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HBV vaccine nonresponders may respond to combined Hep A/B vaccine.

Reuters Health - Sep. 02, 2008
http://www.therapeuticsdaily.com/news/article.cfm?contenttype=sentryarticle&contentvalue=1831583&channelID=31

NEW YORK (Reuters Health) - For the 5% to 10% of adults who fail to mount an adequate response to the standard hepatitis B virus (HBV) vaccine regimen, a double dose of the combined hepatitis A and B vaccine may turn these nonresponders into responders, results of a study from Sweden suggest.

Most guidelines recommend a repeated course of the standard HBV vaccine in people who fail to develop protective levels of antibodies to hepatitis B surface antigen (anti-HBs).

Instead of repeating the standard HBV vaccine regimen in nonresponders, Dr. Kristina Cardell from University Hospital, Linkoping and colleagues opted to administer the combined hepatitis A and B vaccine. Their study involved 48 healthcare workers who failed to respond to the HBV vaccine and 20 control subjects naïve to the HBV vaccine.

After the first dose of the combined vaccine, protective levels of anti-HBs were achieved in 59% of HBV vaccine nonresponders and 10% of control subjects, the investigators report in the August 1 issue of the Journal of Infectious Diseases.
After 3 doses, 95% of prior nonresponders and 100% of controls had developed a response.

"This is most likely explained by the increased dose, a positive bystander effect conferred by the hepatitis A vaccine, or both," Dr. Cardell and colleagues say.

In a commentary, Dr. Helmut M. Diepolder from University of Munich, Germany, writes, "These results are among the best achieved in comparable studies using revaccination with the standard hepatitis B vaccine and are comparable to results from revaccination studies using the pre-S1/S2 vaccine or vaccines with new adjuvants."

"Importantly, the combined vaccine was well tolerated and is, thus, an interesting option to use in hepatitis B nonresponders who are negative for antibodies to hepatitis A virus," Dr. Diepolder adds.