INFLUENZA vaccination has been associated with a significant decline in risk for major cardiovascular events. The study, conducted by Fatemeh Omidi, Shahid Beheshti University of Medical Sciences, Tehran, Iran, and colleagues, reported a greater than 20% reduced risk in cardiovascular death following influenza vaccination. The researchers wanted to conduct an updated and comprehensive review on the associations between influenza vaccine and cardiovascular disease (CVD) outcomes.
Omidi and colleagues performed both a systematic review and a meta-analysis of five studies, covering 9,059 patients who either received a standard influenza vaccination (n=4,529), or a placebo (n=4,530).
There were 517 incidents of major cardiovascular events in patients who received the influenza vaccine, and 621 incidents in patients who had received the placebo (risk ratio [RR]: 0.7; 95% confidence interval [CI]: 0.55–0.91). There was also a risk reduction for myocardial infarction (RR: 0.74; 95% CI: 0.56–0.97) and cardiovascular death events (RR: 0.67; 95% CI: 0.45–0.98) in patients who had been vaccinated. The study also suggested influenza infections could play a role in CVDs by weakening the immune system and increasing susceptibility to secondary infections, as well as causing systemic inflammations that contribute to the progression of CVDs.
The researchers involved in the review and analysis concluded that their findings “underscore the potential impact of influenza vaccination in safeguarding against adverse cardiovascular outcomes among vulnerable patient populations.” However, it was noted that further research was still necessary to understand what the specific mechanism behind the association between influenza infections and CVDs is, and to explore the long-term effects of influenza vaccines on cardiovascular health.
