Saudi Press

Saudi Arabia and the world
Sunday, Jun 01, 2025

Omicron BA.2: What we know about the Covid sub-variant

Omicron BA.2: What we know about the Covid sub-variant

The highly transmissible Omicron variant now accounts for half of the world's infections.

But Omicron is an umbrella term for several closely related lineages of the SARS-CoV-2 coronavirus, the most common of which is the BA.1 lineage.

Now more countries, particularly in Asia and Europe, are reporting an increase in cases driven by BA.2.

While BA.2 appears to be more transmissible than previous variants, there is no data yet to suggest that it is any more severe.

So how worried should we be about this emerging variant? Here is what we know about it.

What is BA.2?


As viruses mutate into new variants, they sometimes split or branch off into sub-lineages. The Delta variant, for example, comprises 200 different sub-variants.

The same happened with Omicron, which includes the lineages BA.1, BA.2, BA.3 and B.1.1.529.

BA.1 accounts for most of the cases. According to the World Health Organization (WHO), nearly 99% of viral DNA submitted to the global GISAID database as of 25 January were identified as this sub-variant.

BA.2 was first detected in the Philippines


While BA.1 and BA.2 are similar, they are 20 mutations apart.

It is not clear where BA.2 originated, but it was first detected in the Philippines in November.

Where is BA.2 spreading?


The sub-variant of Omicron has been detected in 57 countries now, the WHO says. In some countries, BA.2 accounts for more than half of sequenced Omicron cases, it adds.

In some places, growth in recorded cases of the sub-variant has been sharp.

According to Denmark's Statens Serum Institut (SSI), BA.2 infections rose to account for about half of the country's reported Covid cases in January.

India is another country where BA.2 is rapidly replacing the Delta and Omicron BA.1 variant, according to molecular biologist Bijaya Dhakal.

It is already the dominant variant in several states and likely drove the country's recent third wave of infections.


The Philippines' Department of Health (DOH) said the BA.2 sub-lineage was already prevalent in samples it received at the end of January.

And in England, more than 1,000 confirmed cases of BA.2 have been identified, according to the UK Health Security Agency (UKHSA). It has been designated a "variant under investigation" by British health authorities, meaning they are keeping a close watch on it, but are not overly concerned by it.

BA.2 infections in Germany are also growing faster than BA.1 and Delta, according to Dr Meera Chand, Covid-19 director at the UKHSA.

Is BA.2 more transmissible?


A study of 8,500 households and 18,000 individuals conducted by Denmark's SSI found that BA.2 was "substantially" more transmissible than BA.1.

The study also showed evidence to suggest that the BA.2 sub-variant is better able to evade vaccines.

About half on new cases in Denmark are caused by BA.2


However, vaccinated people are still less likely to get infected than unvaccinated individuals, and they are also less likely to pass it on.

A separate UK study also found higher transmissibility for BA.2 compared to BA.1.

But the preliminary assessment found no evidence that vaccines would be any less effective against symptomatic disease for either sub-variant.

Is BA.2 more dangerous?


There is no data to suggest that BA.2 leads to more severe disease than previous Omicron sub-variants.

"Looking at other countries where BA.2 is now overtaking, we're not seeing any higher bumps in hospitalisation than expected," the WHO's Dr Boris Pavlin says.

Francois Balloux, Professor of Computational Systems Biology and director of the UCL Genetics Institute, said that BA.1 and BA.2 "can be considered as two epidemiologically largely equivalent sub-lineages of Omicron".

As with previous variants, experts believe vaccines will continue to be highly effective against severe illness, hospitalisation, and death.

Dr Chand said: "So far, there is insufficient evidence to determine whether BA.2 causes more severe illness than Omicron BA.1.

"We must remain vigilant and take up vaccinations. We should all continue to test regularly with LFDs [lateral flow devices] and take a PCR [polymerase chain reaction] test if symptoms develop."


No cause for alarm at this stage


Scientists in the UK and abroad are closely monitoring BA.2, a sub-variant of Omicron.

At the moment there is much that is not yet clear.

It appears to have a growth advantage compared to the version of Omicron, BA.1, that has swept the globe. Analysis by the UKHSA suggests it could be substantial, although there is a risk of over-estimating growth advantage in the early stages.

What we know is that it is certainly growing as a proportion of overall cases in the UK.

Because of a quirk in how it shows up in test results, we can see the numbers of suspected BA.2 doubled in the week up to 24 January.

But at that point the sub-variant still appeared to account for less than one in 20 cases.

That contrasts to Denmark, where it has become dominant.

A preliminary assessment by UKHSA did not find a difference in vaccine effectiveness, although it said there was no data yet available on severity.

