Revaccination Can Increase Response Rates, Hepatitis B Protection

By Marilynn Larkin

NEW YORK (Reuters Health) - Revaccinating healthy non-responders with Fendrix or HBVaxPro-40 resulted in significantly more responders to hepatitis B vaccination, a randomized controlled superiority trial showed.

"The results of this trial finally provide an evidence-based rationale for the optimal management of adults who were not protected against hepatitis B after vaccination,'" Dr. Stijn F H Raven of the Regional Public Health Service West Brabant in Breda, Netherlands told Reuters Health by email.

"In this trial, we demonstrated that two vaccines were better in inducing protective immunity in non-responders," he said. "However, as these vaccines are not registered for use in healthy adults, we recommend an expansion of the indication for nonresponders."

As reported online October 16 in The Lancet Infectious Diseases, Dr. Raven and colleagues randomly assigned 480 adults from 16 Dutch centers to Twinrix, HBVaxPro-40, Fendrix, or a control group. Participants' mean age was about 45, about 45% were women, and about 45% had baseline anti-HBs titers of <1 IU/L.

The inclusion criterion was vaccine nonresponse after one initial standard series of three HBV vaccinations at months 0, 1, and 6, with either HBVaxPro-10 or Engerix-B. The primary endpoint was the proportion of responders with an anti-HBs titer of 10 IU/L or more, four weeks to three months after completion of a revaccination series given at months 0, 1, and 2.

The intervals between vaccine doses and titer measurement after completion of the primary and revaccination series were similar in all the groups, as were rates of completion of the full vaccination series.

At three months, the percentage of responders was 67% in the control group, 80% in the Twinrix group, 83% in the HBVaxPro-40 group, and 87% of 124 in the Fendrix group.

Compared with controls, the percentage of responders was superior for the HBVaxPro-40 group (adjusted difference 21.6%) and the Fendrix group (26.3%), but not the Twinrix group (25%). One serious adverse event - herpes zoster ophthalmicus - occurred in the Fendrix group that was not attributed to the vaccine.

Dr. Raven said, "The results of this trial could be used to revise guidelines on the management of revaccination and could also result in a reduction in the number of revaccinations given."

"To reduce the burden of disease for hepatitis B, the implementation of effective infant vaccination programs against hepatitis B is very important," he added. "The younger a person is vaccinated, the better the protective response. Infant vaccination programs have resulted in a significant decrease in the prevalence of HBV infection and in the incidence of liver cancer and will hopefully result in the disappearance of the 'nonresponder' in the next decades."

In a related editorial, authors from the University of Paris note, "We would like to underline that these results will have to be taken into consideration in the light of future studies on a vaccine registered in 2017 (Heplisav-B), which uses a synthetic cytosine phosphoguanine oligonucleotide (CpG 1018) derived from bacterial DNA, thought to stimulate the immune system through activation of the Toll-like receptor 9 pathway...and other experimental HBV vaccines, which might be able to overcome non-response after primary HBV vaccination."

SOURCE: https://bit.ly/36jOjeZ and https://bit.ly/2MZs5Hj

Lancet Infect Dis 2019.

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