Objectives To assess the reactogenicity, measure the adaptive immune responses and trackthe long-term immune memory in healthy children and adults as well as pediatric patientsreceiving the COVID-19 vaccines-BNT162b2, CoronaVac-chosen by the Hong Kong Government;to compare the reactogenicity and immunogenicity across the vaccines used for thesechildren and adults.Hypothesis to be tested The safety profile and the magnitude and durability of immuneresponses to the COVID-19 vaccines in children are non-inferior to those in adults.Design and subjects A single-site, comparative nonrandomised clinical trial for 450healthy individuals or patients under 18 years old and one or both healthy parents andunrelated adults to receive one of COVID-19 vaccines by intramuscular injection (andintradermal injection)Instruments Mobile app for subjects to record adverse effects, enzyme-linkedimmunosorbent assay, plaque reduction neutralization assay, luciferaseimmunoprecipitation system assay and flow cytometry.Interventions BNT162b2 and CoronaVac, by intramuscular or intradermal routeMain outcome measures Types and frequencies of adverse effects within 7 days, and changesand peaks of antibody levels and antigen-specific memory T cell responses for 3 years.
Not Provided
Biological: Tozinameran
mRNA vaccine developed by BioNTech against COVID-19
Other Name: BNT162b2
Biological: CoronaVac
Inactivated virus vaccine developed by SinoVac against COVID-19, intramuscular
Biological: CoronaVac, intradermal
Inactivated virus vaccine developed by SinoVac against COVID-19, intradermal
Inclusion Criteria:
1. informed consent from the parents or a legally acceptable representative for an
underage participant
2. biological parents of students enrolled in the trial or unrelated healthy adults
3. ability to adhere to the follow-up schedules
4. willingness to report reactogenicity daily for 7 days post dose 1, 2 and 3 (and 4)
proactively
5. willingness to receive that vaccine available for that particular recruitment period
(as student-parent pair, if applicable)
6. good past health, including pre-existing clinically stable disease, such as
paediatric or immune disorders
7. prior COVID-19 (for COVID-19 survivor subgroup)
Exclusion Criteria:
1. reported pregnancy or breastfeeding
Queen Mary Hospital
Hong Kong, Hong Kong, China
Yu Lung Lau, MD, Principal Investigator
The University of Hong Kong