Injections Of Rabies Vaccine Research Articles

Immunogenicity and safety of two-visit, intradermal pre-exposure rabies prophylaxis simultaneously administrated with chimeric live-attenuated Japanese encephalitis vaccine in children living in rabies and Japanese encephalitis endemic country

BackgroundReducing the number of doses required for pre-exposure prophylaxis (PrEP) would make it more feasible and cost-effective to implement in children at the highest risk of rabies exposure in Asia. We studied immune response of 2-site intradermal (ID) injection of rabies vaccine on days 0 and 28 for rabies PrEP simultaneously administrated with live-attenuated Japanese encephalitis chimeric virus vaccine (JE-CV) for children living in endemic area. Research design and methodsSeronegative children (n = 49) aged 12–16 months were randomized 2:1 into two groups: Group A subjects were vaccinated with 0.1-mL ID injection of purified Vero cell rabies vaccine (PVRV), each at two sites on day (D) 0 and D28; Group B subjects were vaccinated with conventional 0.5-mL intramuscular PVRV on D0, D7 and D28. Both groups received one dose of JE-CV subcutaneously on D0 and D365. Rabies virus neutralizing antibody (RVNA) titers were measured on D0, D42 and D365 after vaccination; Japanese Encephalitis (JE) neutralizing antibody titers were determined on D0, D42, D365 and D379. ResultsAll children had RVNA ≥ 0.5 IU/mL on D42 (geometric mean titers [GMTs] of RVNA 14.35 IU/mL [Group A] and 14.83 IU/mL [Group B], p > 0.05]). On D365, RVNA GMTs of subjects in group A and B were 1.50 IU/mL and 2.00 IU/mL (p > 0.05), respectively. All children had seroprotection following booster dose of JE-CV. There were no vaccine-related SAEs observed. ConclusionThe 2-site ID PrEP with PVRV on days 0 and 28 co-administrated with JE-CV are safe and immunogenic.

Wound-only injection of rabies immunoglobulin (RIG) saves lives and costs less than a dollar per patient by “pooling strategy”

Since 2008, we in Himachal Pradesh have used a “pooling strategy” to help patients save money by pooling vials of antirabies vaccine at a centralized hospital and sharing them using the intradermal technique. In 2014, there was an acute shortage of rabies immunoglobulins (RIG) and two patients died after four injections of rabies vaccine were administered without RIG, which was not commercially available. After an extensive literature review and technical and ethical committee clearances, in June 2014 we started to infiltrate equine RIG (eRIG) into wound/s only without the recommended systemic intramuscular (IM) injection. WHO recommended this technique in 2018. During the four-year period June 2014 to June 2018, 7506 of 10,830 patients exposed to suspected rabid animals were injected with eRIG in and around the wounds in a single clinic at DDU Hospital Shimla without any adverse outcomes. The average volume of eRIG used per patient was 0.75 mL and cost US$ 0.75. Of the 80% of patients who were followed up, all were healthy at the end of a year, including 26 patients bitten by laboratory-confirmed rabid dogs. The reaction rate after PEP administration also declined significantly. Since February 2018, Himachal has started following the new WHO recommendations on PEP regimens of three intradermal antirabies vaccines instead of four, thereby saving hundreds of vaccine vials that became useful during shortages of rabies vaccine in India. To date, more than 700 vaccine vials have been saved in a single clinic at DDU hospital during the past 6 months alone. Not giving PEP to patients who have consumed raw milk from a suspected rabid cow has also saved 62 vials. Currently, 90 “pooling centers” have been established for sharing of vaccine and eRIG vials in Himachal State, generating huge savings that have enabled the government to provide PEP free of charge to all. The new WHO guidelines are a positive step towards a rabies-free world by 2030.

BCG modulation of delayed type hypersensitivity, humoral response and acquired resistance after rabies vaccination

The immunopotentiating action of BCG was evaluated in rabies. The maximum enhancing effect on delayed type hypersensitivity (DTH) was obtained 14 days after rabies immunization when different BCG vaccination schedules were tested in mice. A stable form of specific sensitization to rabies antigen under the modulation of BCG pretreatment was obtained. High concentrations of rabies antigen were found to be inhibitory for the DTH reaction. Levels of protection were evaluated in rabies vaccination after BCG modulation. One single injection of rabies vaccine in BCG pretreated mice was as effective as two injections of rabies vaccine in normal mice. However, in the latter, increase of protection was correlated with the levels of neutralizing antibody. On the other hand, the BCG pretreated mice, protection was not associated with a significant increase in antibody. Pretreatment with BCG alone influenced the outcome of fixed rabies as well as street rabies by enhancing the natural resistance to rabies infection.