Today: 31 May 2025
21 December 2021
2 mins read

No evidence Omicron has lower severity than Delta variant

The yet-to-be-published study used data for all PCR-confirmed SARS-CoV-2 cases in England who had taken a COVID-19 test between November 29 and December 11, 2021…reports Asian Lite News.

There is “no evidence” that Omicron has a lower severity than the Delta strain, according to a study in the UK which also found that the new variant of coronavirus largely evades immunity from past infection or two vaccine doses.

The study by researchers from Imperial College London in the UK estimates that the risk of reinfection with the Omicron variant is 5.4 times greater than that of the Delta variant.

This implies that the protection against reinfection by Omicron afforded by past infection may be as low as 19 per cent, the researchers said.

“The study finds no evidence of Omicron having lower severity than Delta, judged by either the proportion of people testing positive who report symptoms, or by the proportion of cases seeking hospital care after infection,” the authors of the study said. “However, hospitalisation data remains very limited at this time,” they added.

The yet-to-be-published study used data for all PCR-confirmed SARS-CoV-2 cases in England who had taken a COVID-19 test between November 29 and December 11, 2021.

The research included people identified as having Omicron infection due to an S gene target failure (SGTF), as well as people with genotype data that confirmed Omicron infection.

Overall, 196,463 people without S gene target failure — those likely to be infected with another variant — and 11,329 cases with it were included in the analysis, as well as 122,063 Delta and 1,846 Omicron cases in the genotype analysis.

The results suggest that the proportion of Omicron among all COVID cases was doubling every two days up to December 11, the researchers said.

They estimate that the reproduction number (R) — the number of cases directly caused by an infected individual — of Omicron was above 3 over the period studied.

“This study provides further evidence of the very substantial extent to which Omicron can evade prior immunity given by both infection or vaccination,” said Neil Ferguson, a professor at Imperial College London.

“This level of immune evasion means that Omicron poses a major, imminent threat to public health,” Ferguson said in a statement.

Controlling for vaccine status, age, sex, ethnicity, asymptomatic status, region and specimen date, Omicron was associated with a 5.40 fold higher risk of reinfection compared with Delta, the study found.

The reinfection risk estimated in the current study suggests this protection has fallen to 19 per cent against an Omicron infection, according to the researchers.

They found a significantly increased risk of developing a symptomatic Omicron case compared to Delta for those who were two or more weeks past their second vaccine dose, and two or more weeks past their booster dose for AstraZeneca and Pfizer vaccines.

“Depending on the estimates used for vaccine effectiveness against symptomatic infection from the Delta variant, this translates into vaccine effectiveness estimates against symptomatic Omicron infection of between 0 per cent and 20 per cent after two doses, and between 55 per cent and 80 per cent after a booster dose,” the researchers added.

ALSO READ-GCC, UK vow to boost economic, security ties

Previous Story

Expo 2020 Tightens Covid Rules

Next Story

J&K inks deal with UCB to facilitate UT students

Latest from -Top News

World needs Dubai’s ambition: Morgan

Piers Morgan has hailed Dubai’s transformation as an example of what visionary leadership can achieve. British broadcaster Piers Morgan has praised the extraordinary ambition and vision of His Highness Sheikh Mohammed bin

Mohammed honours football champions

Ruler of Dubai hails players as role models during palace reception His Highness Sheikh Mohammed bin Rashid Al Maktoum, Vice President, Prime Minister of the UAE, and Ruler of Dubai, received the

Abu Dhabi sets 2050 energy vision

Abu Dhabi unveils AED400 billion energy roadmap, inked climate finance pact ahead of 2026 UN Water Conference Abu Dhabi has unveiled a sweeping strategic framework to transform its energy and water sector

Gargash: UAE’s pragmatism sets regional example

Anwar Gargash says the UAE stands as a beacon of what is possible when pragmatism and vision come together. As political instability, economic fragmentation and rapid technological change continue to reshape the

US flag returns to Damascus

Billions in energy deals and lifted sanctions mark Syria’s reintegration, as US reopens embassy and declares the war-torn nation “open for business” under new regional partnerships. The United States has reopened its
Go toTop

Don't Miss

Iran reports 1st Omicron case

Iran has reported its first case of the Covid-19 Omicron

Covid cases in Africa drops for first time since 4th wave

Weekly Covid-19 cases in Africa have dropped significantly and deaths