Expanding repertoire of SARS-CoV-2 deletion mutations contributes to evolution of highly transmissible variants.

The emergence of highly transmissible SARS-CoV-2 variants and vaccine breakthrough infections globally mandated the characterization of the immuno-evasive features of SARS-CoV-2. Here, we systematically analyzed 2.13 million SARS-CoV-2 genomes from 188 countries/territories (up to June 2021) and performed whole-genome viral sequencing from 102 COVID-19 patients, including 43 vaccine breakthrough infections. We identified 92 Spike protein mutations that increased in prevalence during at least one surge in SARS-CoV-2 test positivity in any country over a 3-month window. Deletions in the Spike protein N-terminal domain were highly enriched for these 'surge-associated mutations' (Odds Ratio = 14.19, 95% CI 6.15-32.75, p value = 3.41 × 10-10). Based on a longitudinal analysis of mutational prevalence globally, we found an expanding repertoire of Spike protein deletions proximal to an antigenic supersite in the N-terminal domain that may be one of the key contributors to the evolution of highly transmissible variants. Finally, we generated clinically annotated SARS-CoV-2 whole genome sequences from 102 patients and identified 107 unique mutations, including 78 substitutions and 29 deletions. In five patients, we identified distinct deletions between residues 85-90, which reside within a linear B cell epitope. Deletions in this region arose contemporaneously on a diverse background of variants across the globe since December 2020. Overall, our findings based on genomic-epidemiology and clinical surveillance suggest that the genomic deletion of dispensable antigenic regions in SARS-CoV-2 may contribute to the evasion of immune responses and the evolution of highly transmissible variants.

Normative blood pressure data for Indian neonates.

OBJECTIVE: To establish the normative blood pressure (BP) values in healthy Indian neonates using oscillometric method, and to develop BP percentile charts. DESIGN: Prospective observational study. SETTING: Neonatal unit of a teaching hospital in Eastern India. PARTICIPANTS: 1617 hemodynamically stable inborn neonates without birth asphyxia, major congenital anomaly, maternal complications (e.g. preeclampsia, hypertension, diabetes) or critical neonatal illness. PROCEDURE: Quite state measurements of systolic BP (SBP), diastolic BP (DBP) and mean arterial pressure (MAP) were recorded by oscillometric method on day 4, 7 and 14 of postnatal life. The averages of three readings at 2-minute intervals were used. RESULTS: Percentile charts (providing 5th, 10th, 25th, 50th, 75th, 95th, and 99th percentile values) have been developed. SBP, DBP and MAP showed a steady rise from day 4 to day 14, and were comparable between males and females, but were significantly lower in preterms than in term neonates. CONCLUSIONS: Normative neonatal BP data along with gestational age-wise percentile charts shall be of help for decision-making and planning for sick newborns.