Doctor Mike Hansen - BA.2.75 'Centaurus' - The New Covid Variant of Concern - Covid Variant Update

BA.2.75 aka Centaurus is spreading quickly, mostly in India right now, but has been found in at least 10 other countries, including the US. Right now, the most dominant strain is BA.5. But lets rewind a little bit to understand these subvariants of omicron.
Omicron BA.1 variant emerged this past winter with major genetic differences. BA.1 was quickly followed by BA.2. BA.1 and BA.2 comprised most of the cases this past winter and early spring, with around 1 million cases per day in the US. BA.4 and BA.5, which are very similar, derive from BA.2, as does BA.2.75, although independently.

There is no relation between Omicron BA.1 and the other major variants, meaning no relation to Alpha, Beta, Gamma, Delta. BA.4 and BA.5 are more than capable of reinfected those with previous covid infections, including those who’ve had omicron. That’s regardless of vaccination status as well.

Just like those infected with omicron BA.1 were susceptible to BA.2, and so on. This report indicated that BA.5 was about15-fold more resistant to the monoclonal antibody treatent Evusheld and Sotrovimab compared with previous variants.

This resistance, in addition to new mutations, is likely related to sensitivity to a membrane protease, TMPRSS2, that is associated with cell membrane infectivity.

BA.5 has a greater sensitivity to TMPRSS2 inhibitor Nafamostat, meaning that BA.5 could be more similar to the Delta variant of 2021. Especially when you consider that BA5 is getting into the lungs on a more frequent basis, compared to omicron.

But what about the newest subvariant of omicron, BA.2.75? On July 7th the WHO classified it as a variant-of-concern, and its being monitored closely. It has a specific group of mutations in its spike protein, in addition to those found in BA.2, BA.4, BA.5, and other mutations outside the Spike protein?

The Spike is the most heavily mutated protein in the Omicron family.

There are 36 mutations in the spike protein of BA.2.75.

To put that in perspective, some variants like alpha didn’t even have that any in its entire genome. The unique mutations of the BA.2.75 Spike protein are located in 2 regions: the RBDomains, and the N-terminal.

The receptor-binding domains (RBD) are the typical targets for neutralizing antibodies. Neutralizing antibodes that come from either vaccine immunity, immunity from previous infection, or in the form of monoclonal antibody treatment.

So when you have mutations in this location, that means there is a higher probability that those antibodies will be useless.

In this study, they generated pseudoviruses that harbored the spike proteins of BA.2.75, BA.4/5 and BA.2 and evaluated the effectiveness of ten different monoclonal antibodies treatments on them.

In this pre-print study, but based on these preliminary findings, the authors concluded that 3 of the monoclonal antibody treatments (regdanvimab, sotrovimab, and tixagevimab) unfortunately did not exhibit antiviral effects against BA.2 and BA.4/5. But the good news is that it did so against BA.2.75, which suggests that these antibodies can be used for the treatment and prevention of BA.2.75 infection.

But the spike protein mutations, its not just about escaping antibodies. Its also allows it to be more transmissible, when those mutations promote better binding to the ACE2 protein on our cells.

And because of this, and because of the antibody escape, it continues to be a cat and mouse game between our immune system, and new covid variants that keep mutating, that keep evolving.

And that’s why it’s a continuous back and forth of adapting new vaccines that fight these new variants, like the new bivalent vaccine that is expected to battle BA.4, BA.5, and BA.2.75, likely being made available in the fall or winter. In addition to BA.2.75, recent reports from India suggest that there are associated lineages BA.2.74 and BA.2.76 that are also circulating right now. So there’s more to come with these variants, so we’ll see.
But the bottom line? Covid isn’t going anywhere. And with BA4, BA5, and now BA2.75, circulating in high numbers, the risk of getting infected, or re-infected, remains high.

#covid #omicron #omicronvariant

[dianelengyel]

People think I'm over reacting wearing a mask in public spaces but I'm diabetic with high blood pressure. People Need to remember that some of us are More Vulnerable to Hospitalizations and Severe Illness. Do Not Judge Others

[whitelabrat]

I have a background in public health and I just wanted to let you know how remarkably effective you are at communicating information.

