A man is tested for Covid with a swab in Northern Ireland
(Picture: PA Archive)Omicron symptoms fade in half the time of the common cold in people who have received a booster jab, according to a new study.
Researchers from King’s College London (KCL) and the ZOE Covid App studied 62,000 vaccinated people and found that those who were triple jabbed experienced omicron symptoms for around 4.4 days.
In comparison, those who had not received their booster jab suffered omicron symptoms for 8.3 days, rising to 9.6 days for the delta variant.
Symptoms of the common cold last between seven and 10 days, according to the NHS.
The study, published in The Lancet, found that the loss of a sense of smell appeared in just 17 per cent of omicron cases – compared to 52.7 per cent of delta cases. The symptom was previously a key sign of infection in previous variants.
Those infected with omicron were more likely to suffer from a sore throat and hoarse voice, according to the study. Other debilitating symptoms such as brain fog, dizziness and headache were also found to be “significantly less prevalent” in omicron patients.
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.”
Elsewhere, the study found that omicron patients were 25 per cent less likely to be hospitalised than delta patients. One in 50 omicron patients were hospitalised with the disease compared with one in 38 infected with delta.
Omicron became the dominant variant in the UK in December 2021, sparking the largest wave of infection so far during the pandemic. Despite its high transmissibility, the variant has a much lower rate of hospitalisation than the original variant of Covid – in particular among those who have been fully vaccinated.
Researchers studied users of the ZOE Covid symptoms tracker app and who were infected between June 1 and November 27 last year, when the delta variant was dominant. This was compared with data from December 22 last year to January 17, 2022 – when omicron infections were on the rise.
Dr Cristina Menni, King’s College London, said that scientists had observed 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 i.e. fever, persistent cough, loss of smell, our results point to a different selection of symptoms that may indicate infection,” she said.
“To protect others, it is still important to self-isolate for five days as soon as you see any symptoms.”
