Vial of Moderna's COVID vaccine
Vial of Moderna's COVID vaccineReuters

With the Omicron variant of the coronavirus spreading through multiple countries with verified cases in Israel too, many have been reassured by statements made by doctors dealing with a widespread outbreak in South Africa, indicating that the strain seems much milder than previous dominant variants such as Delta.

However, in comments made to UK members of Parliament today, Dr. Paul Burton, chief medical officer at Moderna, struck a warning note.

“I do not think Omicron is a milder, less severe version of the current virus,” he told the Parliamentary committee on science and technology, as quoted by The Guardian.

“The idea it will push Delta out of the way and take over may occur in the future, but I think in the coming months these two viruses are going to co-exist, and Omicron, which I would maintain is actually a severe disease, will now infect people on a background of very, very strong Delta pressure.

“It will also lead to a situation where individuals will become co-infected … which gives the opportunity for this virus to further evolve and mutate which is a concerning and worrying situation,” he added.

“We certainly don’t have to panic as we have many, many tools at our disposal, and we’ve learnt so much about this virus over the last two years, and we can continue to fight it, but I think Omicron poses a real threat,” he warned.

“When you look at the data in South Africa, about 15% of people who are hospitalized are in the intensive care unit, and while there’s variability, if you look back earlier in the year, at a time of Delta surge in August, those numbers are about the same, 15%.

“So while the mortality rate we are seeing right now is mercifully lower, I think as a disease it is a very fit virus and it’s severe.”

Burton added that within the next few days, data should be available indicating to what extent the Moderna mRNA booster shot improves protection against the Omicron variant.

Meanwhile, vaccine expert Shabir Mahdi of the University of the Witwatersrand suggested a possible reason for the differing experiences of South African and other countries. In an interview with the Global Health Crisis Coordination Center, Mahdi pointed out that over 70 percent of South Africa's population is believed to have previously contracted some variant of the coronavirus, which is what is providing them with enhanced protection against Omicron.

If Mahdi's ideas are substantiated by research, they would indicate a far superior protection provided by prior infection than that provided by vaccination. Many of the Omicron cases confirmed in the world have been discovered in fully vaccinated individuals.