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BackgroundDelta variant transmission resulted in surge of SARS CoV-2 cases in New Delhi, India during the early half of year 2021. Health Care Workers (HCWs) received vaccines on priority for prevention of infection. Real life effectiveness of BBV152 vaccine against severe disease including hospitalization and death was not known. ObjectiveTo estimate effectiveness of BBV152 vaccine among HCWs against SARS CoV-2 infection, hospitalization or death DesignObservational study Settinga multi -speciality tertiary care public funded hospital in New Delhi, India. Participants12,237 HCWs InterventionsBBV152 vaccine (Covaxin, Bharat Biotech limited, Hyderabad, India); whole virion inactivated vaccine; two doses four weeks apart Measurementsvaccine effectiveness after receipt of two doses of BBV152 protecting against any SARS CoV-2 infection, symptomatic infections or hospitalizations or deaths, and hospitalizations or deaths. ResultsThe mean age of HCWs was 36({+/-}11) years, 66% were men and 16% had comorbidity. After adjusting for potential covariates viz age, sex, health worker type category, body mass index, and comorbidity, the vaccine effectiveness (95% Confidence Interval) in fully vaccinated HCWs and [≥]14 days elapsed after the receipt of second dose was 44% (37 to 51, p<0.001) against symptomatic infection, hospitalization or death due to SARS CoV-2, and 61% (37 to 76, p<0.001) against hospitalization or death, respectively. ConclusionsBBV152 vaccine with complete two doses offer a modest response to SARS CoV-2 infection in real life situations against a backdrop of high delta variant community transmission. Efforts in maximizing receipt of full vaccines should be invested for HCWs, who are at higher occupational risk for infection.
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SARS-CoV-2 infection in children frequently leads to only asymptomatic and mild infections. It has been suggested that frequent infections due to low-pathogenicity coronaviruses in children, imparts immunity against SARS-CoV-2 in this age group. From a prospective birth cohort study prior to the pandemic, we identified children (n=42) with proven low-pathogenicity coronavirus infections. Convalescent sera from these samples had antibodies against the respective seasonal CoVs as demonstrated by immunofluorescence assay. We tested these samples for neutralization of SARS-CoV-2 using virus microneutralization assay. Forty serum samples showed no significant neutralization of SARS-CoV-2, while 2 samples showed inconclusive results. These findings suggest that the antibodies generated in low-pathogenicity coronavirus infections offer no protection from SARS-CoV-2 infection in young children.
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BackgroundQuarantine of healthcare workers (HCWs) exposed to COVID -19 confirmed cases is a well-known strategy for limiting the transmission of infection. However, there is need of evidence-based guidelines for quarantine of HCWs in COVID -19. MethodsWe describe our experience of contact tracing and risk stratification of 3853 HCWs who were exposed to confirmed COVID-19 cases in a tertiary health care institution in India. We developed an algorithm, on the basis of risk stratification, to rationalize quarantine among HCWs. Risk stratification was based on the duration of exposure, distance from the patient, and appropriateness of personal protection equipment (PPE) usage. Only high-risk contacts were quarantined for 14 days. They underwent testing for COVID-19 after five days of exposure, while low-risk contacts continued their work with adherence to physical distancing, hand hygiene, and appropriate use of PPE. The low-risk contacts were encouraged to monitor for symptoms and report for COVID-19 screening if fever, cough, or shortness of breath occurred. We followed up all contacts for 14 days from the last exposure and observed for symptoms of COVID-19 and test positivity. Results and interpretationOut of total 3853 contacts, 560 (14.5%) were categorized as high-risk contacts, and 40 of them were detected positive for COVID-19, with a test positivity rate of 7.1% (95% CI = 5.2 - 9.6). Overall, 118 (3.1%) of all contacts tested positive. Our strategy prevented 3215 HCWs from being quarantined and saved 45,010 person-days of health workforce until June 8, 2020, in the institution. We conclude that exposure-based risk stratification and quarantine of HCWs is a viable strategy to prevent unnecessary quarantine, in a healthcare institution. SummaryO_ST_ABSWhat is already known about this subject?C_ST_ABSO_LIQuarantine of HCWs is a well-known strategy for community and HCWs to prevent the transmission of COVID-19. C_LIO_LIThough success stories of prompt contact tracing and quarantine to control COVID-19 are available from countries like South Korea, Singapore, and Hong Kong, there is a scarcity of evidence that could guide targeted quarantine of HCWs exposed to COVID -19 in India. C_LI What does this study add?O_LIOnly 14.5% HCWs exposed to COVID-19 cases were stratified "high risk" contacts, and the most common reason for high-risk contacts was non-formal workplace interactions such as having meals together. C_LIO_LIThe overall test positivity rate among the high-risk contacts was 7.1%, while it was higher in symptomatic high-risk contacts as compared to those who were asymptomatic (10.2% vs. 6.3%). C_LI How might this impact on clinical practice?O_LIContact tracing and risk stratification can be used to minimize unnecessary quarantine of COVID-19 exposed health care workers and prevent the depletion of healthcare workers amidst the pandemic to continue the healthcare services optimally. C_LI
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ImportanceInsights into the country-wise differences in COVID-19 burden can impact the policies being developed to control disease spread. ObjectivePresent study evaluated the possible socio-economic and health related factors (and their temporal consistency) determining the disease burden of COVID-19. DesignA retrospective analysis for identifying associations of COVID-19 burden. SettingData on COVID-19 statistics (number of cases, tests and deaths per million) was extracted from the website https://www.worldometers.info/coronavirus/ on 10th April and 12th May. Variables obtained to estimate the possible determinants for COVID-19 burden included economic-gross domestic product; socio-demographic-Sustainable Development Goals, SDGs indicators related to health systems, percentage Chinese diaspora; and COVID-19 trajectory-date of first case in each country, days between first reported case and 10th April, days between 100th and 1000th case, and government response stringency index (GRSI). Main outcomes and MeasuresCOVID-19 burden was modeled using economic and socio-demographic determinants. Consistency of inferences for two time points at three levels of increasing statistical rigor using (i) Spearman correlations, (ii) Bayesian probabilistic graphical model, and (iii) counterfactual impact was evaluated. ResultsCountries economy (reflected by GDP), mainly through the testing rates, was the major and temporally consistent determinant of COVID-19 burden in the model. Reproduction number of COVID-19 was lower where mortality due to water, sanitation, and hygiene (WaSH) was higher, thus strengthening the hygiene hypothesis. There was no association between vaccination status or tuberculosis incidence and COVID burden, refuting the claims over BCG vaccination as a possible factor against COVID-19 trajectory. Conclusion and RelevanceCountries economy, through testing power, was the major determinant of COVID-19 burden. There was weak evidence for hygiene hypothesis as a protective factor against COVID-19.
