Immunogenicity of BCG-CpG-DNA adjuvant rabies vaccine(MRC-5 cell)for human use in cynomolgus monkeys / 中国人兽共患病学报

ABSTRACT

To evaluate the immunogenicity of BCG-CpG-DNA-adjuvanted human rabies vaccine(MRC-5 cell)in cynomol-gus monkeys,we randomly divided monkeys into a control group,three-dose group,and four-dose group.The three-dose and four-dose groups were vaccinated with BCG-CpG-DNA-adjuvanted human rabies vaccine for human use at 0,7,and 21,or at 0,3,7,and 14 days,respectively.The control group was vaccinated with a commercially available domestic vaccine with a 2-1-1 protocol.Serum samples were collected from all monkeys before(0 day)and after immunization,on days 7,14,28,35,49,and 63.RFFIT and ELISPOT were used to detect anti-rabies virus neutralizing antibodies and cytokines(IFN-γ and IL-2).The anti-rabies virus neutralizing antibodies in all groups were negative before immunization.The three-dose and control groups showed an increasing trend from 7 to 28 days after primary immunization,and the highest level was reached on the 28th day;in contrast,the four-dose group showed a peak on the 14th day.On the 28th day,the neutralizing antibody levels in the control and three-dose groups were significantly higher than those in the four-dose group.On the 35th day after the initial immuniza-tion,the neutralizing antibodies in the three-dose group was significantly higher than those in the four-dose group.The levels of IL-2 and IFN-γ in peripheral blood lymphocytes in the three-dose and four-dose groups tended to increase from 7 to 14 days and peaked on the 14th day;the level of IFN-γ in the three-dose group was significantly higher than that in the control group on the 14th day.Otherwise,no significant differences in the levels of neutrali-zing antibodies and cytokines were observed among all groups at all other time points.Thus,BCG-CpG-DNA adjuvanted human rabies vaccine(MRC-5 cell)has excellent immunogenicity and application value for optimizing immunization procedures.