The WHO says the SARS-Cov-2 virus variant is “highly divergent with a high number of mutations,” some of which are “concerning and may be associated with immune escape potential and higher transmissibility. However, there are still considerable uncertainties.”
The international body says that based on limited evidence, Omicron appears to have a growth advantage over the prevalent Delta variant, citing the example of the United Kingdom (UK).
“Whether Omicron’s observed rapid growth rate in countries with high levels of population immunity is related to immune evasion, intrinsic increased transmissibility, or a combination of both remains uncertain.”
Data on the severity of the variant remains limited says the WHO, while noting that cases reported in South Africa and Europe have so far been mild and asymptomatic.
With regards to protection conferred by vaccines, the data is again still limited, but preliminary evidence along with mutations in the variant “suggests a reduction in vaccine efficacy against infection and transmission associated with Omicron,” says the technical briefing.
The WHO also says that based on a few studies of limited sample size of those vaccinated and with natural immunity, individuals had lower neutralization activity compared to other strains of the virus.
On the same day the WHO was releasing its briefing on Omicron, South Africa’s Health Minister struck a reassuring tone as cases and hospitalizations are surging.
“Preliminary data does suggest that while there is increasing rate of hospitalisation ... it looks like it is purely because of the numbers rather than as a result of any severity of the variant itself, this Omicron,” Joe Phaahla said, according to Reuters.
It’s a different scenario in the UK, with its Prime Minister Boris Johnson warning about a “tidal wave” of Omicron and saying two doses of vaccine is no longer sufficient.
The UK raised its COVID-19 alert level to 4 on a scale of 5 on Dec. 12 due to Omicron fears, and encouraged everyone above 18 to receive a vaccine booster, with Johnson saying “I’m afraid it is now clear that two doses of vaccine are simply not enough to give the level of protection we all need.”
UKHSA said the hospitalized ranged between 18 and 85 years old and the majority had received two doses of vaccination.
“Hospitalisations always lag a few weeks behind infections, therefore it isn’t surprising that we have started to see people being admitted to hospital with the Omicron variant,” stated Dr. Susan Hopkins, chief medical adviser at the UKHSA.
