Measles and rubella seroprevalence in adults using residual blood samples from health facilities and household serosurveys in Palghar District, Maharashtra, India, 2018 - 2019.

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.

Harmonization of Zika serological assays and comparative evaluation of two commercial ZIKA IgG ELISA kits.

The interpretation for Zika virus serology results is challenging due to high antibody cross reactivity with other flaviviruses. This limits availability of reliable and accurate methods for serosurveillance studies to understand the disease burden. Therefore, we conducted study to harmonize anti-Zika IgG antibody detection assays with 1 WHO International Standard (16/352) and working standard (16/320) for anti-Zika virus antibody.

Neutralizing antibody responses to SARS-CoV-2 Omicron variants: Post six months following two-dose & three-dose vaccination of ChAdOx1 nCoV-19 or BBV152.

Background Objectives: The Omicron sub-lineages are known to have higher infectivity, immune escape and lower virulence. During December 2022 - January 2023 and March - April 2023, India witnessed increased SARS-CoV-2 infections, mostly due to newer Omicron sub-lineages. With this unprecedented rise in cases, we assessed the neutralization potential of individuals vaccinated with ChAdOx1 nCoV (Covishield) and BBV152 (Covaxin) against emerging Omicron sub-lineages.

Cost estimation of COVID Kavach test developed in 2020: A National Reference Laboratory initiative during early phase of Indian pandemic mitigation.

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.

Broadly Reactive SARS-CoV-2-Specific T-Cell Response and Participation of Memory B and T Cells in Patients with Omicron COVID-19 Infection.

January 2022 onward, India witnessed a sudden increase in Omicron COVID-19 infections, having a mild course that prompted us to identify the key host factors/immune molecules modulating disease course/outcomes. The current study evaluated the percentages of lymphocyte subsets by flowcytometry, SARS-CoV-2 specific T-cell immune response by ELISPOT, estimation of plasma cytokine/chemokine levels on a Bio-plex Multiplex Immunoassay System and anti-SARS-CoV-2 IgG levels by enzyme-linked immunosorbent assay in 19 mild Omicron infected patients, 45 mild SARS-CoV-2 (2020) patients and 36 uninfected controls from India. Natural killer cells, B and memory B cells were high in vaccinated and total Omicron-infected patients groups compared to the mild SARS-CoV-2 (2020) patient group, while CD8 T cells were high in total Omicron-infected patients group compared to the uninfected control group ( < 0.

Host immune responses in aged rhesus macaques against BBV152, an inactivated SARS-CoV-2 vaccine, and cross-neutralization with beta and delta variants.

The magnitude and duration of immune response to COVID-19 vaccination in older adults are known to be adversely affected due to immunosenescence and inflammaging. The threat of emerging variants warrants studies on immune response in older adults to primary vaccination and booster doses so as to understand the effectiveness of vaccines in countering the threat of emerging variants. Non-human primates (NHPs) are ideal translational models, as the immunological responses in NHPs are similar to those in humans, so it enables us to understand host immune responses to the vaccine.

External quality assurance of serological diagnosis of dengue, chikungunya and Japanese encephalitis virus infection.

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.

Needle-free injection system delivery of ZyCoV-D DNA vaccine demonstrated improved immunogenicity and protective efficacy in rhesus macaques against SARS-CoV-2.

The apprehension of needles related to injection site pain, risk of transmitting bloodborne pathogens, and effective mass immunization have led to the development of a needle-free injection system (NFIS). Here, we evaluated the efficacy of the NFIS and needle injection system (NIS) for the delivery and immunogenicity of DNA vaccine candidate ZyCoV-D in rhesus macaques against SARS-CoV-2 infection. Briefly, 20 rhesus macaques were divided into 5 groups (4 animals each), that is, I (1 mg dose by NIS), II (2 mg dose by NIS), III (1 mg dose by NFIS), IV (2 mg dose by NFIS) and V (phosphate-buffer saline [PBS]).

Evaluation of immunogenicity post two doses of inactivated SARS-CoV-2 vaccine, Covaxin after six months.

