Influenza Vaccine Trials Could Give Insights into Testing COVID-19 Interventions

Three ongoing trials studying the cardiovascular outcomes of influenza vaccines could provide insight into testing novel interventions against coronavirus disease 2019 (COVID-19), according to an article published in the Journal of American College of Cardiology.

In addition to the findings of the clinical trials, researchers said seasonal influenza vaccine development and production could inform future efforts at developing and evaluating vaccine strategies for COVID-19. The World Health Organization estimates that as many as 650,000 people die annually from influenza, making it a top 10 cause of death among people of all ages and especially among those with 1 or more comorbidities, such as cardiovascular disease. Because of these risks, clinical guidelines recommend annual vaccinations to reduce the risk of flu-like illness.

Earlier research has found that viral respiratory infections such as influenza and COVID-19 are risk factors for cardiovascular disease, which can also result in higher risks of complications following viral respiratory infections, including increased morbidity, mortality, and health care utilization, according to the current study. The authors noted that although influenza and COVID-19 appear to share many symptoms at the onset, COVID-19 appears to be more contagious.

“Although COVID-19 and other respiratory virus infections are associated with acute myocardial infarction and other cardiovascular events, influenza has the best evidence of a safe vaccine option for cardiovascular risk reduction to date,” said corresponding author Jacob A. Udell, MD, MPH, cardiologist a Women’s College Hospital in Toronto, in a press release. “Several observational and small, randomized studies have suggested that influenza vaccination may serve as a preventative measure against adverse cardiovascular outcomes.”

Three international cardiovascular outcomes trials are currently examining the cardioprotective effects of different influenza vaccine formulations, according to the press release. The Influenza Vaccine to Prevent Adverse Vascular Events trial is a placebo-controlled, randomized clinical trial studying adverse cardiovascular events using the New York Heart Association Functional Class II-IV HF in patients from Asia, the Middle East, and Africa.

The Influenza Vaccination After Myocardial Infarction trial is also a placebo-controlled, randomized clinical trial is also placebo-controlled and randomized, and is testing patients with an ST-elevation myocardial infarction (STEMI) or non-STEMI, or stable coronary artery disease undergoing coronary angiography. Data are being collected from Sweden, Denmark, Norway, the Czech Republic, Scotland, Latvia, Australia, and Bangladesh.

Finally, the third clinical trial, the Influenza Vaccine to Effectively Stop Cardiothoracic Events and Decompensated Heart Failure trial, is being conducted in the United States and Canada. It is the first study of its kind comparing 2 different types of influenza vaccines over several flu seasons, in high-risk cardiovascular patients with a recent history of myocardial infarction or hospitalization for heart failure.

“Three large ongoing influenza vaccine cardiovascular outcome trials have an opportunity to contribute further to our understanding of the underlying comorbidities in these patients that may be driving morbidity and mortality associated with COVID-19 infection,” Udell said in the press release. “These cohorts may also be an opportunity to explore novel infection prevention therapies beyond influenza vaccination in patients that have already volunteered to participate in a respiratory virus vaccine cardiovascular outcome study. While developing new vaccines, we will also definitively learn soon whether influenza vaccination is an effective, low-cost, widely available therapy that reduces cardiovascular risk, which may further help prevent fatal and nonfatal cardiovascular complications of COVID-19.”

REFERENCE

Influenza Vaccine May Provide Roadmap to Prevent COVID-19 in CV Disease Patients [news release]. EurekAlert; October 5, 2020. https://eurekalert.org/pub_releases/2020-10/acoc-ivm100120.php. Accessed January 27, 2021.