Background:  Revaccination with childhood vaccines among HIV-infected children after immune recovery has resulted in high response rate. However, there is a concern of the rapid waning of antibody over time. To determine the protective antibodies to Hepatitis B(HBV), Japanese encephalitis(JE), measles, mumps, and rubella at 3 years after revaccination in HIV-infected children receiving antiretroviral therapy(ART).

Methods:  HIV-infected children who had no protective antibody levels were revaccinated with HBV, JE or MMR vaccines while receiving ART and had had immune recovery. The levels of protective antibodies were measured at 3 years and compared to those at 6 months after revaccination. Children with antiHBs ≥10 mIU/mL, JE Neutralizing antibody ≥1:10, measles IgG ≥ 320 mIU/mL, mumps IgG ≥ 1:500, and rubella IgG ≥10 IU/mL were defined as having protective antibodies.

Results:  Enrolled were 75 HIV⁺ children with a mean age of 9.7 years (SD2.1) at the time of revaccination. Their mean CD4 percentage at nadir was 5.5 (SD4.7). At the time of revaccination they have had immune recovery (CD4 ≥15%) for a median of 20 months (IQR 16 to 27). The current CD4 percentage was 30.5 (SD6.1). Viral suppression was documented in 97% of children. The protective antibodies were shown in Table 1. There was significantly dropped in proportion of children with protective antibody to HBV at 3 years comparing to 6 months after revaccination (71% vs 96%, P <0.01). Those who had anti-HBV below protective level at year 3 had significant lower antibody titer at month 6 comparing to those with persistent protective antibody [89 (95%CI 49 to 130) vs 5617 (95%CI 3496 to 7738), P<0.01], while age at the time of revaccination, gender, baseline CD4, baseline HIV RNA level, or duration from immune recovery to time of revaccination were not a predictor for antibody loss.

Table 1 Seroprevalence of protective antibodies in HIV-infected children after revaccination

Conclusions:  There were high rate of protective antibodies up to 3 years after revaccination of childhood vaccines in HIV-infected children after received ART. Revaccination program for those children after immune recovery should be considered to ensure protection of common diseases.