The study is based on epidemiological, clinical, and genome sequence analysis of 264 cases since the day Omicron was designated as VoC by WHO.
Out of the 264 cases included during the study period, 68.9 % were identified as Delta and its sub-lineages while 31.06 % were Omicron with BA.1 as the predominant sub-lineage (73.1 % ).
Most of the Omicron cases were asymptomatic (nP,61 % ) and did not require any hospitalizations. A total of 72 (87.8 % ) cases were fully vaccinated.
At least 39.1 % had a history of travel or contact while 60.9% showed community transmission. A steep increase in the daily progression of Omicron cases with its preponderance in the community was observed from 1.8 % to 54 %, the study highlighted.
The study observed that young adults and males were infected more in comparison to children and the elderly population which could be due to more socializing and close connections than other mentioned groups.
The results suggest a large reduction in protection against the Omicron variant of the COVID-19 infection as 87.8 % population got reinfected after full primary vaccination thus implying increased breakthrough infections. The results suggest a large decrease in protection from the vaccine or natural immunity against COVID infections caused by the Omicron variant.
This is a prospective study where respiratory specimen from all RT-PCR confirmed positive cases between November 25 to December 23 collected from five districts of Delhi were subjected to whole-genome sequencing. Complete demographic and clinical details were recorded.
This emphasizes the urgent need for a booster vaccination and will warrant implementing non-pharmaceutical interventions along with the installation of rapid detection strategies for asymptomatic carriage in high-risk transmission populations especially with those having comorbidities.
The study has said that the majority of Omicron patients (60.9 % ) had no documented international travel history or contact hence evidently they acquired the infection locally, thus signifying the community spread and imposing further challenges in controlling the virus.
Source: IANS