You include enough detail to make your point without over whelming people and your data is quite solid. I know you may think this is just basic to being a public health educator and you would be mistaken. Many people are great with data and have a hard time turning it into effective communication.

Well done.

[joesauer]

This pandemic is like a bad dream that you can't wake up from. 😫

[merian_d]

I got covid Sunday, about 2 days ago. It started with a headache and sore throat. Mind you, I am fully vaccinated, boosted, and had covid already about 2 years ago. This is probably what I have now. It’s definitely enough to knock me out that I sleep all day, severe nasal and chest congestion, muscle and bone pain, cough, and sore throat that feels like a strep throat. My eyes are always watering because of the fever that comes on and off. Yesterday, my thermometer just said “Hi” 😂 I am keeping an eye on my symptoms and taking meds every 4 hours, but so far, no shortness of breath like the first one. Just feels like a worse flu in winter but in summer 😅

[nicolacoke]

Reports, diagrams, graphs, visuals and the studies, especially your theories are very helpful in understanding 👍

[LaMichiganR]

*GEEZ, that is a lot going on with these strains.* *Thanks for the update.* *Those around me have given up on COVID, but not my family.* *None of us have gotten COVID yet and we try to be as cautious as possible to never get it.*

[jimeagle]

Hopefully this pandemic will teach people they need to be much more proactive in their health and focus on preventative measures (exercise, diet, activity, Sunshine/Vitamin D, healthy weight, etc) ….instead of just relying on swallowing pills and taking boosters.
Thanks
~Jim Eagle

[wmichaelh]

Hi, Dr. Mike - My aunt who was a nurse for many years gave the whole family a remedy for sore throat which is to mix four drops of iodine in 8 oz of salt water. I've used it for years and always helps or totally eliminates the sore throat. I gargle and swab. Nobody listens to me on this stuff but I figure if they want to suffer with a painful sore throat, okay. It's their choice.

[snowps]

Getting over covid this week. That is one tough illness. Didn't feel like I was dying, but covid grips you like an iron fist. It is tough.

[redhammer]

Woke up 2 days ago with a raging sore throat and intense headache. Gargled warm/hot salt water for two minutes then repeated that twice during the day. Late afternoon started sneezing little bit of congestion. Gargled again before bed expecting to be unwell yesterday not so, completely normal. I'm 65+ not vaccinated.

[rogerhargreaves]

I’m glad you have recovered. I had Covid 19 back in 2019 before people knew what it was, even I didn’t know why I was sick at the time. I haven’t had it since because I use common sense. Keep safe peeps.

[salsanchez]

Excellent presentation! Thank you, Dr Hansen!

[aalegalfocus]

Thanks for this timely information. People around me are going to indoor sports events, vacations & cruises, posting pics on social media & then oops, they come down with covid. I'm still masking & trying to avoid indoor activities. Appreciate all the helpful medical information here.

[lilys]

Still in hopes of never having it, I know for many they get through it fine, the as yet unknown long term effects and damage. That is what I am hoping to avoid.

[Sokobansolver]

So now we're moving onto constellations for variant names? When we run out of constellations, then what? Galaxies? Stars? Pokemon? Does this mean we're not getting the highly anticipated Omega variant?

[fundamental]

As always, thank you Dr. Mike. Though I am a retired epidemiologist, I still feel like after all my boosters I need to hide at 70 yrs old. Ugh!

[ApesAmongUs]

"It's a cat and mouse game..." Isn't that standard for corona viruses? I mean, that's why we don't have a vaccine for the common cold (which is caused by a corona virus about half the time)?

[selinachan]

Love your reports and diagrams they are so helpful in explaining covid!

[Novastar.SaberCombat]

Let's just HOPE that the viral mutations stick to their previous patterns: 50% "weaker" but 200% more transmissible. That is EXPECTED.

What would be UNexpected amounts to if the virus became MORE deadly. 😕 As in HIGHER morbidity and hospitalizations.

If that occurs, TBH, society may truly be in big, big, BIG trouble. 😓

[Linda-otpj]

Take good care ALL. THIS VIRUS ISNT GOING AWAY ANY TIME SOON LOVE ONE ANOTHER AND MAKE YOUR OWN GARDEN OF LIFE STAY SAFE STAY WELL