Protecting Indian schoolchildren against rabies: pre-exposure vaccination with purified chick embryo cell vaccine (PCECV) or purified verocell rabies vaccine (PVRV)

Although rabies can be effectively prevented by means of preexposure or post-exposure prophylaxis, in India, an estimated 17,000 to 20,000 human rabies deaths occur annually. Tragically, 50% of these victims are children under the age of 15. In addition to immediate post-exposure prophylaxis measures, including active and passive immunization, pre-exposure vaccination using tissue culture vaccines is a safe and effective but highly underutilized method of preventing rabies in humans living or working in areas at risk. This study assessed the safety and immunogenicity of Purified Chick Embryo Cell Vaccine (PCECV) and Purified Verocell Rabies Vaccine (PVRV), administered as a three-dose intramuscular pre-exposure regimen on days 0, 7 and 28 in 175 healthy schoolchildren. PCECV was administered after reconstitution using either 1.0 mL or 0.5 mL (half the diluent volume) and PVRV was given after reconstitution with 0.5 mL. Vaccine safety was assessed observer-blind, including pain assessment with a validated visual analogue scale for children. Rabies virus neutralizing antibody (RVNA) concentrations were measured on day 49 by RFFIT. All children developed adequate RVNA concentrations above 0.5 IU/mL. Solicited local and systemic reactions were within the range expected, pain after vaccination was reported in 2 to 12% of study subjects, fever was reported in 2 to 5%. There was no statistical difference by vaccination group or vaccination day. No unexpected or serious adverse event was reported during the study. In conclusion, PCECV and PVRV are safe and immunogenic when administered intramuscularly for pre-exposure prophylaxis of rabies in children. A 1.0 mL dilution volume for PCECV was as well tolerated as PVRV or PCECV reconstituted in half the volume.     

Safety and immunogenicity of a new chromatographically purified rabies vaccine in comparison to the human diploid cell vaccine

BACKGROUND: Although human diploid cell vaccine (HDCV) has been available for over two decades and has a proven record of efficacy, it is very expensive to produce and can only be made in small quantities. METHODS: In this trial, we compared the safety and immunogenicity of a new, chromatographically purified rabies vaccine (CPRV) with those of HDCV. One hundred and thirty-five healthy veterinary students were randomized in a 2:1 ratio between CPRV and HDCV respectively. Each student subsequently received an intramuscular injection of 0.5 mL of CPRV or 1mL of HDCV on days 0, 7, and 28, according to the standard preexposure regimen. Local safety data were collected for 7 days following each dose and systemic safety data for 42 days following the first dose. Vaccine administration and safety evaluation were performed by different site personnel. Sera for immunogenicity analysis were collected on days 0 (prevaccination), 28 and 42. RESULTS: All subjects achieved an antirabies antibody titer greater than or equal to the World Health Organization (WHO) accepted threshold level of seroconversion of 0.5 IU/mL after only two of three doses of vaccine in both groups. The geometric mean titers (IU/mL) in the CPRV and HDCV groups respectively were 6.54 (range 0.50 to 64.80) and 10.22 (range 0.70 to 51.40) on day 28, and 40.51 (range 5.40 to 278.00) and 37.71 (range 5.40 to 278.00) on day 42. The percentage of subjects experiencing local reactions within 3 days after any dose ranged from 65.2% to 80.9% in the CPRV group and from 77.3% to 84.4% in the HDCV group. The local reaction reported by the greatest percentage of subjects after each dose was pain/tenderness at the injection site, and most reactions were mild. Most of the reported local reactions resolved within 0 to 3 days postvaccination. Systemic reactions decreased from 76.4% after dose 1 to 36.0% after dose 3 in the CPRV group, and similarly from 55.6% to 31.8% in the HDCV group. For all postdose periods, the systemic reaction reported by the highest percentage of subjects was myalgia. No subjects experienced an immediate local or systemic reaction. CONCLUSIONS: In healthy adults, vaccination with CPRV using a preexposure schedule resulted in a safety and immunogenicity profile similar to that of HDCV.     

双价肾综合征出血热纯化疫苗(Vero细胞)在儿童和老年人中的免疫原性观察

目的    评价双价肾综合征出血热纯化疫苗(Vero细胞)在6～15岁儿童和>60岁老年人中的免疫原性。方法   对知情同意的500名6～15岁(儿童组)、16～60岁(成年人组)和>60岁(老年人组)的健康人群按2:1:2的人数比例非随机接种双价肾综合征出血热纯化疫苗(Vero细胞),其中以成年人组作为对照。用ELlSA和空斑减少中和试验测定儿童和老年人接种疫苗后的抗体阳转率和几何平均滴度(GMT)。结果 经ELISA测定,试验组(儿童和老年人)免疫后的抗体阳转率与成年人对照组的差异无统计学意义;老年人组与成年人组的抗体GMT差异无统计学意义,儿童组的GMT水平低于成年人组,差异有统计学意义,但GMT达到有效保护水平。经空斑减少中和试验测定,试验组的抗体阳转率和GMT与对照组的差异均无统计学意义。结论   疫苗对≥6岁的所有健康人群接种(禁忌证除外)均具有良好的免疫效果。     

An immunogenicity, safety and post-marketing surveillance of a novel adsorbed human diploid cell rabies vaccine (Rabivax) in Indian subjects

