The public health strategy during the SARS‐CoV‐2 (COVID‐19) pandemic of 2020–2021 led to profound changes in social behaviour, affecting not only familial but also wider social interactions. These changes may have altered viral and bacterial interchange.A significantly decreased diversity of gut and skin microbiota has been demonstrated in allergic individuals compared with non‐allergic subjects.
The CORAL study is a longitudinal study of the impact of the coronavirus pandemic on allergic and autoimmune dysregulation of infants born from March to May 2020, during Ireland's first lockdown (Ireland formally entered national lockdown on 27 March 2020, although severe restrictions had been gradually escalated for the 2 weeks prior to that date. The first release of lockdown was on 8 June 2020). CORAL will follow the cohort initially until the children are 2 years old, with stool sampling at 6, 12 and 24 months for microbiome diversity analysis and allergy testing and blood RNA and epigenomic testing at 12 and 24 months.Now, in the immunization phase of the pandemic response, attention is shifting from immediate population protection to the consequences of both the pandemic and the societal disruption created by lockdown. There are particular concerns that important medical care (such as infant immunizations) may have been delayed, or even refused, due to patient or family concerns about infection risk when attending healthcare facilities also managing COVID‐19.
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,We report here the impact of COVID‐19 lockdown on feeding practices, healthcare access, completion of immunization and COVID‐19 infection rates in Irish babies to 6 months of age enrolled in the CORAL study.Ethical approval was obtained from the National Research Ethics Committee (20‐NREC‐COV‐067) and the participating hospitals' ethics committees. Informed written parental consent was obtained.There were 3773 infants born in the 2 participating major maternity hospitals in Dublin in March, April and May 2020. Invitations were sent to the families of 3065 term babies who were eligible for inclusion. Exclusion criteria were pre‐birth PCR‐proven SARS‐CoV‐2 infection in a parent or co‐dwelling person, intravenous antibiotics in the neonatal period, multiple births or major congenital anomaly.At 6 months (September‐November 2020), families were sent a questionnaire and a stool sample collected for microbiome analysis (results will be reported elsewhere). Families were also offered point‐of‐care SARS‐CoV‐2 antibody testing (VivaDiag™ SARS‐CoV‐2 IgM/IgG Rapid Test) for the infants. However, an escalation of national travel restrictions in response to the second surge of COVID‐19 in September and October 2020 restricted access to this testing for some infants.A total of 365 infants were enrolled. One hundred and ninety‐five babies (53.4%) were male, 94.5% were of “White Irish” or “Any Other White” background, and 94% of mothers were educated to third level or higher. The average birthweight was 3.5 kg. Most babies were either firstborn (45%) or secondborn (37%). In infants with siblings (n = 201), atopic dermatitis was the most common allergic condition reported in siblings (15.4%), followed by asthma (12.4%) and food allergy (11.4%). Allergic rhinitis was the most commonly reported atopic condition in both mothers (36%) and fathers (30%).A total of 360 6‐month questionnaires were returned. Exclusive breastfeeding rate at 6 months was 38%; a further 15% were receiving both breastmilk and infant formula. 92% were having regular solid foods with a median weaning age of 5 months (range 3–6 months). The rates of introduction of allergenic foods such as egg and peanut are outlined in Table 1.
TABLE 1
Introduction of allergenic foods at 6 months
Allergenic foods at 6 months
Introduced food (%) Total N = 360
Egg
95 (26%)
Peanut
49 (13.6%)
Tree nut
12 (3.3%)
Wheat
151 (42%)
Fish
59 (16.4%)
Dairy
166 (46%)
Dairy alternatives
17 (4.7%)
Introduction of allergenic foods at 6 months99% of infants had attended their general practitioner for scheduled immunizations at 2, 4 and 6 months of age,
and 7.5% of babies had been admitted to hospital in the first 6 months. Antibiotics had been prescribed for 25 infants (7%) and 5 of those infants had received more than one course. Possible allergic reactions to a food or environmental substance were reported by 47 children (13%), but on elaboration most described a flare of eczema without identifying a particular allergen.By the age of 6 months, 30 (8.3%) had had community testing for SARS‐CoV‐2 PCR due to symptoms or known close contact, and 2 (0.5%) were PCR‐positive. One of these 2 babies attended the 6‐month review; the other was unable to attend due to national travel restrictions. A total of 268 (73%) of babies had point‐of‐care lateral flow immunoassay testing at 6 months as part of the study, of whom 3(1.1%) returned positive results for IgM and IgG SARS‐CoV‐2 antibodies. One infant (as above) had known prior PCR‐proven SARS‐CoV‐2 infection but there were two further cases with no known COVID‐19 exposure. Of these, 1 was PCR‐positive (indicating very recent or current infection) and the other was PCR‐negative (indicating remote infection). Overall, 4 babies (1%) were shown to have immunological evidence of exposure to SARS‐CoV‐2 infection before the age of 6 months.It is reassuring that this population of infants born during lockdown had been presented as advised for routine health care such as immunizations, actually at even higher rates than national norms. Weaning rates were in line with national trends in Ireland, and despite the low rates of egg and peanut introduction, these are in line with national data, so weaning to allergenic foods did not seem to have been impacted by heightened fear of adverse outcomes or risk of needing to emergency care during the pandemic. In contrast, the overall rate of attendance at hospital for any reason (7.5%) or any use of antibiotics were lower than expected, supporting our previous data about significant changes in circulation of virus‐related illnesses in the early stages of the 2020 lockdown.This self‐selected cohort of infants is largely representative of the overall Irish population.
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The proportion of firstborns (45%) is higher than the national average (38.8%) but these larger maternity hospitals (more than 8000 deliveries each per annum) have high rates of primigravida patients.
A notable difference is the level of maternal education. In the 2016 Irish census, 43.2% of women were educated to third level compared with 94% of mothers in this study.
This, along with mothers working from home during lockdown, is likely contributing to the atypically high percentage of Irish infants still breastfed at 6 months; in Ireland, this figure is usually approximately 15%.
The rate of reported food allergy in siblings of this cohort (sourced from unconfirmed parental reports rather than from healthcare record searches) is higher than the general population, which may have contributed to parental desire to enrol in this study.The rare (1%) positive SARS‐CoV‐2 antibody tests at 6 months suggesting recent or current infection imply that in Ireland, at least, newborn babies, traditionally considered to be particularly vulnerable to viral infection, appear to have been largely protected from SARS‐CoV‐2 exposure during the first COVID‐19 lockdown in 2020.The next stage of the CORAL study commenced in February 2021. It involves a review of the participants at 12 months with skin prick testing for common food and aeroallergens, a further questionnaire, stool sample and SARS‐CoV‐2 antibody test and peripheral blood sample for RNA sequencing to determine host immune responses to the COVID‐19 lockdown.
CONFLICT OF INTEREST
JO'BH is a board member of Clemens Von Pirquet Foundation. No other conflicts declared.
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