Omicron lasts three days less than Delta for boosted: study

LAS VEGAS, NEVADA – DECEMBER 21: OptimuMedicine registered nurse Allison Anderson (L) gives Chuck Struckness of Nevada a Pfizer-BioNTech booster shot at a pop-up COVID-19 vaccination clinic at Larry Flynt’s Hustler Club on December 21, 2021 in Las Vegas, Nevada. With the Omicron variant on the rise, the club partnered with Immunize Nevada to launch “Boobs for Boosters,” its second vaccination event to offer first or second Pfizer-BioNTech, Moderna or Johnson & Johnson shots, along with booster shots and regular and high-dose flu shots. Those who received COVID-19 booster shots received USD 200 gift cards to the company representing the club and dinner for two at its rooftop restaurant. Ethan Miller/Getty Images/AFP (Photo by Ethan Miller / GETTY IMAGES NORTH AMERICA / Getty Images via AFP)


PARIS, France (AFP) — People who are vaccinated and have had a booster shot against Covid-19 recover from symptoms from the Omicron variant more than three days earlier than those with the Delta variant, a study said Friday.

The study also found that people with Omicron are significantly less likely to lose their sense of smell, and confirmed previous research that it is less severe.

To find out the differences in how Omicron and Delta make sufferers sick, researchers used a free smartphone app called ZOE on which more than 63,000 vaccinated people in Britain aged 16-99 self-reported their Covid symptoms between June 2021 and January 2022.

For those with two vaccine doses plus a booster, symptoms from Omicron lasted 4.4 days, compared to 7.7 for Delta — a difference of 3.3 days.

People who had two doses but no booster shot saw Omicron symptoms clear up in 8.3 days, compared to 9.6 days for Delta, according to the study published in the Lancet medical journal.

An illustration picture taken in London on December 2, 2021 shows four syringes and a screen displaying the word ‘Omicron’, the name of the new covid 19 variant, and an illustration of the virus. (Photo by Justin TALLIS / AFP)

The swifter recovery suggests “that the period of infectiousness might be shorter, which would in turn impact workplace health policies and public health guidance,” the researchers said.

The study, which will be presented at the European Congress of Clinical Microbiology and Infectious Diseases in Lisbon later this month, also found that only 17 percent of those with Omicron lost their sense of smell, compared to 53 percent for Delta.

However people with Omicron had a 55-percent increased risk of getting a sore throat, and were 24 percent more likely to develop a hoarse voice.

The study also found that Omicron patients were 25 percent less likely to be admitted to hospital.

Study author Cristina Menni of King’s College London said it was the first peer-reviewed paper with a large number of participants that looked at the different symptoms of the two variants.

While the study covered a period before the Omicron BA.2 variant swept the world, “recent data from the app show no change in symptoms in BA.2 compared to BA.1,” she told AFP.


© Agence France-Presse