Safety and immunogenicity of a live attenuated mumps vaccine: a phase I clinical trial

Abstract

Background: Mumps, a communicable, acute and previously well-controlled disease, has had recent and occasional resurgences in some areas.

Methods: A randomized, double-blind, controlled and multistep phase I study of an F-genotype attenuated mumps vaccine produced in human diploid cells was conducted. A total of 300 subjects were enrolled and divided into 4 age groups: 16-60 years, 5-16 years, 2-5 years and 8-24 months. The groups were immunized with one injection per subject. Three different doses of the F-genotype attenuated mumps vaccine, A (3.5 ± 0.25 logCCID50), B (4.25 ± 0.25 logCCID50) and C (5.0 ± 0.25 logCCID50), as well as a placebo control and a positive control of a licensed A-genotype vaccine (S79 strain) were used. The safety and immunogenicity of this vaccine were compared with those of the controls.

Results: The safety evaluation suggested that mild adverse reactions were observed in all groups. No serious adverse event (SAE) was reported throughout the trial. The immunogenicity test showed a similar seroconversion rate of the neutralizing and ELISA antibody in the 2- to 5-year-old and 8- to 24-month-old groups compared with the seroconversion rate in the positive control. The GMT of the neutralizing anti-F-genotype virus antibodies in the vaccine groups was slightly higher than that in the positive control group.

Conclusions: The F-genotype attenuated mumps vaccine evaluated in this clinical trial was demonstrated to be safe and have effective immunogenicity vs. control.

Trial registration: ClinicalTrials.gov NCT01712906.

Keywords: F genotype attenuated mumps vaccine; Phase I clinical trial; immunogenicity; safety.

Figures

Figure 1. Summary of the trial design. * A dose:3.50 ± 0.25 logCCID50/ml, B dose:4.25 ± 0.25 logCCID50/ml, C dose:5.00 ± 0.25 logCCID50/ml. (A) Adult: 16 y-old~ < 60 y-old. (B) Child: 5 y-old~ < 16 y-old. (C) Preschool: 2 y-old~ < 5 y-old. (D) Infant: 8 mo-old~ < 2 y-old.

Figure 2. Seroconversion rates of serum 28 d after vaccination in C dose, placebo and control groups. Containing individuals (A) 16–60 y old, (B) 5–16 y old, (C) 2–5 y old and (D) 8–24 mo old. Detection of antibody, including the neutralizing antibodies against SP-A virus and S79 virus, and the antibody detected by ELISA. The genotype A vaccine control group was added in the 2–5-y-old and 8–24-mo-old groups. Seroconversion definition: ELISA:An antibody titer > 12 U/ml was considered seropositive. Neutralizing antibody: An antibody titer > 1:4 was considered seropositive.