with influenza vaccination, such as a reduced mortality, hospitalization, and acute coronary syndromes, in patients with coronary heart disease and/or heart failure. Summary Obesity negatively impacts immune function and host defense. Recent studies report obesity to be an independent risk factor for increased morbidity and mortality following infection. Obese patients might need special considerations in the treatment; however, there is not enough evidence to fully comprehend the mechanisms behind the reduced immunocompetence when influenza A infection occurs. Future studies should focus on special consideration treatments when the patients have not been vaccinated and have cardiovascular diseases. Keywords Obesity . Influenza . Cardiovascular disease . Cardioprotective effects of vaccination . Influenza vaccine This article is part of the Topical Collection on Metabolism in Tropical Medicine