Risk of incident gout following exposure to recombinant zoster vaccine in US adults aged ≥50 years.

OBJECTIVE: To assess whether recombinant zoster vaccine (RZV) is associated with an increased risk of new-onset gout among US adults aged ≥50 years. METHODS: We conducted a real-world, retrospective safety study with a self-controlled risk interval (SCRI) design using administrative claims data. We included health plan members aged ≥50 years with RZV exposure, followed by incident gout within 60 days. Days 1-30 following RZV exposure were considered the risk window (RW), and days 31-60 were considered the control window (CW). We estimated the risk ratio (RR) of gout in the RW versus CW, using a conditional Poisson model. The primary analysis estimated the risk of incident gout following any RZV dose. Sensitivity analyses evaluated dose 1- and dose 2-specific risks, risk among patients compliant with recommended dose spacing of 60-183 days, adjustment for seasonality, and restriction to the pre-COVID-19 era (before December 1, 2019). RESULTS: A total of 461,323 individuals received ≥1 RZV dose; we included 302 individuals (mean age 72.5 years; 66 % male) with evidence of new-onset gout within 60 days in SCRI analyses. A total of 153 (50.7 %) individuals had gout events in the RW and 149 (49.3 %) in the CW (RR 1.03; 95 % confidence interval 0.81, 1.29). All sensitivity analyses had consistent results, with no association of RZV with incident gout. CONCLUSION: In a population of US adults aged ≥50 years, there was no statistically significant increase in the risk of gout during the 30 days immediately after RZV exposure, compared with a subsequent 30-day CW.

Risk of incident gout following exposure to recombinant zoster vaccine in US adults aged ≥65 years.

OBJECTIVE: Assess the risk of incident gout following exposure to recombinant zoster vaccine (RZV). METHODS: This case-only, self-controlled risk interval study included a cohort of US fee-for-service Medicare (Part A, B, and D) beneficiaries aged ≥65 years. The exposure was receipt of at least one dose of the two-dose RZV regimen in 2018 or 2019. The risk and control windows were days 1-30 and days 31-60, respectively, following vaccination. Incident gout was defined as the first episode of gout during the risk or control window, with no evidence of gout in the last 365 days. We estimated the relative risk (RR) and 95 % confidence interval (CI) of incident gout in the risk window relative to the control window, using conditional Poisson regression models. Sensitivity analyses included a dose-compliant subanalysis of individuals who received dose 2 60-183 days after dose 1; dose-specific analysis; seasonality adjustment; and COVID-19 adjustment for potential detection bias due to the pandemic. RESULTS: The 1290 RZV-exposed individuals with incident gout were primarily White (86.98 %), male (61.16 %), and aged 70-79 years (55.82 %). The RR of incident gout was 1.00 (95 % CI 0.90, 1.12). In the dose-compliant sensitivity analysis (n = 959 cases of incident gout), the RR of incident gout was 0.99 (95 % CI 0.87, 1.13). The findings were unchanged in the dose-specific, seasonality, and COVID-19 sensitivity analyses. CONCLUSION: The findings suggest that RZV is not significantly associated with an increased risk of incident gout in the Medicare population aged ≥65 years.

Maternal immunization: where are we now and how to move forward?

Pregnancy and the postpartum period are associated with elevated risks to both mother and infant from infectious disease. Vaccination of pregnant women, also called maternal immunization, has the potential to protect pregnant women, foetuses and infants from several vaccine-preventable diseases. Maternal immunoglobulin G antibodies are actively transferred through the placenta to provide passive immunity to new-borns during the first months of life, until the time for infant vaccinations or until the period of greatest susceptibility has passed. Currently, inactivated influenza, tetanus, and pertussis vaccines are recommended during pregnancy in many countries, but other vaccines may also be administered to pregnant women when risk factors are present. Several new vaccines with a specific indication for use during pregnancy are under development (e.g. respiratory syncytial virus and group B streptococcus vaccines). Years of experience suggest that maternal immunization against influenza, tetanus or pertussis has an acceptable safety profile, is well tolerated, effective and confers significant benefits to pregnant women and their infants. This review describes the principles of maternal immunization and provides an update of the recent evidence regarding the use and timing of maternal immunization. Finally, the barriers preventing wider vaccination coverage and the current limitations in addressing these are also described ( Supplementary Material ). Key messages Maternal immunization gives pregnant women greater protection against infectious diseases; induces high levels of maternal antibodies that can be transferred to the foetus; and helps protect new-borns during their first months of life, until they are old enough to be vaccinated. Pregnant women and new-borns are more vulnerable to infectious diseases than the overall population; nevertheless, vaccination rates are often low in pregnant women. This review provides an update of the recent evidence regarding the use and timing of maternal immunization and describes the barriers preventing wider vaccination uptake and the current limitations in addressing these.