Design of an observational multi-country cohort study to assess immunogenicity of multiple vaccine platforms (InVITE)

In response to the COVID-19 pandemic, COVID-19 vaccines have been developed, and the World Health Oraganization (WHO) has granted emergency use listing to multiple vaccines. Studies of vaccine immunogenicity data from implementing COVID-19 vaccines by national immunization programs in single studies spanning multiple countries and continents are limited but critically needed to answer public health questions on vaccines, such as comparing immune responses to different vaccines and among different populations.

Fixed dose combinations for tuberculosis: Lessons learned from clinical, formulation and regulatory perspective

Worldwide, tuberculosis (TB) remains one of the most important communicable diseases in terms of morbidity and mortality. Its control requires multi-drug therapy for at least six months, which could lead to patient non-compliance, failure of therapy and ultimately resulting in the emergence of drug resistance. Fixed dose combinations (FDCs) in TB therapy reduce the number of tablets to be consumed and thereby increase patient compliance with recommended treatment regimens. Thus, FDCs play a significant role in preventing the emergence of drug resistance and successful treatment. However, the quality of FDCs with respect to variable bioavailability and their registration requirements are major hurdles to their implementation in national TB control programs. It is anticipated that a large global market for FDCs will encourage large-scale production and increased competition, which in turn will result in FDCs at affordable prices. The Global Drug Facility (GDF), established by the World Health Organization (WHO), aims to ensure universal uninterrupted access to quality TB drugs for implementation of directly observed treatment short-course (DOTS) in resource-poor countries. In this program, four FDCs were accepted as the drugs of first choice because of their obvious advantages in controlling TB. This demands the necessity of addressing quality and registration requirements of FDCs systematically. In light of this current knowledge on anti-TB FDCs, their dosage, combinations, available clinical studies and the experiences with TB therapy has been discussed in this article, which should serve as lessons for selection of appropriate FDCs for other diseases such as malaria and AIDS.

Target lymphoid cells for the cytotoxic factor produced in the spleen of dengue virus-infected mice

In previous studies we have observed the production of a cytotoxic factor by the T-lymphocytes in the spleen of dengue type-2 virus- (DV) infected mice which killed normal mouse spleen cells in vitro. In the present study types of spleen cells affected in vitro by the cytotoxic factor (CF) have been investigated. It was observed that it kills of the macrophages, one-third of T-lymphocytes and a few of the granulocytes, normoblasts and megakaryocytes. It had no effect on B-lymphocytes. The proportion of killed cells could not be significantly enhanced by retreatment of cells by additional CF. The cytotoxic activity of CF is not affected by adsorption with susceptible or non-susceptible cells. CF also kills lymphoid cells of animals of other species, viz. albino rats, rabbits, guinea pigs but had no effect on those of rooster. It had no effect on various cell cultures.