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Thursday, 9 December 2021

Is Omicron more Transmissible But less Severe Than Delta?

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1) Update: 15 December 2021Detecting Omicron 
2) Update: 23 December 2021Omicron, lesser hospitalization
3) Update: 29 December 2021: Omicron in GauTeng,  SA 

8 August 2018

The preliminary hospital data released by the South African (SA) Medical Research Council (SAMRC) appears to suggest that thus far.  This article intends to keep track of the development of Omicron.

What has been found?

This chart released by SAMRC gives us a glimpse of what we say about Omicron as far as transmissivity  & severeness are concerned.

The chart is showing us the following picture.  It tells us Omicron is about 20% more transmissible but  6 times less severe in terms of death at the present moment.

Updated Chart (To be updated regularly)

The attached is superimposing the new cases and death charts taken from Our-World-in-Data.  It is for the whole of  SA and it is also showing that Omicron is more transmissible but less severe than the other variants.  Until further notice, this chart will be updated regularly or when there are many changes. 

The following chart is the situation in SA & Botswana where Omicron is the predominant virus to date.  Omicron's new cases in SA have risen and are about to break their last record.  The death rate still remains muted.

What Can We Expect?

Many are of the view that these preliminary findings cannot represent the real power of Omicron because Omicron is a new variant.   It might mutate & further develop into a more fearful variant in the future.   There is also a time lag between the death and the infection figures.  In other words,  we might expect Omicron to have more deaths at later dates.

While this concern is likely,  the other variants are telling us the time lag between death and infection is usually about 10 to 20 days.  So far,  Omicron has been around for almost 9 weeks or 63 days.  We don't think there will be much change unless Omicron mutates further at a later date into a more vicious variant. 

What to expect for the 2-Dose Vaccinated?

Interestingly,  SAMRC also provided breakdown figures for the vaccinated and unvaccinated for Omicron infection.  

So far,  SA has a vaccination of about 30% which means 1/3 of the population is vaccinated whereas the other 2/3  is unvaccinated.   By using this vaccination ratio,  we could roughly estimate the effectiveness of the vaccines in SA to be about 50% as shown in the following workouts.

The 50% vaccine effectiveness is not enough to keep Omicron at bay.

Again,  the vaccine effectiveness is worked out based on the limited data.  It cannot represent the actual and real result;  however,  it does reflect that the SA vaccine,  which is predominately 2-dose Pfizer,  has lower vaccine effectiveness against Omicron.  These are also the findings of the most recent Pfizer laboratory work.  

What are the Pfizer Laboratory Findings?

Pfizer in its latest press announcement on December 08, 2021, has the following important claims

1)  The Pfizer's booster shot can induce antibodies that can neutralize Omicron to match the level comparable to other variants;

2)  The existing Pfizer 2-Dose may not be able to protect against Omicron.   It has been found to have a 25-fold reduction in the neutralization titers.

What is this 25-fold Reduction?

This is jargon in immunology.  It is a measurement used to indicate the fold-increase or reduction in the levels of neutralization of antibodies.   Here is a pictorial representation of how they work out the 25-fold increase/reduction.

There is a relationship between vaccine effectiveness and fold-reduction but at the present time,  there is no direct conversion available for working out the Covid vaccine effectiveness using the fold level reduction in antibodies.

What to Expect Now?

It has been found that Omicron is a heavily mutated variant.  It has been identified to have 30 changes to its spike protein whereas Delta has only 13 changes.    The scientists to date do not have many clues about how Omicron has acquired so many mutation changes and the speculation is that Omicron appears to be a much vicious variant compared to its predecessors.

The US expert,  Dr. Anthoney Fauci, pointed to the evidence about Omicron being more transmissible but less severe.  But he expected more evidence and data to come before he can reach a definitive conclusion.    Because Omicron is more transmissible,  it has been identified as a candidate "likely to mutate in places where vaccination is low and transmission is high,"    

However,  many experts including those in WHO are keeping track of Omicron closely as they are saying this Omicron could be a 'turning point" of the present pandemic because its behavior is much different from the rest of the variants.   This Professor of Epidemiology,  Prof Ralf Reintjes,  from Hamburg University was of the view that "Omicron could mark a positive turning point in this pandemic".  Let's watch what he was trying to tell us in this video.

Just to recap.  The experts are warning us that this Omicron is very transmissible but at the moment,   it is less severe than the rest of the variants.   However,  we are asked not to be premature optimism & expectation about Omicron.  

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Update: 15 December 2021

Detecting Omicron

The presence of Omicron can be detected using some brands of Antigen Rapid Test (ART) or LFT.  One can also detect Omicron by using PCR tests.  However,  ART or LFT can only tell if one is infected and it cannot tell by which type of virus.   Only the PCR test can tell the difference.    

In the past,  the laboratory will have to do genome sequencing to detect the difference.   This genome sequencing could cost as much as USD1000/= per sample because the detecting agent is quite expensive.   Fortunately,   Omicron shares a testing pattern quite similar to Alpha which has almost extinct and some manufacturers can come up with PCR testing kits that can detect Omicron fairly quickly.   So far,  the following brands have claimed that their PCR testing kits can detect the Omicron variants.

1.  Thermo Fisher Scientific, Abbott, Qiagen, Cue Health and Co-Diagnostics (US)

2.  Roche (Germany)

3.  Acumen (Singapore)

4.  IIT Delhi (India)

FDA said the following PCR test kit will return false-negative results.

Applied DNA Sciences, Meridian Bioscience, and Tide Laboratories 

Update: 23 December 2021

South Africa is presently having the highest proportion (96%) of Omicron patients in the World.  Its National Institute for Communicable Diseases (NICD) has a daily surveillance report published on this website.    It has a network called "DATCOV-Gen" where studies about Covid hospitalization details are often reported.   One of its most recent studies published in  BMJ,  an internationally renowned medical journal, is shown here.  

The study report concluded that those suffering from Omicron are likely to have lower odds of being admitted to hospitals as compared to non-omicron patients.  The odds ratio (AOR) was estimated to be 0.2 @ 95% confidence interval (CI) 0.1-0.3).    In other words,  those suffering from Omicron would have an 80% lesser chance of being admitted to a hospital for treatment.

Update: 29 December 2021

The infection rate in Gauteng,  SA has receded by 75% from 630 new cases per mil to about 120 cases per mil.   The hospitalisation rate came down by about 30% and death rates appear to be muted as shown in this chart worked out by Dr. Ridhwaan Suliman

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