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Background Acute encephalitis syndrome (AES) is a major public health concern in India, and the Japanese Encephalitis (JE) virus is the most common cause of viral encephalitis in Asia affecting children under the age of 15 years. In India, despite the introduction of the JE vaccine (SA-14-14-2) in the immunization programme, JE continues to account for 15–20% of AES cases to date. This study evaluates the immunogenicity of live attenuated SA-14-14-2 JE vaccine in terms of persistence of the humoral response after two doses. Methods A cross-sectional study was conducted among 266 children belonging to one of the JE endemic regions of Uttar Pradesh, India. Blood samples were taken from children (2–10 years) and grouped according to the duration (in years) after two doses of the vaccine (5 groups with a class interval of 2 years). Informed written consent was obtained from the parents/guardians. All the samples collected were tested for the presence of anti-JEV-specific IgG antibodies by enzyme-linked immunosorbent assay (ELISA) and further confirmed by micro neutralization test (MNT) and immunofluorescence assays. Results Of the 266 samples tested by ELISA for anti-JEV-specific IgG antibodies, 260 (97.74%) were negative and 6 (2.26%) were equivocal. The geometric mean immune status ratio across the five groups, 0–2 years (n  = 59), 2–4 years (n  = 73), 4–6 years (n  = 65), 6–8 years (n  = 48) and 8–10 years (n  = 21) post-two doses of SA-14-14-2 JE vaccine was 1.143, 1.059, 1.138, 1.075 and 1.130, respectively, and the geometric mean titre obtained from MNT across the five groups was 10.77, 8.400, 8.453, 9.517 and 9.674, respectively. Conclusion The study showed a decreasing trend of anti-JEV specific IgG antibody titres across the five groups based on the duration following two doses of SA-14-14-2 vaccine. The results emphasize the significance of booster doses of vaccine for children living in endemic areas. [ABSTRACT FROM AUTHOR]

Neutralization of Beta and Delta variant with sera of COVID-19 recovered cases and vaccinees of inactivated COVID-19 vaccine BBV152/Covaxin. Inactivated COVID-19 vaccine BBV152/COVAXIN effectively neutralizes recently emerged B.1.1.7 variant of SARS-CoV-2. Keywords: Sputnik vaccine; antibody response; SARS-CoV-2; emerging variants; neutralization EN Sputnik vaccine antibody response SARS-CoV-2 emerging variants neutralization 1 4 4 06/08/22 20220401 NES 220401 SARS CoV-2 pandemic challenged the world with emerging multiple variants having high transmissibility and increased infectivity. [Extracted from the article]

The GMT ratio of B.1 to Delta was 4.2, indicating a significant reduction in neutralization titers for Delta as compared with B.1 (Figure 1B). Keywords: first wave; second wave; neutralizing antibody; SARS CoV-2; variants of concerns; Delta variant; India EN first wave second wave neutralizing antibody SARS CoV-2 variants of concerns Delta variant India 1 3 3 06/08/22 20220401 NES 220401 The emergence of multiple variants of concerns like Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2) and other variants, such as Epsilon (B.1.427/B.1.1429), Zeta (P.2), Eta (B.1.525), Theta (P3), Iota (B.1.526) and Kappa (B.1.617.1) has contributed to the worldwide development of multiple waves of the formidable COVID-19 pandemic.[1] Mid-September 2020 was associated with a maximal spike in the daily cases in India, with its lowest case load in January 2021 during the first wave with the G Clade (with D614G mutation-B.1) being causal. [Extracted from the article]

