The immunogenicity and safety of vaccination with purified Vero cell rabies vaccine (PVRV) in China under a 2-1-1 regimen

Abstract

2 Because rabies is fatal in nearly 100% of cases, post-exposure prophylaxis (PEP) is among the most important measures for its prevention and control. For people exposed to rabies virus carrying animals, PEP consists of wound cleansing, rabies vaccination and passive immunization with rabies immune globulin, if necessary.3 A reported 12-15 million people in China receive PEP each year, which results in direct medical expenses around $280 million to $310 million. 4 The intramuscular PEP recommended by the World Health Organization (WHO) includes Essen 5-dose regimen and the Zagreb 4-dose regimen (2-1-1 regimen).5 The 2-1-1 regimen has been used in other countries for many years.6-8 However, in China, only the Essen regimen was formally approved since the Primary Hamster Kidney Cell Background: In china, rabies vaccine is only permitted to use under the essen 5-dose regimen for the rabies post-exposure prophylaxis (pep). However, purified chick embryo cell vaccine made in India (Rabipur) has been approved in use under 2-1-1 immune program in 2010. Our objective is to confirm the immunogenicity and safety of pVRV manufactured in china (speeDa) under 2-1-1 program, compared with Rabipur and with the essen 5-dose regimen. Results: all groups showed similar immunogenicity. The neutralizing antibody titers at D14 and D45 of all subjects showed more than 0.5 IU/ml. No moderate and severe adverse effects were observed, though mild adverse reactions may occur. Methods: a total of 112 subjects were divided into three groups: 50 subjects in test group a, 32 subjects in control group B and 30 subjects in control group c. "Zagreb" 2-1-1 program was chosen for group a and B using speeDa and Rabipur, "essen" 5-dose regimen was adopted for group c using speeDa, thus to observe the general and local reactions within 72 h post vaccination. serum samples were also collected at D0, D7, D14 and D45 to determine the rabies serum neutralizing antibody by rapid fluorescent focus inhibition test (RFFIT). conclusions: pVRV (speeDa), under 2-1-1 regimen, is equally safe and immunogenic as the pcecV (Rabipur) for postexposure prophylaxis vaccination.

Efficacy of Purified Vero Cell Rabies Vaccine (PVRV) under the Zagreb Regimen in Iran

“…In a study conducted in China using locally produced PVRV administered under the 2-1-1 regimen similar anti-body levels were reported [8]. Furthermore, Liu et al [8] did not observe a significant difference in antibody level between subjects undergoing vaccination under Essen protocol with those of Zagreb method. In line with the WHO recommendations, antibody ti-ters of ≥0.5 IU/ml was considered indicative of seroconversion and in this study, this value was almost 3 times higher; therefore seroconversion was 100% by day 21.…”

“…Zagreb regimen is a shortened version of Essen treatment, reducing the number of injections, visits and duration of the treatment, making it economically more acceptable. Clinical trials and epidemiological studies have demonstrated the efficacy of Zagreb protocol [8,10,12] All patients were negative for anti-rabies antibody prior to treatment (D0) but subsequently showed significant increase in anti-rabies antibody on day 21 (Table 1). In a study conducted in China using locally produced PVRV administered under the 2-1-1 regimen similar anti-body levels were reported [8].…”

“…Clinical trials and epidemiological studies have demonstrated the efficacy of Zagreb protocol [8,10,12] All patients were negative for anti-rabies antibody prior to treatment (D0) but subsequently showed significant increase in anti-rabies antibody on day 21 (Table 1). In a study conducted in China using locally produced PVRV administered under the 2-1-1 regimen similar anti-body levels were reported [8]. Furthermore, Liu et al [8] did not observe a significant difference in antibody level between subjects undergoing vaccination under Essen protocol with those of Zagreb method.…”

“…Sera were diluted at 1:3 in the 96-wells micro plates and mixed with a constant dose of challenge virus sufficient to cause infection in 80% of the cells and the sera-virus mixture was incubated at 37°C for 1 h. After incubation, susceptible cells were added to the serum-virus mixtures, and after a further 24 h of incubation, the cell monolayer was acetone fixed and stained with anti-nucleocapsid conjugate (Bio-Rad, France) according to the manufacturer`s instructions and the fluorescent foci counted. Calculations were done by the Reed and Muench method [8]. Anti-rabies neutralizing antibody titers were also determined by ELISA (Bio-Rad, USA) according to the manufacturer`s instruction.…”

“…Rabies neutralizing antibody titer was measured using the rapid fluorescent focus inhibition test (RFFIT) as described by WHO [8,9] using international reference sera as control. Briefly, The BSR cells (a clone of baby hamster ovary cells) were grown and used in the test as described previously [9].…”