International omicron doubling

Link for free download of John's two text books,

Campbell's Pathophysiology Notes, Amazon orders for the UK,
Campbell's Physiology Notes
the disease is mild in almost all of the cases seen so far,

Dr Rochelle Walensky, CDC

75% of US cases vaccinated

Scotland, 'tsunami' of Omicron

Families in Scotland, to self-isolate for 10 days if one member tests positive,

regardless of their vaccination status and even if they initially get a negative PCR test

UK Government working on a 'Plan C'

UK, Health Security Agency

Omicron is displaying a significant growth advantage over Delta,

likely to outcompete Delta in the UK and become the dominant variant.

If the growth rate and doubling time continue,

at least 50% of coronavirus (COVID-19) cases to be caused by Omicron variant by mid-December

One million by end of December

1% = 10,000

Omicron displays a reduction in protection offered by having had a previous infection or vaccination.

There is insufficient data to make any assessment of protection against severe disease,

or to assess the severity of illness caused by Omicron.

Further studies are underway in the UK and abroad.

Graph refs

SA. Live data, hospital patients who have tested positive

South Africa references

Weekly deaths in SA

Variants in SA

Hospital admissions from Omicron should be expected to follow soon (high confidence).

Though there remain some important uncertainties,

Early verbal reports indicate that hospitalisations due to Omicron are now increasing in South Africa.

The doubling time for new Omicron infections is currently around 3 days in England

It is unlikely to be any slower than a 5-day doubling time (high confidence)

Household studies show higher secondary attack rates (high confidence).

Why is omicron more transmissible?

Combinations of transmissibility and immune escape

Some early indications from South Africa suggest less severe disease in those hospitalised

A modest reduction in severity would not avert high numbers of hospitalisations if growth rates remained very high.

One thousand per day be end of month

The peak is highly likely to be higher than 1,000 to 2,000 Omicron hospital admissions per day without intervention

For it to be below this level there would need to be only a small degree of immune escape and very high protection from boosters against Omicron

With very rapid doubling times a large wave could occur leading to synchronous absences from work.

With lags of the order of two or more weeks,

and doubling times of the order of three days,

it is likely that, once hospitalisations begin to increase at a rate similar to that of cases,

four doublings (a 16-fold increase) or more could already be “in the system”

A greater role for airborne transmission
Ventilation, well-fitting masks and distancing or reduced density of people in indoor environments may be even more important.


In your talk about the Oslo party you embrace another wrong inference that many people like to believe,

that claims that viruses tend to become less lethal because “not killing their host” keeps the viruses in the host alive too

and enables the host to keep infecting, making the virus more contagious.

This claim may be contested even in the general case,

but it’s certainly wrong for SARS-COV 2 since as you pointed out many times –

the death of the victim almost always happens after he is no longer infectious

and this means that prolonging the life of the victim does not prolong the period of infectivity.
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