he omicron variant of the coronavirus has been dominant in the U.S. since December, but the version of omicron that drove the major infection surge during the winter now accounts for less than 2 percent of new cases.
A more transmissible subvariant, BA.2, accounts for around three-fifths of cases. And BA.2, in turn, has spawned its own sub lineage, BA.2.12.1, which has been gaining steam: It rose from 7 percent of cases in early April to 36 percent by the end of the month.
So far, the key difference between the newer versions of omicron and the one that previously rocketed through the U.S. is transmissibility. The White House’s chief medical adviser, Dr. Anthony Fauci, has estimated that BA.2 is 50 percent more transmissible than the original omicron lineage. The recent gains BA.2.12.1 has made suggest it has a further advantage over its predecessor.
But the cold like symptoms vaccinated and boosted people feel as a result of an omicron infection are mostly the same regardless of the subvariant.
“The omicron symptoms have been pretty consistent. There’s less incidence of people losing their sense of taste and smell. In a lot of ways, it’s a bad cold, a lot of respiratory symptoms, stuffy nose, coughing, body aches and fatigue,” said Dr. Dennis Cunningham, the system medical director of infection control and prevention at Henry Ford Health in Detroit.
Symptoms of the BA.2 subvariant
The Zoe COVID Symptom Study in the U.K. has enabled hundreds of thousands of people to self-report their symptoms through smartphone apps.
One of the apps’ co-founders, Tim Spector, a professor of genetic epidemiology at King’s College London, said that based on Zoe data, a runny nose is still the most common symptom of omicron, followed by fatigue, sore throat, sneezing, headache, cough and hoarse voice.
“The changes from BA.1 to BA.2 have been quite subtle — perhaps runny nose and fatigue [are] going up,” he said.