An array of tests have been developed over a period of time for screening and diagnosis of HIV infection which include tests for detection of antigen and antibody, viral nucleic acid and the virus itself. Amongst the available tests, serodiagnosis by ELISA is widely being used. It offers a relatively inexpensive procedure with ease of performance and ability to effectively screen a large number of specimens. Our current study is designed to compare the performance of two different HIV diagnostic kits having different coated antigens using HIV dilutional panel. Kit 'X' had synthetic peptides (3rd generation), and the Kit 'Y' had recombinant antigens (2nd generation) coated on the microtitre plates. 10 HIV-1 plasma panel members which were collected from various blood banks were used for comparison of their performance. The plasma samples were diluted in human plasma (base matrix) negative for anti HIV, anti HCV, HBsAg, VDRL and HTLV I/II. Serial dilutions in the range of 10 to10,000 fold for each sample were used for this study. These kits were compared in terms of antibody titre which is defined as the dilution at which the sample OD to cut off (S/Co) value is 1. It was seen that Kit 'X' is more sensitive as compared to Kit 'Y' for all the HIV panel members. This indicates that Kit 'X' had better analytical sensitivity performance as compared to Kit 'Y' since the S/Co ~ 1.0 of Kit 'X' is at a higher dilution (1:1000) than of Kit 'Y' (1:100). Thus this indicates that dilutional panel can help the manufacturers to design a diagnostic kit which is able to detect the infection at an early stage of disease. It was seen that the S/Co ~ 1.0 of kit X at a higher dilution

Objectives: Cold chain maintenance is essential to ensure vaccine quality till it reaches the end user. In tropical countries like India with hot and humid environment, the transport of vaccines with required cold chain is comparatively difficult. Also, the efficacy of live viral vaccines is dependent on proper attenuation of vaccine virus. The present study was carried out to analyse the quality of 41 batches of rubella vaccine stored at 2-8°C and their thermostability after exposure at 37°C for 7 days, as such no study is published from India. Accordingly, the trends for the potency and stability titres of these batches of rubella vaccine were analysed during the present study. Method: All the Rubella vaccines batches were tested in triplicates against reference vaccine as per the WHO formula. The number of wells showing cytopathic effect was counted and titres were calculated using Spearman-Karber formula. The geometric mean titre was calculated for the triplicate readings. The assay is considered valid only if confidence limits (P=0.95) of the logarithm of the virus concentration is greater than ±0.3. WHO criteria state that minimum virus concentration should be 10 3.0 CCID 50 per human dose for both exposed and non-exposed rubella vaccine. Also, after incubation the loss in titre should not be more than 10 1.0 . Result: The potency and thermostability titres of all the batches tested were found to be between 10 3.467 to 10 4.03 and 10 3.276 to 10 3.72 respectively and were well within prescribed specifications of WHO. Conclusion: Potency and thermostability of the rubella vaccine tested were found in the acceptable range indicating rubella vaccine used in India is quite potent and thermostable.

Rabies is a fatal but preventable disease. Various cell culture rabies vaccines (CCRV) are recommended by World Health Organization (WHO) for pre-exposure prophylaxis and post-exposure therapeutic application. In the present study, we have evaluated seventy batches of inactivated CCRV, for safety and potency by test for Virus Inactivation and National Institute of Health (NIH) potency test respectively in Swiss albino mice, produced by four Indian manufacturers, using different cell substrates, rabies virus strains and inactivation methods. For a single batch evaluation, 0.03ml of undiluted vaccine sample was injected intracerebrally into each of 10 mice weighting between 12-15gms in Virus Inactivation test. In NIH potency test, three fivefold dilutions each of reference and test vaccines were used for immunization of mice. A group of 16 mice were immunized with each dilution on day 0 and 7, followed by a challenge dose of 5-50 LD 50 (Median Lethal dose) of Rabies Challenge Virus Standard (CVS) on day 14. The mice were observed for 14 days after challenge dose for the symptoms of fixed rabies virus. The ED 50 (50 % effective dose) of reference and test vaccine were calculated by Reed and Muench formula and the relative potency is calculated through comparison with the reference vaccine. The relative potency of the all the four rabies vaccines were above the recommended potency of 2.5IU/single human dose. All the vaccines tested were found to be safe & potent irrespective of the strain of rabies virus, substrate and inactivation process used in production.