What is the Omicron BA.2 covid-19 variant? How contagious is the variant?
More information to understand the new Omicron subvariant has been ascertained and it spreads faster than its BA.1 cousin.


Despite the global dominance of the original Omicron variant, BA.1, another pothole in the covid-19 highway has appeared, BA.2. The cousin of the former, BA.2 has begun to take a hold in countries around Europe, especially Denmark. Scientists have begun to test the new subvariant to assess its dangers, and have returned important findings.
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- Denmark declares end to the pandemic
What are the differences in the two variants?
Like with Omicron BA.1, the subvariant is extremely transmissible. However, BA.2 is a step above that, with estimates by the Danish health authorities that it is a further 50 percent more transmissible than BA.1.
The omicron BA.1 variant is more transmissible than the delta variant. BA.2 probably takes the basic reproduction number up to at least 12 - well and truly measles territory.
— Dr Zoë Hyde (@DrZoeHyde) January 31, 2022
SARS-CoV-2 is now >4 times more transmissible than it was in early 2020. https://t.co/ireLQ9FGdp
This transmissibility has got some scientists worried, but some good news about the variant is that in many other respects it is similar to the original Omicron variant.
This is because preliminary evidence suggests there is no greater risk of fatality between the two cousin variants, just the transmissibility. As long as hospitals remain with enough capacity to treat the seriously ill, then the new subvariant poses no more risk to the population.
Furthermore, while extensive testing has yet to be completed, scientists believe Omicron BA.2 is treatable with current vaccines, just like Omicron BA.1.
Latest 3-shot vaccine effectiveness data vs omicron, summarized
— Eric Topol (@EricTopol) January 31, 2022
✓ ~50% against infections
✓ ~90% against hospitalizations
✓ ~95% against deaths https://t.co/mr5Rp7lcJI
“So far, evidence from our colleagues in Denmark show that while it could spread faster, there is no evidence of increased severity,” said Prof Seshadri Vasan, a covid-19 vaccine researcher from Australia’s Science Agency, “Therefore it is important to keep calm and continue existing measures such as getting ourselves the vaccinated, including the booster dose, and following social distancing, masks and local guidelines.”
This should give some hope that the end of the pandemic is approaching. Despite the growing number of BA.2 cases in the country, Denmark is continuing with its lifting of all restrictions, effective Tuesday February 1.