Younger children and COVID vaccines: 5-11 year olds

News

18 Nov 2021

Children do get COVID-19, and we have seen much higher rates of COVID infection in children in 2021 in Aotearoa/New Zealand (NZ) than in 2020. However, less than two in one hundred children in the 5-11 year age group will have more than mild symptoms needing hospitalisation. The Delta variant is much more infectious, leading to higher case numbers across all age groups. Due to increased vaccination coverage in adults and teenagers, children less than 12 years will make up an increasingly large proportion of cases.

So far in the ‘August Auckland’ outbreak of over 5000 people, one third are aged less than 20 years, of whom half are aged ten years or less. Yet almost all children and adolescents have been managed, without the need for hospitalisation, in isolation facilities or at home with supportive care. When compared with older or even younger adults, hospital-level care for children remains exceptionally uncommon, even with Delta. Around 1% of children and young people have needed hospitalisation in over 1500 cases aged up to 19 years, including for reasons such as unwell carers rather than their own illness. There have been no intensive care admissions for children to date in NZ. The rare post-infectious inflammatory syndrome (PIMS-TS) has not been seen as yet in NZ although Australia now reports up over a dozen cases after tens of thousands of cases of COVID in children and teenagers. Internationally ‘Long COVID’ has been reported in children although at a much lower rate than adults.

The Pfizer COVID-19 vaccine has been granted Emergency Use Authorisation by the Federal Drug Administration (FDA) in the USA for 5 – 11-year-old children, using one-third of the current adult dose. Vaccination of this age group has commenced in the US and is being actively considered by Canada, Australia and several European countries, although none are vaccinating this age group as yet. We await a review by Medsafe before considering inclusion into the COVID programme led by the Ministry of Health.

Important considerations in the vaccination of 5-11-year-olds in either a programmatic or targeted manner include:

1. Available evidence from the recent Pfizer trial which enrolled just over 2200 children randomised 2:1 in the clinical trial with just over 1500 receiving active vaccine indicates that the vaccine is equivalently immunogenic to young adults using a 1/3 dose, with lower levels of common post-vaccine adverse events.

2. As hospitalisation/death due to COVID are rare/very rare and longer-term consequences (PIMS-TS; long-COVID) also very rare, the direct health benefits to this age group themselves of COVID-19 vaccination are less but are not zero.

3. There are potentially substantial non-health benefits with lessened disruption to school and sports; travel; family events from limiting COVID infections in children. Importantly also are possible reductions in community transmission including reduction of within-household transmission.

4. As the current clinical trial was relatively small, we do not know whether more rare side effects will be seen in children also. The rare side effect of peri/myocarditis is seen more amongst in adolescents and young adults. However, this adverse event was identified quickly in international vaccine roll-outs and has informed programmes globally. In the US, as millions of children are vaccinated over the coming months, this will provide more certainty for children awaiting the vaccine in Aotearoa/NZ whilst we currently have much lower COVID incidence.

5. Equity is a priority consideration for both the health and non-health vaccine benefits, with a substantially higher disease burden of COVID amongst Māori and Pacific communities in Aotearoa/NZ. In Auckland, 70% of the over 5000 COVID cases in the last 3 months have been amongst Māori or Pacific peoples. Hospitalisations and rare outcomes like PIM-TS are inequitably distributed to non-European ethnicity seen internationally and in the current Aotearoa/NZ experience. Challenges include managing sick people within whānau and households with a range of social disadvantages such as crowded and insecure housing. In addition, other comorbidities such as bronchiectasis, rheumatic fever are already experienced in high rates in certain communities; the burden COVID will add to these alongside risk from the increased transmission to others in inter-generational households.

6. Impact and incorporation into other crucial childhood vaccinations programmes should also be maximised in the approach to COVID vaccination of children. With school closures and resource direction to COVID vaccination, childhood vaccination rates have declined in certain areas, particularly timeliness of delivery of the infant course and the delivery of the second year of life MMR vaccine. The HPV school programme and Māori infant vaccination need to be equally well resourced and enabled with COVID to protect children from the diseases such as measles which are directly life-threatening for them and are likely to be re-introduced with opening borders.

Finally, as children return to school and we await additional data, ongoing use of important strategies will help in minimising COVID impact on whanau including getting the best possible coverage of all aged 12 years and older, use of masks, social distancing, and staying home when sick with appropriate paid sick/parental leave.

References:

https://www.health.govt.nz/our-work/diseases-and-conditions/covid-19-novel-coronavirus/covid-19-data-and-statistics/covid-19-case-demographics#aug-2021

Walter EB, Talaat KR et al. Evaluation of the BNT162b2 Covid-19 Vaccine in Children 5 to 11 Years of Age. New Engl J Med. Nov 9, 2021 DOI: 10.1056/NEJMoa2116298

World Health Organisation Interim statement on Covid-19 vaccination for children and adolescents Nov 24, 2021: https://www.who.int/news/item/24-11-2021-interim-statement-on-covid-19-…  

Zimmerman P et al. Should children be vaccinated against COVID-19? Arch Dis Child 2021 Nov 3; doi: 10.1136/archdischild-2021-323040

Last updated: 25 November 2021