Background & objectives: A new indigenously developed technology, coronavirus disease (COVID) Kavach, an IgG immunoglobulin-based enzyme-linked immunosorbent assay (ELISA) kit, was developed in 2020 by the Indian Council of Medical Research-National Institute of Virology (ICMR-NIV), Pune, India. The primary objective of this study was to determine the total cost of development of COVID Kavach IgG ELISA and estimate the unit cost (UC) as well. Methods: The total development cost (TDC) of COVID Kavach and its UC during the early phase of pandemic mitigation were estimated through a micro-costing approach from provider's perspective. An activity-based bottom-up costing approach was used to facilitate data collection from all resources, and analysis was performed using Microsoft Excel version 2016. The micro-costing data were utilized to interpret the breakdown of cost across all inputs and different levels of activity. Results: The TDC of COVID Kavach was estimated to be 2,884,032 (US$ 38,265). The UC of providing test results for exposure to severe acute respiratory syndrome corona virus-2 (SARS-CoV-2) was estimated to be 300 (US$ 4) during July 2020. The capital and recurrent cost were incurred around 5-10 per cent and 90-95 per cent, respectively, in both the development and UC of COVID Kavach. The major portion of funds (70-80%) was utilized for procurement of laboratory consumables, followed by human resources (8-12%) in the development as well as for UC of COVID Kavach. Interpretation & conclusions: The estimates from this study can be useful for conducting economic evaluations, which will help in deciding upon the subsidy in government health facilities. The data may be useful to set up laboratory facilities analogous to the National Reference Laboratory located at the ICMR-NIV, Pune and for allotting sufficient budget to develop such assays in government-funded laboratories. [ABSTRACT FROM AUTHOR]

Background & objectives: Since the beginning of the year 2020, the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) impacted humankind adversely in almost all spheres of life. The virus belongs to the genus Betacoronavirus of the family Coronaviridae. SARS-CoV-2 causes the disease known as coronavirus disease 2019 (COVID-19) with mild-to-severe respiratory illness. The currently available diagnostic tools for the diagnosis of COVID-19 are mainly based on molecular assays. Real-time reverse transcription-polymerase chain reaction is the only diagnostic method currently recommended by the World Health Organization for COVID-19. With the rapid spread of SARS-CoV-2, it is necessary to utilize other tests, which would determine the burden of the disease as well as the spread of the outbreak. Considering the need for the development of such a screening test, an attempt was made to develop and evaluate an IgG-based ELISA for COVID-19. Methods: A total of 513 blood samples (131 positive, 382 negative for SARS-CoV-2) were collected and tested by microneutralization test (MNT). Antigen stock of SARS-CoV-2 was prepared by propagating the virus in Vero CCL-81 cells. An IgG capture ELISA was developed for serological detection of anti- SARS-CoV-2 IgG in serum samples. The end point cut-off values were determined by using receiver operating characteristic (ROC) curve. Inter-assay variability was determined. Results: The developed ELISA was found to be 92.37 per cent sensitive, 97.9 per cent specific, robust and reproducible. The positive and negative predictive values were 94.44 and 98.14 per cent, respectively. Interpretation & conclusions: This indigenously developed IgG ELISA was found to be sensitive and specific for the detection of anti-SARS-CoV-2 IgG in human serum samples. This assay may be used for determining seroprevalence of SARS-CoV-2 in a population exposed to the virus [ABSTRACT FROM AUTHOR]

Residual blood specimens collected at health facilities may be a source of samples for serosurveys of adults, a population often neglected in community-based serosurveys. Anonymized residual blood specimens were collected from individuals 15 - 49 years of age attending two sub-district hospitals in Palghar District, Maharashtra, from November 2018 to March 2019. Specimens also were collected from women 15 - 49 years of age enrolled in a cross-sectional, community-based serosurvey representative at the district level that was conducted 2 - 7 months after the residual specimen collection. Specimens were tested for IgG antibodies to measles and rubella viruses. Measles and rubella seroprevalence estimates using facility-based specimens were 99% and 92%, respectively, with men having significantly lower rubella seropositivity than women. Age-specific measles and rubella seroprevalence estimates were similar between the two specimen sources. Although measles seropositivity was slightly higher among adults attending the facilities, both facility and community measles seroprevalence estimates were 95% or higher. The similarity in measles and rubella seroprevalence estimates between the community-based and facility serosurveys highlights the potential value of residual specimens to approximate community seroprevalence.

