It was an interesting couple of weeks for viral hepatitis vaccines. A potential vaccine for Hepatitis C appears to be on the horizon, and China announced it has approved a vaccine for use for hepatitis E virus (HEV).
What does this mean if you have hepatitis B? I’m not sure. If you are living with HBV, it is clear that it is best to avoid coinfection with another hepatitis virus or infectious agent. Coinfection will likely hasten liver disease progression and increase the risk for liver cancer. At this time, the hepatitis A vaccine is recommended for those who are infected with HBV in order to avoid additional stress to the liver. Please keep in mind that the mode of transmission is the same for HBV and HCV, but is different for HAV and HEV. It’s important to keep your viral hepatitis ABC’s straight!
Hepatitis E is a self-limiting disease, which is shed in the feces and transmitted via contaminated water and food – very much like HAV. Although HEV is an acute infection like hepatitis A (HAV), it has about a 3% overall mortality rate and a much higher rate among pregnant women, and solid organ transplant recipients. It predominantly affects those between the ages of 15 and 40 years. HEV is endemic in Central and South-East Asia, North and West Africa, Mexico and developing nations where there may not be access to clean water and proper sanitation and hygiene. At this time, it is not prevalent in the U.S., but we are a traveling nation, and it’s something to think about when traveling abroad.
The HEV vaccine, developed by Xiamen University and Xiamen Innovax Biotech Co. Ltd. is a three-shot series : shot one followed one month later by shot 2, followed by shot 3 six-months after the third shot. The phase III trial results were found to be well tolerated and safe for the general adult population. This would make the HEV vaccine a good choice for travelers in endemic areas who can receive adequate protection with a 2-shot series in one month.
However, these results for the phase III study were for the general population only and did not include children, adults over 65 years, pregnant women and those living with chronic liver diseases such as HBV or HCV. If you are infected with HBV, it would make sense to be vaccinated against a virus that can cause additional harm to the liver, but at this time, additional research needs to be done ensuring the vaccine will benefit those living with hepatitis B or C.