Hepatitis A Vaccination Required for Herd Immunity in People Experiencing Homelessness or Who Use Dr

Hepatitis A Vaccination Required for Herd Immunity in People Experiencing Homelessness or Who Use Drugs

In the U.S., hepatitis A outbreaks are repeatedly affecting people experiencing homelessness or who use drugs. A 2017-19 Kentucky outbreak primarily among these groups resulted in 501 cases, six deaths. Vaccination efforts likely averted 30 hospitalizations and $490K in costs, but UC San Diego and Oxford researchers say more could have been saved if initiated earlier and faster. They determined herd immunity in these populations requires 77 percent vaccinated, underscoring need for outreach.

The study, published October 18, 2021 in Vaccine, was led by Natasha Martin, DPhil, professor at UC San Diego School of Medicine, and Emmanuelle Dankwa and Christl Donnelly, CBE FMedSci FRS, at University of Oxford.

Pictured: A UC San Diego Health employee is vaccinated against hepatitis A during an outbreak in San Diego, Calif. in 2017. Credit: Erik Jepson/UC San Diego Publications

— Heather Buschman, PhD