But it is worth noting that Denmark has seen similar trends in terms of hospital admissions and intensive care as the UK has, suggesting BA.2 does not mark a sea-change in severity.

And even if it does become the dominant version of Omicron, it may not actually alter the trajectory of the pandemic in countries that have seen a big wave of BA.1. That's because there could be cross-immunity - an infection with BA.1 could offer some protection against BA.2.

It is one for the scientists to watch, rather than for the public to be alarmed about at this stage.

Newsletter

Related Articles

Saudi Press
0:00
0:00
Close
OPEC+ Agrees to Increase Oil Output for Third Consecutive Month
Turkey Detains Istanbul Officials Amid Anti-Corruption Crackdown
Meta and Anduril Collaborate on AI-Driven Military Augmented Reality Systems
EU Central Bank Pushes to Replace US Dollar with Euro as World’s Main Currency
European and Arab Ministers Convene in Madrid to Address Gaza Conflict
U.S. Health Secretary Ends Select COVID-19 Vaccine Recommendations
Trump Warns Putin Is 'Playing with Fire' Amid Escalating Ukraine Conflict
India and Pakistan Engage Trump-Linked Lobbyists to Influence U.S. Policy
U.S. Halts New Student Visa Interviews Amid Enhanced Security Measures
Trump Administration Cancels $100 Million in Federal Contracts with Harvard
SpaceX Starship Test Flight Ends in Failure, Mars Mission Timeline Uncertain
King Charles Affirms Canadian Sovereignty Amid U.S. Statehood Pressure
Iranian Revolutionary Guard Founder Warns Against Trusting Regime in Nuclear Talks
UAE Offers Free ChatGPT Plus Subscriptions to Citizens
Lebanon Initiates Plan to Disarm Palestinian Factions
Iran and U.S. Make Limited Progress in Nuclear Talks
The Daily Debate: The Fall of the Dollar — Strategic Reset or Economic Self-Destruction?
Trump Administration's Tariff Policies and Dollar Strategy Spark Global Economic Debate
OpenAI Acquires Jony Ive’s Startup for $6.5 Billion to Build a Revolutionary “Third Core Device”
Turkey Weighs Citizens in Public as Erdoğan Launches National Slimming Campaign
Saudi-Spanish Business Forum Commences in Riyadh
Saudi Arabia and Spain Sign MoU to Boost SME Sectors
UK Suspends Trade Talks with Israel Amid Gaza Offensive
Iran and U.S. Set for Fifth Round of Nuclear Talks Amid Rising Tensions
Russia Expands Military Presence Near Finland Amid Rising Tensions
Indian Scholar Arrested in Crackdown Over Pakistan Conflict Commentary
Israel Eases Gaza Blockade Amid Internal Dispute Over Military Strategy
President Biden’s announcement of advanced prostate cancer sparked public sympathy—but behind closed doors, Democrats are in panic
A Chinese company made solar tiles that look way nicer than regular panels!
Indian jet shootdown: the all-robot legion behind China’s PL-15E missiles
The Chinese Dragon: The True Winner in the India-Pakistan Clash
Australia's Venomous Creatures Contribute to Life-Saving Antivenom Programme
The Spanish Were Right: Long Working Hours Harm Brain Function
Did Former FBI Director Call for Violence Against Trump? Instagram Post Sparks Uproar
US and UAE Partner to Develop Massive AI Data Center Complex
Apple's $95 Million Siri Settlement: Eligible Users Have Until July 2 to File Claims
US and UAE Reach Preliminary Agreement on Nvidia AI Chip Imports
President Trump and Elon Musk Welcomed by Emir of Qatar Sheikh Tamim with Cybertruck Convoy
Strong Warning Issued: Do Not Use General Chatbots for Medical, Legal, or Educational Guidance
Saudi Arabia Emerges as Global Tech Magnet with U.S. Backing and Trump’s Visit
This was President's departure from Saudi Arabia. The Crown Prince personally escorted him back to the airport.
NVIDIA and Saudi Arabia Launch Strategic Partnership to Establish AI Centers
Trump Meets Syrian President Ahmad al-Shara in Historic Encounter
Trump takes a blow torch to the neocons and interventionists while speaking to the Saudis
US and Saudi Arabia Sign Landmark Agreements Across Multiple Sectors
Why Saudi Arabia Rolled Out a Purple Carpet for Donald Trump Instead of Red
Elon Musk Joins Trump Meeting in Saudi Arabia
Trump says it would be 'stupid' not to accept gift of Qatari plane
Quantum Computing Threatens Bitcoin Security
Michael Jordan to Serve as Analyst for NBA Games
×