Despite the immunomodulatory effects of statins, their use do not appear to modify vaccine effectiveness in adults aged ≥45 years, according to study results published in Clinical Infectious Diseases.
In this study, the authors determined the influence of statin use (simvastatin, atorvastatin, pravastatin, lovastatin, rosuvastatin, and fluvastatin) on influenza vaccine effectiveness in adults with laboratory-confirmed influenza.
Influenza vaccine effectiveness against strains A[H1N1]pmd09, A[H3N2], and B viruses was estimated using a test-negative design and separate estimation models for each specific influenza type. The authors analyzed data from participants within the US Influenza Vaccine Effectiveness Network during 6 influenza seasons (2011–2017).
Participants ≥45 years old with medically attended acute respiratory infection, defined as a new cough lasting ≤7 days, comprised the study cohort. If participants began statin therapy within 30 days of vaccination or after September 1 of the season, or if the participants stopped statin therapy within 30 days of vaccination, then they were excluded from the study.
If participants were not vaccinated, they were excluded if statin therapy began within 30 days of the median vaccination date for that season. Other exclusion criteria were vaccination at <14 days before illness onset, inconclusive real-time reverse-transcription polymerase chain reaction results, influenza testing at >7 days post-symptom onset, or incomplete medical records.
A total of 13,398 participants were enrolled in the study and 1706 of those participants were excluded. Of the remaining participants, 24% tested positive for influenza virus infection.
No significant interaction was found between statin use and influenza vaccination status overall (P =.72), between current season influenza vaccination among participants who were vaccinated in the prior season (P =.70), or among participants who were not vaccinated in the previous season (P =.27).
The authors note several study limitations, which are potential misclassification of statin use due to inadequate pharmacy and medical record data, reported nonadherence to statin prescriptions, and the potential that the study sample size may have failed to represent potentially smaller effects of statins on vaccine effectiveness.
In conclusion, researchers note that “influenza vaccine effectiveness against laboratory-confirmed influenza illness was not affected by current statin use among persons aged ≥45 years. Statin use did not modify the effect of vaccination on influenza when analyzed by type and subtype.”
Disclosures: Some authors declared financial conflicts of interest with this study. Please refer to original reference for a full list of authors’ disclosures.
Havers, FP, Chung JR, Belongia EA, et al. Influenza vaccine effectiveness and statin use among adults in the United States, 2011–2017 [published online October 27, 2018]. Clin Infect Dis. doi: 10.1093/cid/ciy780