The coronavirus subvariant surging in Europe is a more-contagious type of Omicron which experts fear could soon take over in the US
Markus Schreiber/AP Photo
- A subvariant of Omicron called BA.2 is driving a new wave of COVID-19 in Europe.
- The variant is also present in the US and experts are concerned it could soon take over.
- Here is what we know about this subvariant.
A subvariant of Omicron called BA.2 is driving a new wave of COVID-19 cases in Europe. Experts warn it could soon become dominant in the US, causing concern of an impending surge.
Here is what we know about BA.2.
BA.2 spreads more quickly than 'normal' Omicron BA.1
The Omicron variant is made up of three genetically distinct sub-variants, BA.1, BA.2, and BA.3.
All of these subvariants are capable of spreading much more quickly than earlier variants like Delta. But BA.2 is thought to spread the quickest.
According to Antony Fauci, the White House Medical advisor BA.2 is 50 to 60% more transmissible than BA.1, though others say it is closer to 30% more transmissible.
BA.2 seems as good as dodging vaccination as other Omicrons
Omicron is thought to dodge immunity from two doses of vaccine much more efficiently than Delta, and early data suggests BA.2 is no exception.
The UK Health Security Agency (UKHSA) found that BA.2 seems just as good at dodging two-shot protection against symptomatic disease as BA.1.
It's not yet clear whether BA.2 evades protection against more severe outcomes — hospitalization and death — more efficiently than other Omicrons.
Experts have encouraged people to get booster shots, which increases the protection against severe outcomes after Omicron infection. Protection against severe outcomes from two doses of vaccine seems to wane much more quickly with Omicron than with Delta.
Two shots reduced the risk of hospitalization from Omicron by only 30% to 35% six months after the second shot, compared to 70% to 85% against Delta, per UKHSA.
A booster increased the protection against hospitalization, reducing the risk of hospitalization by 80% to 95% within three months of the shot, and 75% to 85% four to six months, per UKHSA.
BA.2 is not thought to be more dangerous than BA.1
Omicron seems to gravitate to different parts of the body than Delta, and that's good news. The variant prefers staying in the upper airways of the body, which may be why it causes less severe disease after infection, per early research.
BA.2 is expected to behave in a similar way. Though one preprint on hamsters suggested that the virus could replicate more quickly in upper airways than BA.1, early real-world data from Denmark, South Africa, and the UK suggest BA.2 does not cause more severe disease than BA.1, Medical News Today reported.
But even though a smaller proportion of people infected with BA.2 will be severely ill, the burden on the healthcare system could remain high because the variant causes more cases overall.
BA.1 infection is thought to provide good protection against reinfection by BA.2
There have been some documented cases of people who had caught BA.1 being reinfected by BA.2, but this seems rare.
Infection by BA.1 seems to provide robust protection against BA.2, though it is not clear for how long, the World Health Organization said.
Mild BA.2 COVID-19 will probably feel like a cold
Tim Spector, lead researcher on the Zoe COVID -tracking project, analyzes COVID-19 symptoms daily using an app.
Though he did not specifically refer to BA.2, on March 20 when BA.2 made up most of the cases in the UK, he said the top six COVID-19 symptoms were:
- Runny nose
- Headache
- Fatigue
- Sore throat
- Sneezing
- Persistent cough
from Business Insider https://ift.tt/eaAqFoG
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