key: cord-0744028-wyvfdufm
authors: Kaur, Upinder; Bala, Sapna; Ojha, Bisweswar; Jaiswal, Sumit; Kansal, Sangeeta; Chakrabarti, Sankha S.
title: Occurrence of COVID‐19 in priority groups receiving ChAdOx1 nCoV‐19 coronavirus vaccine (recombinant): A preliminary analysis from north India
date: 2021-09-12
journal: J Med Virol
DOI: 10.1002/jmv.27320
sha: 1081801c72dab67c851c3150642d973c4095d1b2
doc_id: 744028
cord_uid: wyvfdufm

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.

policies, COVISHIELD, based on the ChAdOx1 platform, was the designated vaccine for the study center during the enrollment period. The authors recently demonstrated a favorable safety profile of COVISHIELD when assessed up to 7 days after the second dose. 1 Here, we report the preliminary findings regarding our secondary outcome measure of postvaccination SARS-CoV-2 infections. The data are based on at least 2 months of follow-up since the second dose of vaccine in enrolled participants who could be successfully contacted telephonically.

The study included all vaccine recipients who provided consent and were enrolled at the time of receiving the first or second dose of the COVISHIELD vaccine. The recipients included predominantly medical and paramedical personnel as they were the initial beneficiaries of vaccine roll-out. In the later stages of enrollment, elderly non-healthcare workers who visited the study center for vaccination were also enrolled. Baseline demographic details of each participant were collected in a pre-designed case report form. 1 Enrollment was continued till the target sample size (n = 1650) was reached. As part of the ongoing prospective observational study, each participant is being monitored telephonically at specific intervals following the second dose, for a total duration of 1 year (study duration). Those who received only one dose are also being followed up similarly. For the secondary objective, details pertaining to development of COVID-19 such as symptoms, reverse-transcription polymerase chain reaction (RT-PCR) positivity, or rapid antigen test positivity for SARS-CoV-2 at any time following vaccination, need for hospitalization, and oxygen requirement details were collected. In case of deaths of the vaccine recipients, telephonic ascertainment of the cause of death was done using information collected from family members, and a request was made to provide medical certification documents. This interim analysis is being performed after at least 2 months of follow-up since the second dose.

COVID-19 cases were defined as "confirmed" and "suspect" based on investigators' assessment and guided by recommendations issued by the Ministry of Health and Family Welfare, Government of India. 2 

Ethical approval was obtained from the ethics committee of the Institute of Medical Sciences, Banaras Hindu University. No human experimentation was performed. Written informed consent was taken from all participants in this observational study.

Among 1650 enrolled vaccine recipients, 1500 participants of the study (female/male: 472/1028) completed at least 2 months of follow-up, after the second dose (baseline characteristics in Table 1 ).

Among these 1500, 1435 participants received both doses and 65 received only one dose.

In single-dose recipients (n = 65), laboratory-confirmed SARS-CoV-2 infection was observed in 27 individuals (41.5%). Two individuals (3.1%) were labeled as "suspects," and one (1.5%) was an RT-PCR negative suspect. Severity-wise, infections were mild in 21 out of 30 (70%) cases.

Three individuals (10% of cases, 4.6% of vaccinees) required hospitalization for oxygen requirement (details in Table 1 ). Two deaths were observed in this group, one in an elderly male with pre-existing coronary artery disease who died because of an unspecified cardiac event following recovery from COVID-19, and the other in an elderly male with comorbid diabetes and congestive heart failure who succumbed to unspecified post-COVID-19 complications. Details of both events were based on history provided by family members (Table S1 ). Table 1 ). Two deaths were reported in this group. One was a middle-aged man with comorbid diabetes who developed cellulitis of the lower limb leading to sepsis and encephalopathy and died due to multiorgan failure. He was assessed twice for SARS-CoV-2 infection but tested negative. The other death was of a healthcare worker with comorbid diabetes and hypertension who died of an unspecified cardiac event. Details of both events were based on history provided by family members (Table S1) . Abbreviations: ASD, atrial septal defect; CAD, coronary artery disease; COPD, chronic obstructive pulmonary disease; ILD, interstitial lung disease; RHD, rheumatic heart disease; RT-PCR, reverse-transcriptase polymerase chain reaction.

in April. 10 Our study design did not incorporate a lab component to determine variants in breakthrough cases and routine determination of variants is not performed in most institutes in India. The data from

Varanasi included samples tested at our institute, but being for general surveillance, these do not necessarily represent our participants. Internationally, an outbreak of the delta variant was reported following the first dose of VAXZEVRIA (also ChAdOx1 based) in an elderly care home in London. 11 A reduced protection against the delta variant has been shown for the ChAdOx1 nCoV-19 vaccine recently. 12, 13 Other potential explanations for the discrepancy in the rate of occurrence of SARS-CoV-2 infection between our study and other

Indian studies can be related to the study designs and regional var- in-patients, often using only N95 masks while managing out-patients.

As the ongoing study was primarily focused on adverse events following immunization (AEFIs) and enrolled only vaccinated individuals, the secondary outcome results lack a control unvaccinated group. Hence, we cannot comment upon the effectiveness of vaccines against infection, hospitalization, and death. A separate study has been initiated by the authors to analyze this aspect. Compared to a single dose of the COVISHIELD vaccine, two doses provided 41% efficacy against COVID-19 and 86% efficacy in preventing severe disease.

The 

The authors declare that there are no conflict of interests.

Generated idea, designed study protocol, supervised data collection, 

Since this is a preliminary analysis of a currently ongoing longitudinal study, associated data may be made available by the corresponding author on request.

ORCID Sumit Jaiswal https://orcid.org/0000-0002-0087-6235

A prospective observational safety study on ChAdOx1 nCoV-19 corona virus vaccine (recombinant) use

in healthcare workers-first results from India

Ministry of Health and Family Welfare Government of India. Updated clinical management protocol for COVID-19

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Effectiveness of the Pfizer-BioNTech and Oxford-AstraZeneca vaccines on covid-19 related symptoms, hospital admissions, and mortality in older adults in England: test negative case-control study

Vaccine effectiveness of the first dose of ChAdOx1 nCoV-19 and BNT162b2 against SARS-CoV-2 infection in residents of long-term care facilities (VIVALDI study)

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Reduced sensitivity of SARS-CoV-2 variant Delta to antibody neutralization

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Occurrence of COVID-19 in priority groups receiving ChAdOx1 nCoV-19 coronavirus vaccine (recombinant): A preliminary analysis from north India