File image of a man getting a Covid vaccine
(Picture: PA)Those who had recieved a booster vaccine experienced symtoms of the Omicron variant for half the time of those who had not had the third jab, a study has found.
People who had a third shot of the vaccine reported an average of 4.4 days with symptoms of Omicron, according to research from King’s College London, published in the Lancet.
The study, which analysed 62,000 vaccinated people, found those without a booster vaccine reported symptoms lasting 8.3 days.
Professor Ana Valdes, an honorary professor at King’s College London, said: “Although there is still a wide range of duration and severity of symptoms with Omicron, for vaccinated individuals we find on average a shorter duration of symptoms.
“This suggests that the incubation time and period of infectiousness for Omicron may also be shorter.”
The study also found symptoms of the Delta variant lingered for 7.7 days for the boosted and 9.6 days on average for those with two jabs.
Omicron patients were 25 per cent less likely to be admitted to hospitals than Delta patients, the research found.
Fewer than one in 50 Omicron patients - 1.9 per cent - ended up in hospital, compared with one in 38 of those infected with Delta.
According to the study, there was a difference in reported symptoms between the two variants.
Only 17 per cent reported a loss of smell with the Omicron variant compared with 53 per cent of those infected with Delta.
Dr Cristina Menni, from King’s College London, said: “We observe a different clinical presentation of symptoms in those infected with Omicron compared to Delta.
“As we are moving even further away from the average patient having UK government ‘core’ symptoms - for example, fever, persistent cough, loss of smell - our results point to a different selection of symptoms that may indicate infection.
“To protect others, it is still important to self-isolate for five days as soon as you see any symptoms.”
Researchers studied people who signed up to the ZOE Covid symptoms tracker app and who tested positive between June 1 and November 27 last year, when Delta was dominant, and from December 22 2021 to January 17 2022, when Omicron cases spiked.
Data from the ZOE Covid study reported a further 304,577 new symptomatic cases of Covid across the UK on April 6.
It comes as Boris Johnson refused to rule out further lockdowns.
Asked about the possibility of another lockdown, he said: “I can’t rule it out. I can’t say we wouldn’t be forced to do non-pharmaceutical interventions again of the kind we did.”
