Hello, welcome to my channel Medicine with Dr. Moran. We have a new Greek letter in the
Covid-19 alphabet O for Omicron. The Who has just identified this as a variant of concern.
There's a link below to their website on this topic in the description if you're interested.
The variant is also known as B.1.1.529.
This is the definition of a variant of interest as well as a variant of concern from the WHO.
The first known confirmed infection with Omicron was from a specimen collected
a few weeks ago November 9th in South Africa. Well done to the medical researchers in South Africa
This kind of transparency is excellent if only we saw this at the beginning of the pandemic.
The speed at which they've let everybody know in the world about this particular variant
is so important. It is of course not known where Omicron has truly originated. It was
simply sequenced in South Africa but the patient that it came from or from those who
infected this patient previously could well have come from any other part of the world.
Given the time frame involved it almost certainly is already in many countries if not almost all
countries worldwide although only a few have reported that they found it so far. I think you're
going to see a lot of cases reported in the next few days in many countries throughout the world
and the reason is they're looking for them. Now the chair of the South African Medical
Association, Dr. Angelique Coeteze herself noted a family of four in her practice who presented
with very mild symptoms with profound fatigue sore muscles but no loss of smell or taste.
She contacted south Africa's vaccine advisory committee November 18 concerned
that there might be a new strain here given the different presenting symptoms.
She has stated publicly that she's had about 25 patients in total now who've tested positive for
this variant and about a half of the patients were vaccinated. They were younger people and so
they may have a slightly different presentation. Some patients had a slight cough. Now this lack
of significant pulmonary symptoms could be a good thing as many covet patients ultimately of course
develop respiratory failure which can lead to death and perhaps this particular variant does not
affect the lungs as much. Also the lack of cough means that there should be less transmission.
The lack of problems with smell and taste also is a good thing that means there's less inflammation
in obviously the nose as well as the mouth and that may mean less shedding as well.
That's purely speculative however. We obviously need well done research not anecdotal reports
like this but you have to remember that anecdotal experience though is how we pick things up as you
can see in this case. On the slide the WHO have recommended enhanced surveillance and
sequencing efforts to better understand Omicron. Collaboration with investigators in South Africa
and other countries are needed to look at the genome sequencing of this particular variant and
where it's possible investigations and laboratory evaluations to further understand diagnostic
methods like PCR and antibody testing immune responses of people who acquire this antibody
neutralization transmission and so on. There are individual recommendations which of course
are no different than what we currently have. The good news is that PCR testing is picking up this
variant although of course you need to do genomic sequence once you have a positive test. That way
you know which variant that you're dealing with. Of interest is that PCR testing often takes a
look at three different target genes. One of the target genes which is the S gene and a number of
labs have indicated that this S gene test can be negative while the others are positive. So this
particular test might be a marker for the variant. Of course this is pending sequencing confirmation.
Now why is this variant concerning? Well there's three main reasons. Firstly there's the potential
for increased transmissibility, secondly there are large numbers of mutations here over 30,
and thirdly there's potential for the variant to evade natural immunity and vaccinated immunity.
First in terms of transmissibility the WHO reports in South Africa the number of cases
of this variant does appear to be increasing in many provinces in their country. We don't yet know
whether this will be more transmissible or less than other variants. Research on transmissibility
remains to be seen. In general when there are more mutations in a virus it often mutates to
become more transmissible. This is obviously not always the case. We did see Delta become
much more transmissible although it was not more virulent in other words delta did not cause more
severe disease than the other strains. Viruses can often mutate themselves out of existence
by becoming less and less effective and even less and less transmissible.
The second point is that the number of mutations that Omicron has in its spike protein is
certainly impressive at over 30. There are 34 mutations specifically that have been reported.
Remember the spike protein is what's used by the virus to attach itself to the human cell
through the Ace2 receptor. There's about a hundred different epitopes across the whole
of the spike protein and B cells which make antibodies make antibodies for many
different parts of the spike protein not just a single antibody against the whole protein.
So some of the antibodies made against parts of the spike protein will still have some efficacy.
Now the T cells that we have line up across these hundred epitopes which make up the spike protein
and obviously the vast majority are the same for this variant compared to the other variants.
T cells have a lot to do with why people get severe disease and the memory T cells are still
going to recognize the vast majority of the spike protein epitopes as foreign. Ultimately we need
good medical research to know how people are going to respond when they do get infected with Omicron.
Now there's four groups of people that are relevant when you think about it.
There are those that have no immunity meaning they've never been infected or vaccinated,
those that have natural infection but no vaccination, those that have been vaccinated
without natural infection, and lastly those that have had natural infection and vaccination.
Seeing what kind of infections each group gets will be important to further our understanding.
If infections with this variant are quite mild as the chair of the South African Medical Association
has found we will all be reassured. This of course is ultimately our goal it's to turn
this endemic virus into a virus that causes common cold symptoms that we can all manage at home. Now
the third point is whether this particular variant could evade natural and vaccinated immunity. It'll
probably take two or three weeks for neutralizing antibody tests to be done against this variant.
If it's relatively easily neutralized with the antibodies and people who have been naturally
infected or vaccinated then there won't be any need to change the current vaccines. If it's not
easily neutralized then the vaccines will need to be reformulated against this particular variant. I
make note that this can be done relatively quickly if you look at the MRNA vaccines. We know this
could probably take place in two to three months. Production obviously would have to be ramped up.
Now clinical research in terms of patient outcomes of who actually gets this strain will need to be
done to see whether it's more virulent or less virulent than with the strains we've had so far.
Now ultimately this all speaks to the issue of vaccine equity. I've mentioned this in many of my
videos because until people around the world have immunity there's going to be large-scale ongoing
viral replication in millions of people which will ultimately lead to variants like this one. There
are many people in the western world who have had three vaccinations yet there are health care
workers and other people around the world at risk who have not even received a single vaccination.
Thank you for listening to my presentation today on Omicron.
I'm Dr Keith Moran. Get healthy and stay healthy.