Background: We provide the first post-approval safety analysis of COVISHIELD in health care workers (HCWs) in northern India. Methods: This continuing prospective observational study (February 2021 to May 2022) enrolled participants 18 years receiving COVISHIELD vaccination. Primary outcome was safety and reactogenicity. Categories (FDA toxicity grading) and outcomes of adverse events following immunization (AEFIs) were recorded, causality assessment performed, and risk factors analysed. Findings: We present the results of an interim analysis of 804 participants. AEFIs following first dose were reported in 321 (40%; systemic involvement in 248). Among 730 participants who completed a 7-day followup post second dose, AEFIs occurred in 115 (15.7%; systemic in 99). Majority of AEFIs were mild-moderate and resolved spontaneously. Serious AEFIs, leading to hospitalization was noticed in 1 (0.1%) participant with suspicion of immunization stress related response (ISRR). AEFIs of grade 3 severity (FDA) were recorded in 4 participants (0.5%). No deaths were recorded. Regression analysis showed increased risk of AEFIs in younger individuals, a two times higher odds in females, those with hypertension or with history of allergy; and three times higher odds in individuals with hypothyroidism. Interpretation: COVISHIELD carries an overall favourable safety profile with AEFI rates much less than reported for other adenoviral vaccines. Females, those with hypertension, individuals with history of allergy and hypothyroidism may need watchful vaccine administration. This being an interim analysis and based on healthcare workers who may not reflect the general population demographics, larger inclusive studies are warranted for confirming the findings.

: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has spread worldwide and caused widespread devastation. In the absence of definitive therapy, symptomatic management remains the standard of care. Repurposing of many existing drugs including several anti-viral drugs is being attempted to tackle the COVID-19 pandemic. However, most of them have failed to show significant benefit in clinical trials. An attractive approach may be to target host proteases involved in SARS-CoV-2 pathogenesis. The priming of the spike (S) protein of the virus by proteolytic cleavage by the trans-membrane serine protease-2 (TMPRSS2) is necessary for fusion of the virus to the host cell after it binds to its receptor angiotensin converting enzyme-2 (ACE2). There are other proteases with varying spatiotemporal locations that may be important for viral entry and subsequent replication inside the cells, and these include trypsin, furin and cathepsins. In this report, we discuss the tentative therapeutic role of inhibitors of TMPRSS2, cathepsin, trypsin, furin, plasmin, factor X and elastase in infection caused by SARS-CoV-2. Both available evidence as well as hypotheses are discussed, with emphasis on drugs which are approved for other indications such as bromhexine, ammonium chloride, nafamostat, camostat, tranexamic acid, epsilon amino-caproic acid, chloroquine, ulinastatin, aprotinin and anticoagulant drugs. Simultaneously, novel compounds being tested and problems with using these agents are also discussed.

The ChAdOx1 nCoV-19 vaccine (Oxford University-Astra Zeneca) has demonstrated nearly 70% efficacy against symptomatic COVID-19 in trials and some real-world studies.The vaccine was the first to be approved in India in early January 2021 and is manufactured by the Serum Institute of India. Favorable short-term safety data of the vaccine in India in a real-world setting has been recently demonstrated. Here, we report secondary objective (COVID-19 occurrence) measures of the same ongoing prospective observational study in prioritized recipients of the vaccine. The findings are based on participants who could complete at least 2 months of follow-up (n = 1500; female/male: 472/1028; mean age: 38.8 years). Laboratory confirmed SARS-CoV-2 infection was observed in 27/65 participants (41%) who received a single dose and 271/1435 (19%) who received both doses. Specifically, among doctors, 18/27 (66.7%) one dose recipients and 131/377 (34.7%) fully vaccinated developed SARS-CoV-2 infection. The majority of the cases were mild in all groups, and most were breakthrough infections. The occurrence of "severe" COVID-19 was 7.7 times lower (0.4%) in fully vaccinated participants compared to partially vaccinated (3.1%). Four deaths were observed in the study. One of the four deaths was due to sepsis, two due to unspecified cardiac events, and one due to unspecified post-COVID-19 complications. The results of this preliminary analysis necessitate vigorous research on the performance of vaccines against variants, optimal timing of vaccination, and also optimal timings of effectiveness studies to guide future vaccination policy.