“Currently, there is no reason for panicking, as we don’t see severely ill patients,” Dr. Angelique Coetzee, chair of the South African Medical Association, told the Telegraph. Coetzee said COVID-19 patients infected with Omicron most often complain of “severe fatigue” for one or two days combined with headaches and body aches before their conditions improve. She said some patients also experience a dry cough or scratchy throat.

The first known Omicron specimen was collected in Botswana early this month, but Coetzee was the first doctor in South Africa to flag the emergence of the variant to local authorities.

Public health experts say it is far too early to make firm proclamations about the severity of Omicron based on Coetzee’s early anecdotal data. Coetzee herself explained that the vast majority of the patients she saw were under the age of 40 and therefore less susceptible to severe infections to begin with.

Meanwhile, there is little or no data regarding how many Omicron patients have been partially or fully vaccinated or previously infected with another variant of COVID-19. Experts also don’t know how deadly Omicron may be among more vulnerable populations.

The World Health Organization (WHO) urged caution in assessing whether the Omicron variant makes COVID patients as sick as past strains. On Sunday, the agency said it is “not yet clear” whether Omicron is more transmissible or severe than previous variants like Delta. The WHO also said it may be “days or weeks” before more credible data emerges regarding the variant.

But emerging reports about Omicron producing mild cases—at least so far—is encouraging news to public health experts globally.

“The early information about severity of illness is reassuring,” says Catherine Bennett, chair in epidemiology at Deakin University in Australia. “So far, we’re not hearing anything to really alarm us.”

In Israel, which banned foreigners from entering its borders for two weeks from Sunday owing to the new variant, health officials said they were concerned about early reports regarding the potential for Omicron to be highly transmissible but optimistic about its potentially producing less severe infections.

“If it continues this way, this might be a relatively mild illness compared to the Delta variant, and, paradoxically, if it takes over, it will lead to lower infection rates,” Dror Mevorach, head of the coronavirus department at Hadassah University Hospital Ein Karem, told Israeli newspaper Haaretz.

For now, Bennett says, the world needs to keep its focus on the Delta variant, currently the predominant strain of COVID-19 globally. Getting vaccinated and boosting populations remains the key way to limit the spread of the virus and make it less lethal, she said.

“If it turns out Delta does have more severe illness than the Omicron, we don’t want to take our sights off Delta and then find out that [Omicron] is quite benign,” Bennett says. “If it causes less severe illness [than Delta], that’s a big relief.”