Comparative Effectiveness of Different Influenza Vaccine Formulations among Patients Undergoing Maintenance Hemodialysis.

KEY POINTS: In patients with kidney failure, enhanced influenza vaccine formulations may provide modestly increased protection versus standard-dose vaccines. This cohort study compared the risk of influenza-like illness, influenza, influenza-related hospitalization, severe influenza, and all-cause mortality by vaccine formulation. Findings support new Centers for Disease Control and Prevention guidelines recommending enhanced influenza vaccine formulations in adults ≥65 years, regardless of kidney failure.

BACKGROUND

Influenza vaccination is recommended to prevent influenza in patients with kidney failure. It remains unclear whether newer, enhanced vaccine formulations are more effective than standard-dose, egg-based, inactivated influenza vaccine (standard-dose vaccine) in patients undergoing maintenance hemodialysis. We sought to compare the effectiveness of five influenza vaccine formulations among patients undergoing hemodialysis.

METHODS

Using the United States Renal Data System database, we performed an active comparator cohort study among adults ≥65 years with kidney failure undergoing hemodialysis (2011/2012-2019/2020 influenza seasons) who received a standard-dose, high-dose, cell culture-based, adjuvanted, or recombinant influenza vaccine within a given season. We compared the risk of influenza-like illness, influenza, influenza-related hospitalization, severe influenza, and all-cause mortality during the influenza season by vaccine formulation. Season-specific risk differences and relative vaccine effectiveness (rVE) were estimated using propensity score-weighted Kaplan-Meier functions, accounting for the competing risk of death (for nonmortality outcomes). We combined the season-specific estimates via a random effects meta-analysis.

RESULTS

578,232 influenza patient-seasons included standard-dose vaccine ( n =372,907), high-dose vaccine ( n =192,880), cell culture-based vaccine ( n =8177), adjuvanted vaccine ( n =3308), or recombinant vaccine ( n =960). Season-specific and meta-analytic estimates were consistent with a modest protective effect of high-dose vaccine versus standard-dose vaccine for influenza (meta-analytic rVE 5.1%; 95% confidence interval [CI], -0.7% to 10.5%), influenza-related hospitalization (meta-analytic rVE 5.5%; CI, -1.8% to 12.3%), and severe influenza (meta-analytic rVE 13.7%; CI, -9.7% to 32.1%), but not influenza-like illness or mortality. Patterns were similar for cell culture-based vaccine versus standard-dose vaccine ( e.g ., meta-analytic rVE for influenza, 18.3%; CI, 2.2% to 31.7%). Estimates for adjuvanted or recombinant versus standard-dose vaccines were imprecise. Quantitative bias analyses did not indicate residual confounding, although some estimates were imprecise.

CONCLUSIONS

Among older adults undergoing hemodialysis, high-dose vaccine and cell culture-based vaccine provided modestly increased protection versus standard-dose vaccine.