Omicron and Delta symptoms are different, study confirms

While fever, persistent cough and loss of taste and smell defined Delta, sore throat was more prevalent symptom in Omicron patients

Omicron BF.7, coronavirus, Mansukh Mandaviya, international passengers
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People who have the Omicron Covid variant tend to have symptoms for a shorter period, a lower risk of being admitted to hospital and a different set of symptoms from those who have Delta, The Guardian report quoted a study published in the medical journal Lancet.

The study confirmed that while Omicron was highly transmissible, its effects were much less severe than the earlier Delta variant. Not only that, Omicron symptoms were different than those of Delta. While fever, persistent cough and loss of taste and smell defined Delta, symptom of sore throat was more prevalent in Omicron patients.

“It is a lesson that we need to be far more flexible in thinking what the virus is and how it is going to present than we have been, certainly in the UK,” said Prof Tim Spector, co-author of the research from King’s College London, The Guardian reported. The study will be presented at the European Congress of Clinical Microbiology & Infectious Diseases.

Study parameters


The researchers matched almost 4,990 participants who had a confirmed Covid infection between June 1 and November 27, 2021 – when Delta was the most prevalent variant – with 4,990 individuals who reported an infection between December 20, 2021, and January 17, 2022, when Omicron dominated. The matching was based on age, sex and number of vaccine doses taken by the patients, The Guardian report said.

The results suggested only 17 per cent of people who had Covid when Omicron dominated lost their sense of smell, compared with 53 per cent when Delta dominated. However, a sore throat and hoarseness was common among the Omicron patients.

“[It] should alert us what to look out for when there will inevitably be the next variant,” the paper quoted Spector, who further said action needs to be quicker in the future.

The newspaper quoted another expert, David Strain, a senior clinical lecturer at the University of Exeter Medical School, who was not involved in the study, as saying that with the Omicron variant BA.2 the picture has changed again. “People in hospital are staying in hospital for longer and staff are testing positive for longer, so it is longer before they can return to work,” he said.