Immunogenicity, safety and antibody persistence of a purified vero cell cultured rabies vaccine (Speeda) administered by the Zagreb regimen or Essen regimen in post-exposure subjects.

AIM

To compare the safety, immunogenicity and long-term effect of a purified vero cell cultured rabies vaccine in post-exposure subjects following 2 intramuscular regimens, Zagreb or Essen regimen.

METHODS

Serum samples were collected before vaccination and on days 7, 14, 42, 180 and 365 post vaccination. Solicited adverse events were recorded for 7 d following each vaccine dose, and unsolicited adverse events throughout the entire study period. This study was registered with ClinicalTrials.gov (NCT01821911 and NCT01827917).

RESULTS

No serious adverse events were reported. Although Zagreb regimen had a higher incidence of adverse reactions than Essen regimen at the first and second injection, the incidence was similar at the third and fourth injection between these 2 groups as well. At day 42, 100% subjects developed adequate rabies virus neutralizing antibody concentrations (≥ 0.5IU/ml) for both regimens. At days 180 and 365, the antibody level decreased dramatically, however, the percentage of subjects with adequate antibody concentrations still remained high (above 75% and 50% respectively). None of confirmed rabies virus exposured subjects had rabies one year later, and percentage of subjects with adequate antibody concentrations reached 100% at days 14 and 42.

CONCLUSIONS

Rabies post-exposure prophylaxis vaccination with PVRV following a Zagreb regimen had a similar safety, immunogenicity and long-term effect to the Essen regimen in China.