Hepatitis B Vaccine in Healthy Adults: Effect of Sex and Age, Two Protocols for Non-Responding Adults

Objective: To evaluate in non-immunocompromised adults not vaccinated against HBV (Hepatitis B virus), the response rate to vaccination according to standard protocol (SP) (0, 1, 6 months) and response rate in non-responders subjected to two protocols. Materials And Methods: 192 employees in a Hospital located in Beirut, average age of 44.3, not previously vaccinated, non-immuno compromised, are vaccinated by Engerix B 20 mcg/1ml according to the SP. Non-responders to this protocol are divided into two subgroups. The first one receives a single booster dose 4 months after the end of the SP, and those who remains unresponsive receives a double booster dose 2 years later. The second one receives only one double booster dose 2 years after the SP. Results: The rate of positive immune response after vaccination using the SP is 145/192 (75.5%). 28 non-responder's individuals receives 4 months later a booster dose; the positive response rate is 9/28 (32.14%). The 19 non-responders individual R1 receives a double booster at 2 years with a positive response rate of7/18 (36.84%). The positive response in this subgroup is 57.14%. Non-responders formed by 19 individuals, are boosted after 2 years. Their positive response rate is 63.16%. 19/192 (9.9%) of the individuals do not respond to any protocols. Female gender and advanced age are two factors that diminish the response to vaccination. Conclusion: A booster dose at 2 years gives a better immunity than a simple reminder at 4 months, and is similar to the protocol using a booster at 4 months followed by a second one after 2 years.