Injection Drug Users Can Benefit from a Partially Effective Hepatitis C Vaccine

A hepatitis C virus (HCV) vaccine could dramatically reduce the transmission of the virus among injection drug users, even without achieving sterilizing immunity, according to a recently-published study.

Although vaccinations are available for hepatitis A and hepatitis B, HCV does not yet have an effective vaccine on the market.

The study, published in Science Translational Medicine, employed mathematical modeling to investigate transmission probabilities relative to HCV RNA titers of needle/syringe-sharing donors. The researchers simulated the sharing of 2 types of syringes fitted with needles that retain either large or small amounts of fluid after expulsion.

Using data from individuals who had been infected or reinfected with the virus, the researchers estimated the transmission risk between injection drug users, accounting for syringe type, rinsing, and sharing frequency.

According to the findings, an injection drug user who shared a syringe/needle with an individual who was infected with HCV would have a greater than 90% of contracting the virus after 6 months, assuming sharing episodes occurred every 7 days. However, if the user had been vaccinated with an effective HCV vaccine, the transmission risk would decrease between 1% and 25%, the researchers estimated. The percentage of decreased risk would depend on the type of needle used and HCV titer, they noted.

“Our findings suggest that a hepatitis C vaccine would be an essential part of a comprehensive prevention strategy to meet the World Health Organization’s goal of eradicating hepatitis C by 2030,” study co-author Scott Cotler, MD, head of Loyola’s division of hepatology and a professor in the department of medicine of Loyola University Chicago Stritch School of Medicine, said in a press release.

To eliminate HCV worldwide, the researchers wrote that methods need to combine the use antivirals with an HCV vaccine and harm-reduction measures, such as needle-syringe exchange programs, opioid substitution therapy, and behavioral counseling.

The researchers concluded that HCV transmission among individuals sharing syringes could be reduced through vaccination, even if the vaccine is only partially effective.

Reference

Major M, Gutfraind A, Shekhtman L, et al. Modeling of patient virus titers suggests that availability of a vaccine could reduce hepatitis C virus transmission among injecting drug users. Science Translational Medicine. 2018. Doi: 10.1126/scitranslmed.aao4496

Hepatitis C vaccine could dramatically reduce transmission in people who inject drugs [news release]. Loyola University Health System. https://eurekalert.org/pub_releases/2018-07/luhs-hcv071018.php. Accessed July 12, 2018.