In recent years, almost half of all U.S. states have reported outbreaks of person-to-person transmission of hepatitis A virus, especially among people who use drugs, people experiencing homelessness, and men who have sex with men. Infectious Disease News asked
Kelly L. Moore, MD, MPH,
a preventive medicine physician and adjunct associate professor of health policy at Vanderbilt School of Medicine, if HAV vaccination should be recommended for all adults in light of the ongoing outbreaks. Moore chairs the Hepatitis Vaccines Work Group for the CDC’s Advisory Committee on Immunization Practices.
No. Although the HAV vaccine provides safe, effective, long-term protection against HAV and may be given to any adult who wants it, efficient prevention and control of person-to- person outbreaks in the United States depends upon improved implementation of existing recommendations to vaccinate adults at risk, including people who use drugs.
In addition to the populations recommended for HAV vaccination, the CDC advises that any person who wishes to be protected from HAV may be vaccinated. Although childhood immunization rates are high, only a small proportion of at-risk adults have been vaccinated.
The ongoing outbreak that started in 2017 among people who use drugs, men who have sex with men, and people experiencing homelessness has spread primarily along networks of those known to be at risk and their close contacts; the risk to the wider community has remained low. What has worked to close the coverage gap among those at risk is offering vaccination to everyone in settings where they congregate, such as homeless shelters, correctional facilities, drug treatment facilities, emergency rooms and specialized clinics. Even with this focused approach, manufacturers have been challenged to meet the surge in demand. A routine recommendation for HAV vaccination of all adults would divert a finite supply of vaccine, manpower and resources to millions at negligible risk for illness, thanks to clean water and sanitation systems. In the near term, it would worsen the situation in states dealing with ongoing outbreaks by diluting the time, money and effort necessary to vaccinate a high proportion of adults at risk to protect the vulnerable and disrupt transmission channels.
In a world of unlimited human, financial and vaccine resources, I could easily recommend that all adults be vaccinated — after all, the risk for any susceptible person is not zero — but we do not live in that world. The most efficient and effective way to prevent future outbreaks is to leverage our comprehensive childhood immunization infrastructure to fully vaccinate the next generation while investing in sustainable vaccine delivery strategies that make the HAV vaccine routinely and readily available to adults at risk.
Disclosure: Moore reports no relevant financial disclosures.