OBJECTIVE: Preliminary assessment of rabies virus neutralizing activity, safety and immunogenicity of a recombinant human rabies antibody (NM57) compared with human rabies immunoglobulin (HRIG) in Chinese healthy adults. METHODS: Subjects were randomly (1:1:1) allocated to Groups A (20 IU/kg NM57), B (40 IU/kg NM57), or C (20 IU/kg HRIG). One injection was given on the day of enrollment. Blood samples were collected on days -7 to 0 (pre-injection), 3, 7, 14, 28, and 42. Adverse events (AEs) and serious AEs (SAEs) were recorded over a period of 42 days after injection. RESULTS: All 60 subjects developed detectable rabies virus neutralizing antibodies (RVNAs) (> 0.05 IU/mL) on days 3, 7, 14, 28, and 42. The RVNA levels peaked on day 3 in all three groups, with a geometric mean concentration (GMC) of 0.2139 IU/mL in Group A, 0.3660 IU/mL in Group B, and 0.1994 IU/mL in Group C. At each follow-up point, the GMC in Group B was significantly higher than that in Groups A and C. The areas under the antibody concentration curve over 0-14 days and 0-42 days in Group B were significantly larger than those in Groups A and C. Fifteen AEs were reported. Except for one grade 2 myalgia in Group C, the other 14 were all grade 1. No SAEs were observed. CONCLUSION The rabies virus neutralizing activity of 40 IU/kg NM57 was superior to that of 20 IU/kg NM57 and 20 IU/kg HRIG, and the rabies virus neutralizing activity of 20 IU/kg NM57 and 20 IU/kg HRIG were similar. Safety was comparable between NM57 and HRIG.
Adult ; Antibodies, Neutralizing ; Antibodies, Viral ; Data Collection ; Humans ; Rabies/prevention & control* ; Rabies Vaccines/adverse effects* ; Rabies virus/genetics*

Post-exposure prophylaxis (PEP) has proved to be the most important measure for rabies prevention and control. There is little information regarding adverse reactions to the Essen and 2-1-1 regimens in preschool children (aged 0-6). We reexamined the outcomes of 1,109 preschool children who were vaccinated using SPEEDA under the Essen regimen between January 2011 and December 2012 and 1,267 preschool children under the 2-1-1 regimen between January 2013 and December 2014. We find that, in preschool children, the febrile reaction after the first 2-dose injection in the 2-1-1 regimen was significantly higher than that induced by the first 1-dose in the Essen procedure. Thus, we recommend that the Essen regimen should still be used for rabies PEP in preschool children.
Child ; Child, Preschool ; Germany ; Humans ; Infant ; Post-Exposure Prophylaxis ; standards ; Rabies ; prevention & control ; Rabies Vaccines ; adverse effects ; Vaccination ; adverse effects

To investigate the phenotypic characteristics of the strain of the rabies virus CTNCEC25, the strain of the China rabies virus CTN-1 adapted to primary chicken embryo cells (CECs), Vero cells, and mouse neuroblastoma N2a cells was inoculated with CTNCEC25 and parental CTN-1 strains to explore the cytopathic effect (CPE) and growth kinetics of CTNCEC25 on cultured cells. To determine the pathogenicity of CTNCEC25, suckling mice, adult mice, guinea pigs and rabbits were inoculated with CTNCEC25 via the intracerebral route and their survival monitored every day. Furthermore, the CTNCEC25 strain was passed serially in CECs for 20 passages and then 3 passages in the brains of suckling mice to determine phenotypic stability. CTNCEC25 achieved similar growth kinetics in Vero cells and N2a cells compared with parental CTN-1, but CTNCEC25 replicated more efficiently in CECs than the CTN-1 strain with a titer 72 h after infection reaching 10(7.5-7.6) FFU/mL, which was significantly higher than the 10(5.8) FFU/mL achieved by its parental strain, CTN-1. Moreover, CTNCEC25 induced apparent CPE in Vero cells, CECs and N2a cells. Analyses of intracerebral inoculation demonstrated that CTNCEC25 was attenuated profoundly in adult mice and was completely apathogenic to guinea pigs and rabbits, though it caused death in suckling mice. The CTNCEC25 strain proliferated steadily after serial passage in CECs and the brains of suckling mice, and remained avirulent in adult mice. These results suggest that CTNCEC25 is a highly attenuated and genetically stable strain of the rabies virus. CTNCEC25 replicated stably and efficiently in cultured cells and achieved high titers, so it could be a promising and safe vaccine strain for rabies prevention in China.
Animals ; Cell Line ; Cercopithecus aethiops ; China ; Guinea Pigs ; Humans ; Mice ; Rabbits ; Rabies ; virology ; Rabies virus ; genetics ; growth & development ; pathogenicity ; Serial Passage ; Viral Vaccines ; adverse effects ; genetics ; Virulence

OBJECTIVETo observe the safety and efficacy of lyophilized purified human rabies vaccine CTN-Vero RV, CTN strain produced in Vero cells.

METHODS450 healthy volunteers were divided into two groups, with 300 of them receiving CTN-Vero-RV (rabies vaccine for human use made in Vero cells with CTN strain) while 150 of them receiving PVRV to serve as control group. All the subjects were immunized on days 0, 3, 7, 14 and 28 at deltoid muscle respectively. Local and systemic reactions were observed and sera were collected for neutralizing antibody testing using RFFIT. 365 and 730 days after the first dose, sera from the 212 and 176 subjects of the studied group while 97 and 80 subjects from the control group were collected to test for neutralizing antibody.

RESULTSNo severe local or systemic reactions were observed after immunization was performed in the two groups. On days 3, 7, 14, 28 and 365 after the first dose, the antibody positive rates appeared to be 2.35%, 80.78%, 100.00%, 100.00%, 98.58% and 73.30% in the study group and 4.00%, 87.20%, 100.00%, 100.00%, 97.94% and 76.25% in the controls respectively. On day 0, 3, 7, 14, 28, 365 and 730, GMT of the neutralizing antibody level were 0.12, 1.01, 9.83, 12.61, 3.68 and 2.81 IU/ml in the study group while 0.13, 1.18, 10.24, 11.61, 4.18 and 1.92 IU/ml were seen in the control group respectively. There were no significant differences in both antibody positive rates and GMT between the two groups on days 3, 7, 14, 28, 365 or 730 (P > 0.05).

CONCLUSIONCTN-Vero-RV was safe and effective as well as could generate a persistent immune response.

Adolescent ; Adult ; Aged ; Animals ; Antibodies, Neutralizing ; blood ; Antibodies, Viral ; blood ; Cercopithecus aethiops ; Child ; Child, Preschool ; Female ; Freeze Drying ; Humans ; Male ; Middle Aged ; Rabies Vaccines ; adverse effects ; immunology ; Vaccination ; adverse effects ; Vero Cells ; Young Adult