286. Hepatitis B Vaccine Compliance: Comparing 2-Dose and 3-Dose Vaccines

BACKGROUND: Less than 1 in 3 US adults who initiated the 3-dose (0, 1, 6 months) hepatitis B vaccine series have completed it. HepB-CpG (Heplisav-B; Dynavax) is a new licensed adjuvanted vaccine that requires only 2 doses (0, 1 month). As part of a cluster study performed at Kaiser Permanente Southern California, we compared compliance with second dose and series completion for HepB-CpG vs. comparator vaccine (Engerix-B; GlaxoSmithKline) recipients. METHODS: The cohort included adults not on dialysis who received their first dose of hepatitis B vaccine in family or internal medicine departments from 8/7/2018 to 2/1/2019. Second dose compliance was assessed for the full cohort, but series completion was assessed for a subset vaccinated from August 7, 2018 to September 30, 2018 to allow at least 6 months’ follow-up. Compliance rates were estimated using the Kaplan Meier method. Adjusted hazard ratios (aHR) were estimated using Cox proportional hazard regression with robust variance to account for within medical center correlation, adjusting for age, race/ethnicity, census block income and education, prior healthcare utilization, and factors that trigger alerts for hepatitis B vaccination (diabetes and testing for sexually transmitted infections). RESULTS: There were 6500 HepB-CpG and 7733 comparator vaccine recipients (1,442 and 2,604 prior to September 30, 2018). Rates of second dose compliance at 60 days were 32.9% for HepB-CpG and 29.1% for comparator vaccine, and rates of series completion at 210 days were 56.9% and 20.6%. There was no significant difference in second dose compliance (aHR 1.14, 95% CI: 0.91, 1.47), but HepB-CpG recipients were 5 times more likely to complete the series (aHR 5.17; 95% CI: 3.84, 6.98). Second dose compliance and series completion were significantly less likely among Blacks compared with Whites and significantly more likely among Asians, adults ≥60 years compared with those < 30 years, and adults living in census blocks with a median annual income of $40,000–69,000 compared with < $40,000. CONCLUSION: Overall, second dose compliance was similar, but series completion was better for HepB-CpG recipients than comparator vaccine recipients, suggesting that the 2-dose vaccine could lead to improvements in coverage and protection against hepatitis B virus. DISCLOSURES: All authors: No reported disclosures.