Two further cases of the BA.4 Covid variant of concern have been recorded in Ireland.
Fears have risen that the more transmissible strain is now building momentum in the country after two previous cases were reported by Chief Medical Officer Dr Tony Holohan earlier this month.
Although so far, only four cases have been detected, experts believe BA.4 and BA.5 will eventually become the dominant strain in Ireland, with the virus likely to have spread to higher numbers of people already without detection.
READ MORE: Fears fifth wave of Covid on the way for Ireland as first case of new variant of concern identified
The variant is part of the Omicron family, but it is thought to be less severe, meaning those who are vaccinated face a lower risk of getting seriously ill.
The World Health Organisation ’s infectious disease epidemiologist, Dr Maria Van Kerkhove, confirmed that the WHO had officially classified the new strains as variants of concern, prompting fears of a new wave as cases are predicted to spike in the coming weeks.
She said: “What we don’t have yet is information about the change of severity with these new sub lineages BA.4 and BA.5.”
The news comes less than two months after Prof Luke O’Neill warned that Omicron mutation BA.2 is 30% more infectious than Omicron and would “sweep up everyone who didn’t get Omicron”.
But epidemiologist Dr Van Kerkhove added that the new Omicron strains BA.4 and BA.5 are even more transmissible than BA.2, the dominant strain of Covid-19 in Ireland and globally.
She explained: “We know that BA.4 and BA.5 have growth advantages – it is more easily transmissible.
“This highlights the importance of surveillance and sequencing.”
Dr Van Kerkhove said there could be more Omicron mutations in the future “as the virus evolves” and said the force of potential new waves in countries like Ireland, which had large Omicron BA.2 waves, remained unknown.
She said: “We still need to monitor this virus very carefully because it still evolves. We don’t have certainty as to how it will evolve.”
The new strains were first discovered in South Africa at the beginning of this year and since have become dominant there.
BA.4 was first detected in South Africa and is now spreading in 20 heavily vaccinated countries worldwide, while BA.5 has been found in 19 countries.
The UK has also reported an increase in cases of the new variants with 115 cases of BA.4 and 80 cases of BA.5.
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