As more highly-transmissible Omicron variants gain traction in Ireland, two more cases of a new Covid-19 variant of consideration were identified.
Speaking on the matter, chief medical officer Dr. Tony Holohan said four incidents of BA.4, a sublineage of Omicron, were discovered, rising from two a week ago.
According to his most recent weekly pandemic report, no cases of a similar variant, BA.5, have been recognized.
According to Dr. Holohan, 23 cases of another Omicron variation, BA.2.12.1, have been identified in Ireland. BA.2.12.1 is now responsible for half of all infections in the United States and is blamed for a fresh wave of infections there.
Dr. Holohan said cases in the United States have increased by 33% week-on-week, while hospitalizations have increased by 19%.
BA.2.12.1 is estimated to be about 25% more communicable than the dominant BA.2 Omicron subvariant in Ireland. BA.2 was 50% more infective than the original Omicron variant, resulting in an increase in cases as it dispersed here in the spring.
The European Centre for Disease Control assigned BA.4 and BA.5 as variants of concern earlier this month. They were discovered first in South Africa in January and February of this year and have since become the dominant strain there.
By mid-May, BA.4 and BA.5 had made up 89% and 7% of cases sequenced in South Africa, which had seen a moderate increase in Covid-19 hospital admission. BA.5 now accounts for two-thirds of all cases in Portugal. In the United Kingdom, 80 cases of BA.5 and 115 cases of BA.4 have been identified.
Evasion of Immunity
According to Dr. Holohan, the two strains have a significant growth edge probably because they can circumvent the immune reactions offered by previous infection and vaccination, which weakens over time.
Scientists believe that BA.5 and BA.4 will likely overtake the currently dominant BA.2 sublineage.
There is no evidence that they are far more serious than earlier Omicron lineages. They may trigger the serious spread of the virus in Europe in the coming months, the ECDC cautions.
According to Dr. Holohan’s May 20th document, the cumulative epidemiological situation in Ireland is still “generally positive,” though “we will have to constantly monitor progress with evolving variants in the coming weeks.”
“Although infection levels remain high and a considerable number of cases are getting broad hospital care, the number of confirmed infections and hospitalized patients has decreased significantly in recent weeks.” ICU admissions are also down.
He notes that the health system is still under significant pressure, with few accessible beds and Covid-19 continuing to affect capacity and process efficiency in some regions.
According to Dr. Holohan, a large percentage of younger people have not gotten a booster vaccine against Covid-19; 52% of 16-24 year-olds, 43% of 25-34 year-olds, and 37% of 35-44 year-olds have failed to receive the first booster.
In the meantime, more than 70% of those over the age of 65 have yet to receive a second booster.
“It is critical that these qualified clusters are urged to receive booster vaccination in order to provide optimal protection against the risk of serious disease, as well as other prospective long-term repercussions of infection,” he asserts.