A new variant is likely to soon take over from Omicron as the dominant strain of Covid-19 in Ireland.
The latest variant, BA.2, is described as a "sibling" of Omicron, BA.1, as the pair share a number of similarities.
Leading immunologist Professor Luke O'Neill says scientists are monitoring the new strain "closely" although there is reason for optimism that vaccines will offer strong protection.
It comes as the World Health Organisation met this week and reiterated that BA.2 "should continue to be considered a variant of concern and that it should remain classified as Omicron".
The WHO said: "BA.2 differs from BA.1 in its genetic sequence, including some amino acid differences in the spike protein and other proteins.
"Studies have shown that BA.2 has a growth advantage over BA.1. Studies are ongoing to understand the reasons for this growth advantage, but initial data suggest that BA.2 appears inherently more transmissible than BA.1, which currently remains the most common Omicron sublineage reported."
Prof O'Neill explained what we know about the latest strain so far.
“It’s like Omicron, basically - it’s a sibling of Omicron. They’ve renamed Omicron BA.1 because of the similarities between the two," he told The Pat Kenny Show on Newstalk.
“Overall, so far it doesn’t seem to be that troublesome in that it’s similar to Omicron in how it causes the disease. But the prediction is it will be the dominant one.
“It’s quite different [to Omicron]... there was a slight concern that maybe it would have changed enough to make it more dangerous.
“So far what they’ve found - thankfully - in Denmark, the UK and South Africa [is that it's] causing the same level of disease as Omicron.
“But they’re watching closely. Certainly in unvaccinated people it would be a concern - maybe it would cause more severe disease, for example.
"It’s also more transmissible than Omicron… and Omicron itself was already highly transmissible.”
He added that studies which show that vaccines were "slightly less powerful" against BA.2 shouldn't be cause for major concern.
“It’s kind of a mixed picture. Antibodies seem to be less against BA.2. But the other thing is they’re saying the t-cell part of the immune response seems to be holding up," the Trinity professor said.
“That’s important because there will be more variants down the track. The fact we can still handle BA.2 gives us optimism that whatever variant comes up we should have some immunity against it.”