Residual blood specimens provide a sample repository that could be analyzed to estimate and track changes in seroprevalence with fewer resources than household-based surveys. We conducted parallel facility and community-based cross-sectional serological surveys in two districts in India, Kanpur Nagar District, Uttar Pradesh, and Palghar District, Maharashtra, before and after a measles-rubella supplemental immunization activity (MR-SIA) from 2018 to 2019. Anonymized residual specimens from children 9 months to younger than 15 years of age were collected from public and private diagnostic laboratories and public hospitals and tested for IgG antibodies to measles and rubella viruses. Significant increases in seroprevalence were observed following the MR SIA using the facility-based specimens. Younger children whose specimens were tested at a public facility in Kanpur Nagar District had significantly lower rubella seroprevalence prior to the SIA compared to those attending a private hospital, but this difference was not observed following the SIA. Similar increases in rubella seroprevalence were observed in facility-based and community-based serosurveys following the MR SIA, but trends in measles seroprevalence were inconsistent between the two specimen sources. Despite challenges with representativeness and limited metadata, residual specimens can be useful in estimating seroprevalence and assessing trends through facility-based sentinel surveillance.

Introduction: Dengue, chikungunya and Japanese encephalitis are the most common arthropod-borne viral diseases in India. Due to overlapping clinical symptoms, accurate, high-quality and timely laboratory-based differential diagnosis is essential for control and containment of outbreaks. This is most commonly done by detection of IgM antibodies in serum using enzyme-linked immunosorbent assays. The Resource Centre for Virus Research and Diagnostic Laboratories (VRDLs) in Pune, India organized an external quality assurance (EQA) study to check the accuracy of serological diagnostics in the VRDL network., Methods: Three panels, one each for anti-dengue virus, anti-chikungunya virus and anti-Japanese encephalitis virus IgM antibodies, comprising six human serum samples (two positive and four negative) were distributed to test the sensitivity, specificity and reproducibility of serological testing in 124 VRDLs across India in 2018-19 and 2019-20., Results: Among the 124 VRDLs, the average concordance for both 2018-19 and 2019-20 was 98%. In 2018-19, 78.33%, 13.33% and 6.66% of VRDLs reported 100% concordance, 91-99% concordance and 81-90% concordance with the reference results, respectively, and 1.66% of VRDLs had concordance <80%. In 2019-20, 79.68%, 14.06% and 4.68% of VRDLs reported 100% concordance, 91-99% concordance and 81-90% concordance with the reference results, respectively, and 1.56% of VRDLs had concordance <80%., Conclusion: The EQA programme was beneficial for assessing and understanding the performance of the VRDLs. The study data indicate good proficiency in serological diagnosis of dengue, chikungunya and Japanese encephalitis in the VRDL network laboratories. Further expansion of the EQA programme to cover other viruses of public health importance will increase confidence among the VRDL network, and generate evidence of high-quality testing., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Authors.)

Background & Objectives: The global pandemic caused by SARS-CoV-2 virus has challenged public health system worldwide due to the unavailability of approved preventive and therapeutic options. Identification of neutralizing antibodies (NAb) and understanding their role is important. However, the data on kinetics of NAb response among COVID-19 patients are unclear. To understand the NAb response in COVID-19 patients, we compared the findings of microneutralization test (MNT) and plaque reduction neutralization test (PRNT) for the SARS-CoV-2. Further, the kinetics of NAb response among COVID-19 patients was assessed., Methods: A total of 343 blood samples (89 positive, 58 negative for SARS-CoV-2 and 17 cross-reactive and 179 serum from healthy individuals) were collected and tested by MNT and PRNT. SARS-CoV-2 virus was prepared by propagating the virus in Vero CCL-81 cells. The intra-class correlation was calculated to assess the correlation between MNT and PRNT. The neutralizing endpoint as the reduction in the number of plaque count by 90 per cent (PRNT 90 ) was also calculated., Results: The analysis of MNT and PRNT quantitative results indicated that the intra-class correlation was 0.520. Of the 89 confirmed COVID-19 patients, 64 (71.9%) showed NAb response., Interpretation & Conclusions: The results of MNT and PRNT were specific with no cross-reactivity. In the early stages of infection, the NAb response was observed with variable antibody kinetics. The neutralization assays can be used for titration of NAb in recovered/vaccinated or infected COVID-19 patients., Competing Interests: None