Rabies Vaccine Present Scenario and Urgent Need of Improvement Gaikwad A S1, Kulkarni D G2, Kadam N2 1
ICMR-NIOH-Regional Occupational Health Centre (Southern), Bangalore , 2 Isera Biological Pvt. Ltd., Maharashtra
ABSTRACT
BACKGROUND
Background- Rabies is highly fatal encephalitis, caused by a lyssavirus, and vaccinepreventable but disregarded. Rationale- Though rabies is vaccine preventable, does available vaccines (inactive rabies virus and anti-rabies immunoglobulin) efficient in terms of their protective property and quality as well as produces any side effects? Or need any improvements. Strategy- A total of six inactivated rabies virus vaccine quantified for albumin (stabilizer) content. The purity of inactivated rabies virus vaccines and anti-rabies immunoglobulin (ARS) were evaluated by SDS-PAGE analysis. The antigenic identity of rabies vaccine and neutralizing efficiency of ARS were analyzed by immunodiffusion assay. Finally, anti-rabies immunoglobulin was tested for their reactivity against human albumin with immunodiffusion assay. Results- Among studied 6 rabies vaccines 3 showed the highest albumin content range from 1.7 - 4.9 g% as compared to the other vaccines. Purity analysis of the rabies vaccines revealed broad band (69-79KD) in albumin highest vaccines while the narrow band (67.6KD) in albumin lowest vaccine. One of the vaccines showed more protein bands. While in 2 of 5 antirabies serums observed impurities. Antigenic identity analysis revealed that R1 rabies vaccine showed partial identity with others except with R2 whereas; V2 vaccine did not show identity with others at all. Anti-rabies immunoglobulin showed varying degrees of vaccine neutralization. Interestingly of 5 studied ARS, 2 showed activity against human albumin. Conclusion- The study findings suggest assessing effectiveness and quality of vaccines as well as the detection of emerging variants of rabies, if any, intermittently and improvement of available vaccines accordingly.
Rabies is highly fatal lethal encephalitis, caused by a lyssavirus, and vaccine-preventable but disregarded. Rabies virus is highly mutant which results in a diverse pool of rabies virus. India contributes about 36% of rabies deaths each year.
FATALITY RATE OF DISEASES
OBJECTIVES 1) To check the albumin content of vaccine 2) To check the purity of vaccine and anti-rabies immunoglobulin (ARS) 3) To check the antigenic identity of vaccine and neutralizing efficiency of ARS 4) To check the activity of ARS against human albumin
RESULTS 1. Among studied 6 rabies vaccines 3 showed highest albumin content range from 1.7 -4.9 g% as compared to the other vaccines. RV
Ppt line
L1-Lower range protein molecular weight marker,L2- V1, L3-V2, L4-V3, L5-V4, L6-V5, L7-V6, L8-Higher range protein molecular weight marker.
Fig.1 SDS-PAGE of Inactivated rabies vaccines
L1-Lower range protein molecular weight marker,L2- ARS 3, L3-ARS 5, L4-ARS 4, L5-ARS 2, L6-ARS 1, L7-Higher range protein molecular weight marker
Fig. 2 SDS-PAGE of anti-rabies immunoglobulin (ARS)
Table-1 Inactivated Rabies Virus Neutralizing Activity of ARS
Note- ‘++’ Present, ‘-’ absent , ARS-Antirabies Serums, RV-Rabies vaccine
CONCLUSION The study findings suggest assessing the effectiveness and quality of vaccines as well as the detection of emerging variants of rabies, if any, intermittently and improvement of available vaccines accordingly.
SIGNIFICANCE AND SCOPE OF THE STUDY 1) Identification/Characterization of emerging variants of rabies, if any, intermittently. 2) Utilization of different variants of rabies viral strains for effective active immunization or production of anti-rabies immunoglobulin’s (passive immunization). 3) When inactivated rabies vaccine with human albumin as a preservative is used for hyperimmunization of equines, it will produce antibodies against human albumin and it may cause a reaction to the patient and hence it is advisable to remove such antibodies. 4) Use alternative preservative to human albumin 5) Rabies can be cured if bite cases of rabies susceptible animals are treated properly or if rabies susceptible animals are vaccinated regularly.
ARS
RV- Inactivated rabies vaccine; ARS- Anti-rabies immunoglobulin; Ppt line- Precipitation line
Fig. 3 Immunodiffusion assay for inactivated rabies virus antigenic similarity analysis
Table.2 Activity of ARS against Human Albumin
Note- ‘++’ Present, ‘-’ absent , ARS-Antirabies Serums
ACKNOWLEDGEMENT We sincerely thank to all our colleagues who helped us directly or indirectly during this study.
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