Comparable Serologic Responses to 2 Different Combinations of Inactivated Hepatitis A Virus Vaccines in HIV-Positive Patients During an Acute Hepatitis A Outbreak in Taiwan

We evaluated the serologic responses to different 2-dose combinations of the inactivated hepatitis A virus (HAV) vaccines Havrix and Vaqta among human immunodeficiency virus-positive individuals during an acute hepatitis A outbreak in Taiwan. In this 16-month retrospective study, one group received 1 dose of Havrix followed by 1 dose of Vaqta, and another group received 2 doses of Vaqta. The Havrix-Vaqta and Vaqta-Vaqta groups achieved similar seroconversion rates at weeks 28-36 (82.3% and 80.9%, respectively; absolute difference, 1.3% [95% confidence interval {CI}, -6.3%-3.7%]) and week 48 (94.7% and 94.4%, respectively; absolute difference, 0.3% [95% CI, -2.6%-3.2%]), suggesting the interchangeability of different combinations of HAV vaccines. The significantly higher seroconversion rate after the first dose of Vaqta, compared with the dose of Havrix (53.0% vs 32.4%) may provide potential benefits in preventing HAV infection during the outbreak.