ABSTRACT
Vi polysaccharide typhoid vaccines cannot be used in children <2 years owing to poor immunogenic and T cell independent properties. Conjugate vaccine prepared by binding Vi to tetanus toxoids (Vi-TT) induces protective levels even in children <2 years. We evaluated efficacy and safety following vaccination with a Vi-TT vaccine in children 6 months to 12 years of age. Overall, 1765 subjects were recruited from two registered municipal urban slums of southern Kolkata. Most of the children of the slum dwellers attended the schools in the locality which was selected with permission from the school authority. Schools were randomly divided into vaccinated (Test group) and unvaccinated group (Control group). Children and their siblings of test group received 2-doses of PedaTyph™ vaccine at 6 weeks interval. Control group received vaccines as per national guidelines. Adverse events (AEs) were examined after 30 minutes, 1 month and clinical events were observed till 12 months post-vaccination. Incidence of culture positive typhoid fever in the control group was 1.27% vis-a-vis none in vaccine group during 12 months. In subgroup evaluated for immunogenicity, an antibody titer value of 1.8 EU/ml (95% CI: 1.5 EU/ml, 2.2 EU/ml), 32 EU/ml (95% CI: 27.0 EU/ml, 39.0 EU/ml) and 14 EU/ml (95% CI: 12.0 EU/ml, 17.0 EU/ml) at baseline, 6 weeks and 12 months, respectively was observed. Sero-conversion among the sub-group was 100% after 6 weeks of post-vaccination and 83% after 12 months considering 4-fold rise from baseline. The efficacy of vaccine was 100 % (95% CI: 97.6%, 100%) in the first year of follow-up with minimal AEs post vaccination. Vi conjugate typhoid vaccine conferred 100% protection against typhoid fever in 1765 children 6 months to 12 years of age with high immunogenicity in a subgroup from the vaccine arm.
Subject(s)
Antibodies, Bacterial/blood , Immunogenicity, Vaccine , Polysaccharides, Bacterial/adverse effects , Polysaccharides, Bacterial/immunology , Salmonella typhi/immunology , Typhoid Fever/prevention & control , Typhoid-Paratyphoid Vaccines/adverse effects , Typhoid-Paratyphoid Vaccines/immunology , Child , Child, Preschool , Female , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , India , Male , Polysaccharides, Bacterial/administration & dosage , Seroconversion , Tetanus Toxoid/adverse effects , Tetanus Toxoid/immunology , Typhoid Fever/immunology , Typhoid-Paratyphoid Vaccines/administration & dosage , Vaccination , Vaccines, Conjugate/administration & dosage , Vaccines, Conjugate/adverse effects , Vaccines, Conjugate/immunologyABSTRACT
Varicella, an acute viral systemic infection that may cause lifelong latent infection with the potential for causing clinical reactivation, may be prevented by immunization. The present study was an open label, randomized, controlled, phase III, multicentre trial, conducted to evaluate and compare the safety, tolerability and immunogenicity of a freeze dried live attenuated Oka strain Varicella Vaccine (VR 795 Oka strain) with Varilrix (Oka-RIT strain) in children. A total of 268 healthy Indian children aged 12 months to 12 y with baseline VZV IgG antibody (<100 mIU/ mL) were enrolled, and 256 children completed the study. The extent of rise of VZV IgG antibody titer assessed as 3-fold and 4-fold rise from baseline was found to be significantly higher (89.1% and 85.2%) in the test group as compared to control group (73.4% and 61.7%). The post-vaccination GMT of the test group was significantly higher (112.5 mIU/mL) as compared with the control group (67.8 mIU/mL) (P < 0.001). The seroconversion rate considering the 5 gp ELISA units/ml equivalent to 10mIU/ml were similar in the control (96.5%) and the test (98.3%) groups. The adverse events were not different in the control and test groups (P > 0.05). The test live attenuated vaccine was found to be highly immunogenic, safe and comparable to Varilrix used in control arm.
Subject(s)
Antibodies, Viral/blood , Chickenpox Vaccine/adverse effects , Chickenpox Vaccine/immunology , Chickenpox Vaccine/administration & dosage , Child , Child, Preschool , Drug-Related Side Effects and Adverse Reactions/epidemiology , Drug-Related Side Effects and Adverse Reactions/pathology , Enzyme-Linked Immunosorbent Assay , Female , Healthy Volunteers , Humans , Immunoglobulin G/blood , India , Infant , Male , Vaccines, Attenuated/administration & dosage , Vaccines, Attenuated/adverse effects , Vaccines, Attenuated/immunologyABSTRACT
OBJECTIVE: To evaluate immunogenicity and tolerability of single dose live attenuated injectable hepatitis A vaccine in four metropolitan cities of India. METHODS: Live attenuated hepatitis A vaccine was administered to 505 children aged 18 to 60 months in four centers across India. Immunogenicity of the vaccine was assessed by estimation of anti-HAV antibody titer at 6 weeks and 6 months following administration of the vaccine. Safety evaluation of the vaccine was also done during the visits. RESULTS: At 6 weeks, 480 subjects (95%) came for the follow-up and 411 (81.4%) subjects reported at the end of 6 months. The geometric mean titer (GMT) of anti-HAV antibody of the subjects who did not have the seroprotective titer at the baseline were assessed at 6 weeks and 6 months which was 81.04 mIU/ml and 150.66 mIU/ml respectively. At 6 weeks, 95.1 % seroconverted and at the end of 6 months, 97.9 % had seroconverted. Both solicited and unsolicited vaccine-induced local and systemic adverse events were insignificant at all the centers, except swelling and induration in a few. CONCLUSION: Live attenuated injectable hepatitis A vaccine was immunogenic and tolerable with minimal reactogenecity, in this study of single dose schedule. Safety profile was also satisfactory in the study population.
