Yes, the new strain is called NB.1.8.1, and it’s a sub-variant of Omicron.
Omicron was the dominant strain in Ireland during late 2021 and throughout 2022.
The NB.1.8.1 strain was first detected in January 2025.
In May 2025, the World Health Organization (WHO) classified the NB.1.8.1 strain of COVID-19 as a “variant under monitoring,” assessing the global public health risk as “low.”
The WHO states that currently approved COVID-19 vaccines are expected to remain effective against symptomatic and severe disease caused by this variant.
“Despite observed increases in cases and hospitalizations in some countries where NB.1.8.1 prevails, current data do not indicate that this variant leads to more severe illness compared to other circulating variants.”
In the week ending May 18, the new strain comprised 13.6% of all cases, an increase from 0.7% in the week ending April 20.
Yes. As of June 9, 2025, there are 19 cases of this variant detected in Ireland. The first case was identified on April 16, 2025.
During the five-week period from April 20 to May 24, the new strain accounted for 13.6% of all sequenced cases – compared to 4.3% in the preceding five weeks.
These figures are based on GISAid sequence data. GISAid is a global science initiative that monitors and provides access to data on influenza viruses.
In response to an inquiry from the , the HSE stated that based on WHO data and the mutation profile, there is no evidence of increased severity or impact on vaccine effectiveness against severe disease.
The HSE added that since the end of March 2025, COVID-19 levels have shown a slow but steady increase. However, “levels of hospitalisations, ICU admissions, and deaths remain low.”
No. Multiple COVID-19 variants are still circulating. In a statement last week, the WHO said that the variants “continue to evolve.”
They stated: “Between January and May 2025, there were shifts in global SARS-CoV-2 variant dynamics. At the beginning of the year, the most prevalent variant tracked by WHO at the global level was XEC, followed by KP.3.1.1.”
“In February, circulation of XEC began to decline while that of LP.8.1 increased, with the latter becoming the most detected variant in mid-March. Since mid-April, the circulation of LP.8.1 has been slightly declining as NB.1.8.1 is increasingly being detected.”
Currently, six variants are being monitored.
Common symptoms are similar to typical Omicron subvariants from the peak of the pandemic in 2021.
These include fatigue, fever, muscle aches, and a sore throat.
Writing in , Australian virologist Lara Herrero noted: “The evidence so far suggests NB.1.8.1 may spread more easily and may partially evade immunity from prior infections or vaccination. These factors could explain its increase in sequencing data.”
“However, importantly, the WHO has not yet observed any evidence that it causes more severe disease compared to other variants.”
The WHO emphasizes that the global public health risk associated with COVID-19 remains high, though there has been evidence of a “decreasing impact on human health” throughout 2023 and 2024.
The HSE advises that anyone experiencing COVID-19 symptoms, even mild ones, should stay home until 48 hours after their symptoms have mostly or fully resolved.
Individuals should also avoid contact with others, particularly those at increased risk of severe COVID-19.
