Principal Brian Guthrie of Ebrington Primary School noted that some pupils needed hospital treatment and classroom assistants were also absent, disrupting lessons and causing gaps in literacy and numeracy teaching.

The school reports a spike in illness, likened to the Covid era by the headteacher, as 170 pupils were off sick in one day.

The NHS issued a flu vaccination SOS to tackle the outbreak, highlighting that vaccines are free for eligible groups in Northern Ireland and available through GPs, pharmacies, school programs, and local clinics.

In Northern Ireland, flu vaccines are free for children aged 2 to 16 and for high-risk groups and health workers; other adults can pay or access vaccines via GP clinics, pharmacies, or school programs.

Health authorities warn this flu season could be the worst in a decade, with the week ending late November showing the highest flu activity in under-fives and high positivity among 5- to 14-year-olds (54.2%).

Pharmacists report higher demand for vaccines and occasional quota shortages, with protection typically developing seven to ten days after vaccination.

In the past two weeks, confirmed flu cases in Northern Ireland more than tripled, rising from 273 to 954, with officials expecting further increases.

The flu and other infections surge is part of a broader rise across Northern Ireland, with both adult and child flu cases increasing more than threefold over two weeks.

Vaccination uptake among children remains below 50% across all age groups, with preschoolers at 25.8%, primary at 44.7%, and post-primary at 30.3%; officials aim for higher uptake (85-90%).

Despite vaccination efforts, child uptake stays under 50%, and about 40 schools had not yet been visited by the vaccine programme.

Public Health Agency data indicate vaccination reduces hospital admission risk by about 70%, and around 1,200 schools are eligible for school-based flu vaccination, though about 40 had not yet been visited as of the report.

Experts attribute the surge to a mutated seasonal flu strain (H3N2), which is more infectious and appears to affect children more significantly this year.

Staff absences, including classroom assistants, worsened learning disruption and blocked literacy and numeracy teaching, particularly affecting younger pupils early in the week and older students later on.

A Northern Ireland primary school principal described the week as worse than Covid times after 170 pupils were off sick in a single day, with some requiring hospital treatment and others admitted for care.