For people living with HIV (PLHIV) who have not had a serological response to the “conventional” hepatitis B virus (HBV) vaccine adjuvanted with aluminum salts (HepB-Alum), a therapeutic alternative becomes clearer. A major challenge given that chronic hepatitis B, despite available vaccines and treatments, affects more than 254 million people; in 2022, the World Health Organization deplores 1.2 million new infections.
The BeeHive international phase 3 clinical trial, bringing together 561 PLHIV on antiretroviral therapy and non-responders to the “conventional” vaccine, compared the immune response of 3 doses of a HepB-Alum vaccine to 2 and 3 doses of a vaccine adjuvanted with cytosine phosphoguanine (HepB-CpG).
Seroprotection obtained more quickly
The results, published in the Jamareport significant superiority of the HepB-CpG vaccine at two (administered at 0 and 4 weeks) or three doses (administered at 0, 4 and 24 weeks). Seroprotection was achieved for 93.1% of people with a two-dose regimen and 99.4% with three doses (antibody titer at 12 and 28 weeks respectively). For people who received 3 doses of the HepB-Alum vaccine, only 80.6% had a sufficient immune response.
Not only is seroprotection greater with two or three doses of HepB-CpG vaccine, but it also occurs more quickly in higher proportions: at 12 weeks for more than 90% of patients compared to just over 60% with the HepB vaccine. -Alum. A result of interest since PLHIV are using less and less antiretroviral therapies containing tenofovir, which has antiviral activity against HBV.
Check long-term immune response
In an editorial published in the JamaIvan Hung, infectious disease specialist in Hong Kong and Anna S. Lok, hepatologist at the University of Michigan, recall that the immune response is among the main obstacles to reducing the incidence of hepatitis B virus infections. “Vaccines have suboptimal effectiveness in people with diabetes, obesity, smokers and immunocompromised people (HIV, chronic kidney disease, etc.)”. Thus, complete and rapid seroprotection would be particularly beneficial in populations other than PLHIV.
The authors of the editorial nevertheless qualify: the trial evaluated the short-term immune response, it is therefore necessary to study its evolution in the longer term to confirm the interest of this vaccine. They add: “Even though the HepB-CpG vaccine is more immunogenic, a small percentage of immunocompromised patients fail to achieve seroprotection. Efforts must continue to explore other strategies such as methods of administration or the combination of new adjuvants with several HBV antigens..
In France, the available vaccines are adjuvanted with aluminum salts, but the European Medicines Agency issued a favorable opinion on the marketing of the HepB-CpG Heplisav-B vaccine (from the Dynavax laboratory) on December 10, 2020.
