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Initial Effectiveness of mRNA-1273 Against SARS-CoV-2 Infection and Hospitalization in Young Children
Mary Aglipay1,2, Jonathon L Maguire2,3,4,5, Sarah Swayze6
1Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
Insights
The Moderna mRNA-1273 vaccine shows strong effectiveness in young children. It significantly reduced symptomatic SARS-CoV-2 infections and COVID-19 hospitalizations in children aged 6 months to 5 years.
Area of Science:
- Pediatric infectious diseases
- Vaccinology
- Public health
Background:
- Limited data exists on mRNA-1273 (Moderna) vaccine effectiveness in children aged 6 months to 5 years.
- Assessing vaccine effectiveness (VE) in this age group is crucial for public health strategies.
Purpose of the Study:
- To evaluate the effectiveness of the mRNA-1273 vaccine against symptomatic SARS-CoV-2 infection and COVID-19-related hospitalization in children aged 6 months to 5 years.
- To determine if VE varied between younger (6 months to <2 years) and older (2 to 5 years) children.
Main Methods:
- A test-negative study design was employed using linked health administrative data in Ontario, Canada.
- Symptomatic children aged 6 months to 5 years tested for SARS-CoV-2 via real-time PCR were included.
- The study period was from July 28 to December 31, 2022, focusing on symptomatic infection and COVID-19 hospitalization.
Main Results:
- The study included 572 test-positive cases and 3467 test-negative controls.
- mRNA-1273 receipt was associated with high vaccine effectiveness against symptomatic SARS-CoV-2 infection (90%) and COVID-19-related hospitalization (82%) at least 7 days post-second dose.
- No significant difference in VE was observed between the age groups (6 months to <2 years vs 2 to 5 years).
Conclusions:
- The mRNA-1273 vaccine demonstrated strong initial effectiveness in preventing symptomatic SARS-CoV-2 infection and hospitalization in young children.
- Findings support the use of mRNA-1273 for this pediatric population.
- Further investigation is warranted to ascertain the long-term protective effects of the vaccine.
Background:
Data on mRNA-1273 (Moderna) vaccine effectiveness (VE) in children aged 6 months to 5 years are limited. The objectives of this study were to assess mRNA-1273 vaccine effectiveness against symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19)-related hospitalization among children aged 6 months to 5 years during the initial 5 months of the vaccination campaign rollout, as well as to determine whether VE varied by age group (6 months to <2 years vs 2 to 5 years).
Methods:
We used a test-negative study with linked health administrative data in Ontario, Canada, to evaluate vaccine effectiveness of mRNA-1273 against symptomatic SARS-CoV-2 infection and COVID-19-related hospitalization from July 28 to December 31, 2022. Participants included symptomatic children aged 6 months to 5 years who were tested by real-time polymerase chain reaction. The primary outcome was symptomatic infection, and the secondary outcome was COVID-19-related hospitalization.
Results:
We included 572 test-positive cases and 3467 test-negative controls. Receipt of mRNA-1273 was associated with reduced symptomatic SARS-CoV-2 infection (VE, 90%; 95% CI, 53%-99%) and COVID-19-related hospitalization (VE, 82%; 95% CI, 4%-99%) ≥7 days after the second dose. We were unable to detect heterogeneity in VE across age groups.
Conclusions:
Our findings suggest that mRNA-1273 vaccine effectiveness was initially strong against symptomatic SARS-CoV-2 infection and hospitalization in children aged 6 months to 5 years. Further research is needed to understand long-term effectiveness.
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