On 29 September 2022 the Therapeutic Goods Administration (TGA) provisionally approved Comirnaty (Pfizer) COVID-19 vaccine for use in children aged 6 months to 4 years.
ATAGI has evaluated data on immunogenicity, efficacy, and safety to consider the use of the Pfizer 6 months to 4 years COVID-19 vaccine in this age group.
The COVID-19 Moderna <5 years vaccine has already been recommended by ATAGI on 3 August 2022 in this age group, for high-risk children (as identified below). There is no preference for either the Moderna <5 years or Pfizer 6 months to 4 years COVID-19 vaccine in high-risk children aged 6 months to <5 years; however completion of a primary schedule with the same brand of vaccine is recommended. Further advice will be included in the ATAGI clinical guidance in due course.
ATAGI does not currently recommend vaccination for children aged 6 months to <5 years who are not in the below risk categories for severe COVID-19. Further information regarding the low risk of severe COVID-19 in healthy children aged
6 months to <5 years is available in this statement.
ATAGI recommends the Pfizer 6 month to 4 years COVID-19 vaccine as a primary course of vaccination against SARS-CoV-2 for children aged 6 months to 4 years with severe immunocompromise, complex or multiple health conditions, or disability with significant or complex health needs.
This includes children with the following or similar conditions:
- Severe primary or secondary immunodeficiency, including those undergoing treatment for cancer, or on immunosuppressive treatments as listed in the ATAGI advice on 3rd primary doses of COVID-19 vaccine in individuals who are severely immunocompromised;
- Bone marrow or stem cell transplant, or chimeric antigen T-cell (CAR-T) therapy recipients;
- Complex congenital cardiac disease;
- Structural airway anomalies or chronic lung disease;
- Type 1 diabetes mellitus;
- Chronic neurological or neuromuscular conditions; or
- A disability with significant or complex health needs, such as severe cerebral palsy or Down Syndrome (Trisomy 21).
The Pfizer 6 months to 4 years vaccine requires 3 primary doses, each containing 3mcg of mRNA. ATAGI recommends an interval of 8 weeks between each dose. Children with severe immunocompromise are also recommended to receive
3 primary doses. ATAGI will update this recommendation if future evidence demonstrates a need for additional doses.
ATAGI currently recommends the administration of COVID-19 vaccines be deferred for 3 months after a confirmed SARS-CoV-2 infection. Vaccination after this interval is likely to provide a better immunological response and optimise the duration of protection.
The Pfizer vaccine for 6 months to 4 year old children (Pfizer 6 month to 4 years vaccine) is an mRNA vaccine. Each 0.2mL dose contains 3 micrograms of mRNA. Results of a recent clinical trial demonstrate the Pfizer 6 month to 4 years vaccine is effective at protecting against COVID-19 disease in children who have not yet been infected with SARS-CoV-2, and most side effects are short-term. However, there are little data available regarding the impact of COVID-19 vaccines on routine immunisations recommended in this age group. Furthermore, severe COVID-19 in this cohort is very rare.
The recommended primary course dosing schedule is 3 doses, 8 weeks apart. Whilst this differs from the interval used in the clinical trial conducted by Pfizer, research suggests a longer dose interval may improve vaccine effectiveness and reduce the risk of rare side effects, including myocarditis or pericarditis.
Recent safety data from the United States, indicates that the Pfizer 6 month to 4 years vaccine has a good safety profile. As at 1 September 2022, over 890,000 doses have been administered with only a small number of adverse events following immunisation reported.
ATAGI will continue to evaluate further data on the safety and efficacy of vaccinations against COVID-19 in this age group and provide updated recommendations as required.