Young adults who received a combined hepatitis A and B vaccination at age 12-15 years maintained immunity after 15 years, making a booster shot unnecessary, according to Dr. Jiri Beran of the Vaccination and Travel Medicine Centre, Hradec Kralove, Czech Republic, and associates.
Study participants received either a 2-dose adult formulation or a 3-dose pediatric formulation. Of the 162 participants included in the 15-year follow-up, all were seropositive for anti–hepatitis A vaccine antibodies, 81.1% of those who received the two-dose vaccination had anti–hepatitis B antibodies, and 81.8% of those who received the three-dose vaccination had anti–hepatitis B antibodies.
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In a subsequent hepatitis B vaccine challenge, all of 8 participants who received the two-dose vaccination and 10 of 11 participants who received the three-dose vaccination developed an anamnastic response. No side effects inconsistent with previous experience were observed.
“The present study confirms that the combined hepatitis A and B vaccine is equally immunogenic and safe in adolescents when administered as the standard three-dose pediatric regimen or as two doses of the adult strength vacciwne,” the investigators said.
Find the full study in Vaccine (doi: 10.1016/j.vaccine.2016.04.033).