Findings from a large observational study showed that statin use had no impact on influenza vaccine effectiveness in patients aged 45 years or older, researchers reported in Clinical Infectious Diseases.
Study author Fiona J. Havers, MD, MHS, medical officer in the Division of Bacterial Diseases in the CDC’s National Center for Immunization and Respiratory Diseases, called the results “very reassuring.”
“There had been some concern raised in other studies about the association between the influenza vaccine working less well in people taking statins,” Havers told Infectious Disease News.
During three recent influenza seasons, there were an estimated 115,000 to 630,000 hospitalizations and 5,000 to 27,000 deaths associated with influenza in the United States, mostly occurring in adults aged 65 years or older comprised, Havers and colleagues reported. Older adults are also frequently prescribed statins to the reduce the risk for cardiovascular disease, they noted.
To determine the on influenza vaccine effectiveness if used during the vaccination period, Havers and colleagues analyzed data collected from patients in the U.S. Influenza Vaccine Effectiveness Network. The study population were adults aged 45 years or older with a medically attended acute respiratory infection during six influenza seasons from Jan. 1, 2011, to April 14, 2017. Medical and pharmacy records provided the researchers with information on vaccination status, medical history and statin use at the time of vaccination. Vaccine effectiveness was estimated using a test-negative design, according to the study.
The researchers included data from 11,692 patients. Of those, 30% (n = 3,359) were statin users. According to the study, 78% of statin users and 60% of nonusers received the influenza vaccine and 24% (2,806) overall tested positive for influenza. Among statin users, Havers and colleagues determined that the influenza vaccine was 36% effective (95% CI, 22-47). Among nonusers, it was 39% effective (95% CI, 32-45).
According to the study, statin use demonstrated “no significant modification” of influenza vaccine effectiveness. Furthermore, Havers and colleagues said vaccine effectiveness against influenza A(H1N1)pdm09, A(H3N2) and B viruses was similar among statin users and nonusers.
“This study has a number of strengths that some of the other studies didn’t have,” Havers said. “I won’t say this is the last word, but we did find it very reassuring. I think, especially in this population, in older adults, the influenza vaccine is the best way to prevent influenza, which caused 80,000 deaths in the United States last year. This study was reassuring that even if you’re on a statin, you can expect the vaccine will help protect you against influenza.” – by Marley Ghizzone
Disclosures: Havers reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.