Maria Van Kerkhove, the World Health Organization's technical lead on COVID, has warned against referring to the Omicron variant as "mild" amid reports that it isn't yet causing as much severe disease as in previous waves.
Her comments came after early reports suggested that the new variant of concern appeared to be causing milder symptoms than some other forms of the virus.
One such report from the South African Medical Research Council last weekend stated that, based on a snapshot of 42 patients in a hospital ward in Tshwane, South Africa, on December 2, 70 percent weren't dependent on oxygen at that time.
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The report said it was "a picture that has not been seen in previous waves" in which "the COVID ward was recognizable by the majority of patients being on some form of oxygen supplementation."
Meanwhile Dr Anthony Fauci, head of the U.S. National Insitute of Allergy and Infectious Diseases (NIAID), told the AFP news agency that Omicron "almost certainly is not more severe than Delta"
However, speaking to New Scientist magazine this week, Van Kerkhove warned that "people will die" from Omicron, adding: "Saying 'it's only mild' is very dangerous.
"If it is more transmissible than delta, there will be more cases, more hospitalisations and more deaths."
Van Kerkhove expressed similar concerns during a WHO press briefing on Wednesday. In it, she acknowledged that there were "indications of more mild disease" from South Africa, but noted that she "wanted to caution against any conclusions about [the] severity of Omicron yet, because right now we really have anecdotal information. We don't really have studies yet."
And last weekend, Jerome Adams, a former U.S. Surgeon General, stated that a substantially higher transmission could cancel out lower severity in any case.
Severity is only one aspect of Omicron that we don't know a lot about so far. Scientists are keen to get a clearer picture of how well the variant can resist vaccines and how transmissible it is.
Some early information has been released regarding Omicron and vaccines, suggesting that vaccines do elicit some neutralization activity against the variant despite its high resistance.
Two studies—one in South Africa from the Africa Health Research Institute and one from Pfizer/BioNTech—suggested that a booster shot would increase patients' capacity to combat severe disease from Omicron.
Meanwhile the U.S. is experiencing a sharp rise in COVID cases overall this week, with a seven-day average of just over 117,000 daily new cases recorded on December 7, according to Centers for Disease Control and Prevention (CDC) data, marking an increase from 86,318 on December 1.
There was also a seven-day average of 1,097 daily deaths on December 7, the CDC data showed, up from 842 on December 1.
Maria Van Kerkhove, COVID technical lead for the WHO, speaking at a press conference in Geneva in July, 2020. Van Kerkhove has warned that much about Omicron is still unknown.Maria Van Kerkhove, COVID technical lead for the WHO, speaking at a press conference in Geneva in July, 2020. Van Kerkhove has warned that much about Omicron is still unknown.Fabrice Coffrini/Pool / AFP / Getty