The Omicron variant is less likely to cause long-term covid than Delta, according to a study published in the scientific journal The Lancet. In practice, people infected with the variant are less than half as likely.
To arrive at this discovery, the team of researchers used data collected through the ZOE COVID app, which stores information about the health of the UK population, in addition to positive tests for covid-19.
In all, about 56,000 individuals participated in the analysis. Of these, 41,000 tested positive for the disease last year, when Delta was the dominant variant. Of those infected in the Ômicron-dominated period, about 4.5% had symptoms that lasted longer than four weeks, compared with 10.8% of participants with Delta.
However, it is worth noting that the ZOE study mainly included people who caught the omicron BA.1 subvariant, as it only looked at people who had been infected until February 10, before other subvariants of omicron emerged.
In any case, the authors comment that severe covid-19 is more likely to lead to lasting symptoms and the Ômicron variant has been causing milder illness than the earlier variants, which justifies the result.
The WHO defines long-term covid as “a post-covid condition occurring in individuals with a history of probable or confirmed SARS CoV-2 infection, usually 3 months after the onset of symptomatic covid-19, and lasting for at least 2 months.”
Previously, Fiocruz followed 324 patients who developed long-term covid, and reached 23 symptoms that accompany the condition. Among them, fatigue, cough, difficulty breathing, loss of smell or taste, headache, red eyes, insomnia and even anxiety.
The good news is that the vaccine reduces the chance of long-term covid even if applied after infection, as a team of scientists pointed out last May. To reach this statement, more than 28 thousand individuals were analyzed.
Source: The Lancet, New Scientist