A new Irish study aims to determine if babies born during the COVID-19 pandemic are more likely to go on to develop allergies.

Allergic diseases, such as asthma, eczema, hay fever and food allergies have become more common over the last three decades. This is thought to be due to what is known as the 'hygiene hyposthesis'.

People nowadays are less exposed to infections as a result of smaller family sizes, a community focus on hygiene and the introduction of effective immunisations against serious infections.

Scientists at the Royal College of Surgeon's In Ireland's (RCSI) Department of Paediatrics and Children's Health Ireland (CHI) Temple Street want to look into this further.

They aim to investigate whether lower rates of viral infections and improved air quality, which emerged as a result of lockdown, are going to make allergic conditions more or less common in children born into families who have experienced isolation and social distancing.

The scientists emphasised that the identification of non-acute consequences of COVID-19 is now a major priority worldwide.

"The lockdown presents a unique scientific opportunity to examine the early origins of often lifelong diseases, issues that constitute a major health and social burden in Ireland and other developed countries," commented study lead, Prof Jonathan Hourihane, of the RCSI's University of Medicine and Health Sciences.

He explained that after a baby is born, their immune system starts to focus on "all the new challenges that life outside the womb brings, including fighting off infections and responding to immunisations".

"We want to see children playing on the floor, getting dirty, and being exposed to lots of people in lots of environments. The outcome of this is usually a stronger immune system, linked to a healthy population of gut bacteria, called the microbiome," he noted.

Ireland's COVID-19 lockdown appears to have led to a reduction in the amount of other viral infections, which usually circulate in the community.

"We have seen less than half the usual number of attendances at paediatric emergency departments and rates of seasonal influenza and other late spring upper respiratory viruses seemed much lower than usual during this time," Prof Hourihane pointed out.

This new study will involve 1,000 babies born between March and May 2020. The parents of children born during this time in Dublin's Rotunda Hospital and the Coombe Women and Infants University Hospital, will be invited by letter to participate.

The study will involve a small finger prick of blood being taken from the infant at the beginning of the study and one year later to test for each child's COVID-19 antibody status.

Stool samples from each child will also be examined at six months and one year by Prof Liam O'Mahony in the Alimentary Pharmobiotic Centre in UCC. This will be to determine the children's gut bacteria/microbiome profile.

Allergy tests will be performed at one year and two years old to detect if the children have developed markers of allergic conditions.

The scientists highlighted that if allergies are detected, the children involved will get allergy care faster than they would otherwise.