Study findings suggest that previous vaccination against hepatitis A virus infection does not reliably protect some people with HIV.
Researchers found that more than half of people with HIV who developed HAV infection during an ongoing HAV outbreak in Tennessee had been at least partially vaccinated.
“Complete immunization against hepatitis A requires two doses of a monovalent vaccine or three doses of a combined hepatitis A and hepatitis B vaccine; approximately 90% of vaccinated persons achieve protective antibody levels after a single dose of either product,” Julia Brennan, MS, MPH, a CDC Epidemic Intelligence Service officer in the Tennessee Department of Health, and colleagues wrote in MMWR. “However, persons living with HIV infection might not develop the same level of immunity after hepatitis A virus (HAV) vaccination as do immunocompetent persons.”
Brennan and colleagues sought to determine the frequency at which people infected with HIV who were previously vaccinated against HAV developed HAV infection during the outbreak by reviewing HAV cases reported from Dec. 1, 2017, to Sept. 20, 2018. They checked for HIV status and HAV vaccination using data from case reports, surveillance databases and medical records.
Data showed that among 249 confirmed HAV cases, 11 (4%) occurred among patients with HIV, including six who had received a partial or complete vaccination series before acute infection, all of them men.
According to the study, three of the six had received a monovalent vaccine, including one who completed a two-dose series 3 years before their HIV diagnosis and 7 years before acute HAV infection and one who received both doses 5 years before the onset of HAV infection. The third patient received one dose of HAV vaccine 44 days before he was identified as a sexual contact of a person with acute HAV infection and received postexposure prophylaxis (PEP), including one dose of monovalent vaccine, according to Brennan and colleagues.
The other three patients received either one or two doses of the combined vaccine, the researchers reported.
“Five of six patients initiated vaccination after HIV diagnosis, although all six patients had an indication for routine HAV vaccination that predated HIV diagnoses, including identifying as a man who had sex with men or use of recreational drugs,” Brennan and colleagues wrote.
They noted that current guidelines do not recommend HAV PEP for patients with HIV who have been previously vaccinated against HAV.
“These findings support the consideration by providers to administer IG as PEP for all persons with HIV infection who experience high-risk exposure to a person with HAV infection, regardless of the exposed person’s prior vaccination history or immune status,” the authors concluded.
By Caitlyn Stulpin