Omicron emergency
No one should be in any doubt, there is a tidal wave of Omicron coming
It is now clear that two doses of vaccine are simply not enough to give the level of protection we all need.
But the good news is that our scientists are confident that with a third dose, a booster dose, we can all bring our level of protection back up
At this point our scientists cannot say that Omicron is less severe
a wave of Omicron through a population that was not boosted would risk a level of hospitalisation that could overwhelm our NHS and lead sadly to very many deaths
Aged 18 and over, in England, third jabs from this week
Three months since second dose
A third booster dose prevents around 75% of people getting any Covid symptoms from Omicron
Live data, hospital patients who have tested positive
Omicron cases have now been found in hospital
Nadhim Zahawi
Warned of the danger of tens of thousands of hospitalisations,
even if omicron were to prove half as severe as delta
SARS-CoV-2 variants of concern and variants under investigation in England
Technical briefing 31
Data cut off, 6 December
260 confirmed cases of Omicron VOC-21NOV-01 (B.1.1.529),
Identified through sequencing or genotyping in England.
Additional possible cases identified through S gene target failure
Higher risk of transmission from secondary attack rates
Risk of household transmission from an Omicron index case compared to a Delta index case 3.2
Risk of a close contact becoming a secondary case, adjusted odds ratio 2.09
Household secondary attack
Omicron, 21.6%
Delta, 10.7%
Three to eight-fold increased risk of reinfection with the Omicron variant.
A 20 to 40-fold reduction in neutralising activity by Pfizer 2-dose vaccinee sera for Omicron
At least 10 fold loss of activity when compared to Delta
Greater reduction in activity was seen for AZ 2- dose sera
An mRNA booster dose resulted in an increase in neutralising activity irrespective of primary vaccination type
Data are urgently required on the durability of neutralising activity
A moderate to high vaccine effectiveness of 70 to 75% is seen in the early period after a booster dose.
With previous variants, vaccine effectiveness against severe disease, has been higher than effectiveness against mild disease
Lateral flow, similar sensitivity to detect Omicron compared to Delta
Modelling the potential consequences of the Omicron SARS-CoV-2 variant in England
Growth rate of the Omicron variant
Level of immune escape
Intrinsic transmissibility
Immune escape of Omicron
5.1-fold to 12.8-fold reduction in neutralisation relative to Delta
Intrinsic transmissibility
Omicron variant is growing in England at an exponential growth rate of r = 0.29 per day
This corresponds to a 2.4-day doubling time
Reproduction number Rt = 4.0
Generation interval of 5.5 days
Surge in SARS-CoV-2 transmission beginning in late December 2021
Infections exceeding peak levels recorded during the January 2021 wave in England
The most optimistic scenario, 1 December to 30 April in England
Omicron has low immune escape and booster jabs are highly effective
20.9 million infections
175,000 hospital admissions
24,700 deaths
Most pessimistic scenario, 1 December and 30 April in England
34.2 million infections
492,000 hospital admissions
74,900 deaths
Conclusions and discussion
Without the implementation of further control measures,
hospital admissions resulting from the Omicron wave of transmission,
could exceed the peak levels recorded in England during the previous winter wave in 2020-2021
In populations with high levels of immunity such as England and South Africa
Omicron variant has the potential to cause significant disruption
In populations with low levels of immunity such Africa
Omicron may or may not out compete delta
Link to free download of my 2 textbooks
Campbell’s Pathophysiology Notes, Amazon orders for the UK,
Campbell’s Physiology Notes