We have evaluated the immunogenicity of two dose of Covaxin given at a one-month interval to two adult populations, i.e. COVID-19 naïve-vaccinated individuals (n = 118) and COVID-19 recovered individuals (n = 128) with the vaccination.

Evaluating the effect of measles and rubella mass vaccination campaigns on seroprevalence in India: a before-and-after cross-sectional household serosurvey in four districts, 2018-2020.

Background: India did phased measles-rubella supplementary immunisation activities (MR-SIAs; ie, mass-immunisation campaigns) targeting children aged 9 months to less than 15 years. We estimated measles-rubella seroprevalence before and after the MR-SIAs to quantify the effect on population immunity and identify remaining immunity gaps.

Methods: Between March 9, 2018 and March 19, 2020 we did community-based, cross-sectional serosurveys in four districts in India before and after MR-SIAs.

Waning natural and vaccine-induced immunity leading to reinfection with SARS-CoV-2 Omicron variant.

We have investigated six COVID-19 recovered cases with two doses of Covishield vaccination followed by reinfection. The primary SARS-CoV-2 infection found to occur with B.1 and reinfection with Omicron BA.

Protective efficacy of COVAXIN® against Delta and Omicron variants in hamster model.

The immunity acquired after natural infection or vaccinations against SARS-CoV-2 tend to wane with time. Here, we compared the protective efficacy of COVAXIN® following two- and three-dose immunizations against the Delta variant and also studied the efficacy of COVAXIN® against Omicron variants in a Syrian hamster model. Despite the comparable neutralizing antibody response against the homologous vaccine strain in both the two-dose and three-dose immunized groups, considerable reduction in the lung disease severity was observed in the 3 dose immunized group after Delta variant challenge.

Utility of serum and salivary lactate dehydrogenase and uric acid levels as a diagnostic profile in oral squamous cell carcinoma patients.

Background: Lactate dehydrogenase (LDH), an intra-cellular enzyme present in all cells of the body, catalyses the final step of anaerobic glycolysis. This intra-cellular enzyme is released into the extra-cellular space after tissue disintegration, which is evident in oral squamous cell carcinoma (OSCC). However, investigations comparing Lactate dehydrogenase (LDH) levels in OSCC and healthy controls have shown conflicting findings in both serum and saliva samples.

Zika a Vector Borne Disease Detected in Newer States of India Amidst the COVID-19 Pandemic.

Background: During the second wave of the COVID-19 pandemic, outbreaks of Zika were reported from Kerala, Uttar Pradesh, and Maharashtra, India in 2021. The Dengue and Chikungunya negative samples were retrospectively screened to determine the presence of the Zika virus from different geographical regions of India.

Methods: During May to October 2021, the clinical samples of 1475 patients, across 13 states and a union territory of India were screened and re-tested for Dengue, Chikungunya and Zika by CDC Trioplex Real time RT-PCR.

First case of Zika virus infection during an outbreak of chikungunya in a rural region of Maharashtra state, India.

Background: In July 2021, an outbreak of chikungunya virus (CHIKV) was reported in a rural region of Maharashtra state, India.

Methods: Serum samples of symptomatic cases (n=33) were screened for dengue virus (DENV), CHIKV and Zika virus (ZIKV) by molecular and serological assays.

Results: The first case of ZIKV infection from Maharashtra was detected and confirmed by molecular and serological assays.

Pathogenicity of SARS-CoV-2 Omicron (R346K) variant in Syrian hamsters and its cross-neutralization with different variants of concern.

Background: SARS-CoV-2 Omicron variant is rampantly spreading across the globe. We assessed the pathogenicity and immune response generated by BA.1.

Immune responses against different variants of SARS-CoV-2 including Omicron following 6 months of administration of heterologous prime-boost COVID-19 vaccine.

Comparative analysis at one- and six-months post-vaccination showed modest reduction in S1-RBD IgG antibody and NAb titers against B.1, Alpha, Beta and Delta variants in heterologous and homologous vaccine recipients groups. However, significant reduction in NAb titers against Omicron in vaccinees’ sera post-six months underlines need for cautious prospective follow-up.