Prevalence and Pathogenicity of Omicron Varian

Abstract

The surge of the Omicron variant has been studied in overall India, Delhi and Mumbai. The increase in the percentage share of the Omicron strain in total registered cases resulted in a surge of daily new infections. The pathogenicity of Original, Delta, and Omicron variants has been compared using the data collected at the Max Healthcare network in India. The Omicron wave was the least severe of all three waves. The third Omicron wave did not cause much damage due to hybrid immunity generated in the population as a result of vaccination and previous SARS-CoV-2 infection. The low pathogenic nature of the Omicron virus is also the reason for the less severe illnesses the variant caused. Hospitalization during the Omicron wave was just 10% of the Delta wave. The percentage of patients who needed oxygen support was the least during the Omicron wave (23.4%) followed by the Original (63%) and the Delta variant (74%). The less severe nature of the Omicron wave gave the hope of recovering from the deadly devastating COVID-19 pandemic. The symptoms of “long COVID” patients have been compared during all three waves. Nearly the same number of the patients at 5.3% and 5.16% had health issues during Original and Omicron waves, respectively whereas during the Delta surge 5.9% of patients with “long COVID” had symptoms.

In Silico Analyses Indicate a Lower Potency for Dimerization of TLR4/MD-2 as the Reason for the Lower Pathogenicity of Omicron Compared to Wild-Type Virus and Earlier SARS-CoV-2 Variants

“…There is increasing evidence that Omicron, despite a significantly higher transmissibility and infectivity, shows a significantly lower rate of severe clinical courses compared to previous VoCs, including the Delta variant, i.e., the last VoC before Omicron [70]. Early reports on the lower number of severe clinical outcomes in Africa [1,2] are concordant with published studies from other geographical areas on the Omicron pandemic, such as the UK and USA, and have been confirmed by recent reports covering recent Omicron variants, including BA1 (B.1.1.529), BA2, BA4, BA5, XBB1.5 and EG5.1-all showing higher transmissibility but significantly lower pathogenicity [71][72][73][74][75][76][77][78][79][80].…”

“…Overall, these studies using different Omicron isolates have demonstrated a shift in cellular tropism with attenuated lung disease in rodents and cats, supporting human clinical data [1,2,[71][72][73][74][75][76][77][78][79][80]. Still, the molecular mechanisms responsible for this reciprocal change in tropism in the Omicron variant are not completely defined so far.…”

COVID-19 Aftereffects (Long COVID) Associated with Wuhan, Delta, and Omicron Variants Reported in Japanese Hospitals

“…The Omicron surge in the Indian state of Karnataka has been studied [10] in relation to the % share of the Omicron lineage out of the total infection. To determine the pathogenicity and virulence of all three variants (original Wuhan, Delta, and Omicron), the data from Max Hospital (India) were studied [11]. The Omicron variant was found to be less harmful than the Wuhan and Delta strains when pathogenicity was compared in terms of CFR and hospitalization rate.…”

4th Serosurvey of Tamil Nadu: Infection and Vaccine Generated Hybrid Immunity

“…In terms of CFR (case fatality rate) and hospitalization rate, the Omicron is less pathogenic than the Wuhan and Delta strains. The data reported from the Max Hospitals (India) of all three pandemic waves were analyzed [10]. The Omicron wave was the least damaging of all three waves.…”