In 1999, Serum Institute of India indigenously developed an adsorbed human diploid cell rabies vaccine (Rabivax). During 2000-04, this new vaccine was subjected to a series of immunogenecity and safety studies. Initially, an experimental batch of Rabivax (adsorbed) was assessed on ten healthy adult volunteers and its response was comparable with that of Merieux inactivated rabies vaccine (MIRV, lyophilized) which was used as a control. Subsequently, Rabivax (adsorbed) was assessed on forty-five suspect rabid dog bite cases with MIRV as control. The vaccine was found to be equally safe and immunogenic as MIRV and showed better rabies virus neutralizing antibody (RVNA) response on day 90 than MIRV. A post-licensing study conducted on 150 cases of suspect rabid animal bites showed it to be safe and immunogenic. To assess its long-term sero-efficacy some of these subjects tested after one year of follow up showed that 84% of them had adequate RVNA titers. In addition, a routine post-marketing surveillance done on 1608 animal bite cases demonstrated that Rabivax (adsorbed) was safe and efficacious. The adverse events to Rabivax (adsorbed) included pain at injection site (3.4%), swelling with induration (2.8%), fever and headache (1.4%). No serious adverse event was reported from the studies. In conclusion, Rabivax (adsorbed) is an immunogenic, safe and efficacious vaccine for rabies prophylaxis in humans.     

Phase II feasibility study of high dose epirubicin plus etoposide and cisplatin (HDEEC) regimen in small cell lung cancer

Summary Seventeen patients with small cell lung cancer entered a phase II trial testing the feasibility of adding high dose epirubicin (100–120 mg/m², day 1) in combination with etoposide (60–80 mg/m², days 1–5) and cisplatin (70 mg/m², day 1) courses repeated every three weeks. Complete responders received thoracic (40 Gy) and prophylactic cranial (30 Gy) irradiation. Sixteen patients were evaluable for response and toxicity. Myelosuppression was the dose-limiting side effect. Neutropenic fever was observed in eight patients (53%) and stomatitis in six (40%). No patient had a > 14% decline in the cardiac ejection fraction. Strict adherence to the dose-schedule designed was impossible as doses were trimmed and delayed in 30% of instances.The overall objective response rate was 81% (95% confidence limits, 62% to 100%), in limited disease there were complete remissions in 57%. With a 16 months median follow-up, overall median survival was 13 months. This study was unable to prove the feasibility of epirubicin escalation when added to etoposidecisplatin combination, hampering the dose-intensification Norton-Simon model test.     

Discrimination of the Thai rejuvenating herbs Pueraria candollei (White Kwao Khruea), Butea superba (Red Kwao Khruea), and Mucuna collettii (Black Kwao Khruea) using PCR-RFLP

The tuberous roots of Pueraria candollei (White Kwao Khruea), Butea superba (Red Kwao Khruea) and Mucuna collettii (Black Kwao Khruea), which belong to the family Leguminosae, are used as rejuvenating herbs in traditional Thai medicine. Although all of these species have an indication for rejuvenation, each differs in its medicinal properties. Two varieties of P. candollei, var. mirifica and var. candollei, affect females, whereas B. superba and M. collettii exhibit effects on males. However, the identification of these roots according to the name “Kwao Khruea” is confusing due to the similarity in their features. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) was utilised to identify plant origin. The partial matK gene was amplified and subjected to restriction enzyme digestion with DdeI and TaqI. The restriction fragments generated differed in number and size. To test the reliability of the method, an admixture of the different Kwao Khruea species containing equal amounts of DNA was tested. The results showed combined restriction patterns, and each species could be detected in the background of the others. The method was also used to authenticate eight different crude drugs sold as various types of Kwao Khruea in Thai markets. The results showed that the misidentification of commercial drugs remains a problem in crude drug markets. The PCR-RFLP analysis developed here provides a simple and accurate discrimination of these rejuvenating “Kwao Khruea” species.     

Safety and immunogenicity of a pentavalent combination vaccine (diphtheria, tetanus, acellular pertussis, polio, and haemophilus influenzae type B conjugate) when administered as a fourth dose at 15 to 18 months of age

A DTaP-IPV//PRP-T combination vaccine (Pentacel) has been universally used in Canada to provide immunization against diphtheria, tetanus, pertussis, polio, and Haemophilus influenzae type b with single injections at 2, 4, 6 and 18 months of age. This randomized, multicenter study was conducted to evaluate administration of a fourth dose of DTaP-IPV//PRP-T at 15 to 18 months of age, similar to the US immunization schedule. Participants who had received three doses of DTaP-IPV//PRP-T by 8 months of age were enrolled at 12 months and randomized to receive a fourth dose at 15, 16, 17 or 18 months. Antibody levels for each vaccine antigen were measured prior to and four weeks following booster vaccination. Overall, 1782 subjects were immunized and monitored for adverse events, and 735 were evaluated for immune responses. Preimmunization antibody levels differed minimally by age, for all antigens. The immune responses elicited by DTaP-IPV//PRP-T were comparable between participants vaccinated at 15 or 16 months and those vaccinated at 17 or 18 months, as demonstrated by specific antibody geometric mean titers, seroprotection/seroresponse rates, and reverse cumulative distribution curves. The fourth dose was well tolerated in all age groups. Toddlers at 15, 16, 17 or 18 months of age are equally suitable recipients for booster immunization with the DTaP-IPV//PRP-T vaccine.