Role of vaccine manufacturers in developing countries towards global healthcare by providing quality vaccines at affordable prices

Vaccines represent one of the greatest achievements of science and medicine in the fight against infectious diseases. Vaccination is one of the most cost-effective public health tools to prevent infectious diseases. Significant progress has been made in expanding the coverage of vaccines globally, resulting in the prevention of more than two million deaths annually. In 2010, nearly 200 countries endorsed a shared vision to extend the benefits of vaccines to every person by 2020, known as the Decade of Vaccine Initiative (DoV). Vaccine manufacturers in developing countries, as represented by the Developing Countries Vaccine Manufacturers Network (DCVMN), make a significant contribution to DoV by supplying quality vaccines at affordable prices to the people who need them most. About 70% of the global Expanded Program on Immunization (EPI) vaccine supplies are met by DCVMN. Besides EPI vaccine supplies, DCVMN is also targeting vaccines against rotavirus, Japanese encephalitis, pneumonia, human papillomavirus, meningitis and neglected tropical diseases. This article reviews the roles and contributions of DCVMN in making the vaccines accessible and affordable to all.

PHARMACOLOGICAL ACTIVITIES OF POLYHERBAL FORMULATION: SANJIVANI VATI

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Immune response modulation to DPT vaccine by aqueous extract of Withania somnifera in experimental system

Immunopotentiation on oral feeding of standardized aqueous extract of Withania somnifera (Linn. Dunal, Family Solanaceae) was evaluated in laboratory animals immunized with DPT (Diphtheria, Pertussis, Tetanus) vaccine. The immunostimulation was evaluated using serological and hematological parameters. Treatment of immunized animals with test material (100 mg/kg/day) for 15 days resulted in significant increase of antibody titers to B. pertussis (P=0.000007). Immunized animals (treated and untreated) were challenged with B. pertussis 18,323 strain and the animals were observed for 14 days. Results indicate that the treated animals did show significant increase in antibody titers as compared to untreated animals after challenge (P=0.000003). Immunoprotection against intracerebral challenge of live B. pertussis cells was evaluated based on degree of sickness, paralysis and subsequent death. Reduced mortality accompanied with overall improved health status was observed in treated animals after intracerebral challenge of B. pertussis indicating development of protective immune response. Present study indicates application of the test material as potential immunopotentiating agent possible applications in immunochemical industry. The test material also offers direct therapeutic benefits resulting in reduced morbidity and mortality of experimental animals.

Composition of acellular pertussis and combination vaccines: a general review

Since the development and introduction of the acellular pertussis vaccine in Japan in the early eighties, we have come a long way in using this component in combination with other vaccines. However, the basic problem in development of an effective and safe pertussis vaccine is that the antigens to induce complete protection against clinical pertussis and the precise mechanism by which pertussis vaccine confers immunity is yet unknown. Hence, the composition of future acellular pertussis vaccine remains an open issue. Recently, acellular pertussis vaccine has been licensed for the booster doses in the U.S.A. and for primary immunization of infants in Italy and Germany. A multicentric trial has been carried out to compare the serological response and adverse reactions of 13 acellular pertussis vaccines. These vaccines contained one or more of the four components, i.e. FHA, PT, 69 kDa OMP and fimbriae. All vaccines were associated with substantially fewer and less adverse reactions and were more immunogenic with respect to antibodies against the added antigens. DTP vaccines in the near future will have combinations of other components and the key antigen for combination will be acellular pertussis component which is going to replace whole cell pertussis component in DTP vaccines. In view of this, manufacturers like ourselves from the developing countries are still groping in the dark, uncertain whether we should have a single component acellular pertussis vaccine or multicomponent one. This will have a major impact on the cost of production, the final cost of the combination vaccines and the regulatory issues that we will have to tackle in view of the recent thinking on harmonization in the pharmaceutical industry.

Evaluation of potency of inactivated cholera vaccine by mouse protection assay & antibody induction method

Twenty one batches of whole cell inactivated cholera vaccine manufactured at Central Research Institute, Kasauli were evaluated for potency by mouse protection assay (MPA) and antibody induction method. In the antibody induction method the sera of immunized mice were screened for the presence of antibodies against Vibrio cholerae by microagglutination (MA) test and IgG ELISA. The number of organisms estimated by MPA were correlated with agglutinating and neutralizing antibodies against individual serotypes by MA and ELISA respectively. Correlation coefficient(r) of 0.692 and 0.815 were observed for the titres evaluated by MA and ELISA when compared with standard MPA method for the serotype Ogawa. Similarly r values of 0.925 and 0.849 were observed for titres evaluated by MA and ELISA when compared with standard MPA method for the serotype Inaba. Antibody induction method can be as an alternative method for determining the potency of inactivated cholera vaccine.