ICU units in South Africa are not full, according to Dr. Angelique Coetzee, who discovered Omicron.
She noted that while she understands the British government's Plan B measures, there is "no need" to put millions back in lockdown.
During a visit to a vaccine centre in Paddington, west London, this morning, the PM dismissed concerns about Omicron.
Sadly, Omicron is causing hospitalizations and at least one patient has died from Omicron.
We need to put aside the assumption that this is a gentler virus and just acknowledge the speed at which it spreads across the population. So we should all get our boosters.'
Dr Coetzee said all experts in South Africa – which was attacked first and has the most data – would ‘tell you the same storey'.
‘This is our fourth week, there's no reason you can't trust us when we say “it's mild disease,” she told LBC.
There will be sick patients, but the most are moderate.
‘These mild cases do not require hospitalisation. These patients recover in about five days, whether they are children or elderly, vaccinated or not. This is real life, this is what we are experiencing. Everyone feared catastrophic sickness two or three weeks later, but it hasn't happened in primary care.
‘It's incredibly contagious — you may have a million instances, or more.
‘But the sickness is minimal. Our ICU beds are empty. One or two of our hospitals report a little increase.'
South Africa has curfews and bans on large events, but Dr Coetzee says the case rate is already reducing.
Not known are the patient's medical history or vaccination status in the UK who died from Omicron.
Mr Johnson has promised to administer booster shots to all adults by the end of the year.
Many NHS appointments will be postponed over the next two weeks as clinicians focus on booster shots.
Yesterday saw 1,239 new Omicron infections in the UK, a daily record and nearly quadruple the previous high on Saturday.
Efforts to stop the spread of the virus increased Monday in England.
The UK Covid Alert Level has been raised to four, and specialists are advising people to cut social contacts.
Mr Johnson said Britain must ‘urgently fortify our wall of vaccine protection' once the new variety was released.
The daily coronavirus cases in South Africa hit a record high of 37,875 yesterday, with almost 19,000 unreported owing to ‘IT problems'.
In the last 24 hours, there have been 18,035 new instances detected, plus 19,840 retrospective cases due to ‘reporting delays'.
While the daily caseload is still below the UK's, 48,854 new infections were registered yesterday.