Effectiveness of hepatitis A vaccination among people living with HIV in Taiwan: Is one dose enough?

Background: Single dose hepatitis A virus (HAV) vaccine had been proven its efficacy in immunocompetent but not immunocompromised hosts. We aim to investigate the effectiveness of one dose versus 2 doses HAV vaccine among people living with HIV (PLHIV). Method: We conducted a 1:1 single center retrospective case-control study for PLHIV in Northern Taiwan. Case patients were those who received single dose HAV vaccine and controls were those who completed standard 2 doses HAV vaccine. Nationwide campaign of single dose HAV vaccine had been practiced for high risk population including PLHIV and those who had newly diagnosed sexually transmitted diseases. Results: During February 2016 and December 2017, 90 cases received single dose HAV vaccine provided while the other 90 age-matched controls received 2 doses vaccine were enrolled. We found more injection drug users (22.22% vs. 1.11%, p < 0.0001), more co-infection with viral hepatitis C (28.89% vs. 5.56%, p < 0.0001), and history of syphilis infection (56.67% VS 30%, p = 0.0003) in single dose group than 2 doses group. Seroconversion rate at one year was significantly higher in 2 doses group (97.78% vs 56.67%, p < 0.0001). Among single dose group, people with hepatitis B or C virus co-infection (HBV: p = 0.02, aOR: 0.03, 95% CI: 0.002-0.55; HCV: p = 0.002, aOR: 0.22, 95% CI: 0.08-0.58) were less likely to achieve seropositivity, while those who had higher CD4 count at baseline and one year, had better response to vaccine. Conclusion: Two doses HAV vaccine is necessary among PLHIV to achieve sustained seroresponse rather than single dose.