ATAGI advises that the Moderna bivalent BA.4/5 vaccine can be used in eligible adolescents and adults aged 12 years or older who are recommended (or advised to consider) a COVID-19 booster dose according to the .
All currently available COVID-19 vaccines are anticipated to provide benefit as a booster dose, however bivalent booster vaccines, including the Moderna bivalent BA.4/5 vaccine and Pfizer bivalent BA.4/5 vaccine, are preferred over other vaccines.
The Moderna bivalent BA.4/5 vaccine is not registered for use in children aged under 12 years or as a primary series. Currently, the Pfizer original COVID-19 vaccine (orange cap) is the only formulation recommended for use in this age group. Providers can refer to the webpage to check which vaccines are recommended by age group.
The Moderna bivalent BA.4/5 vaccine contains 25mcg of the SARS-CoV-2 BA.4/5 Omicron subvariant spike protein mRNA and 25mcg of the ancestral strain spike protein mRNA.
Rationale
Immunogenicity data from the Moderna clinical trial demonstrate a trend towards the BA.4/5 vaccine inducing higher neutralising activity against Omicron subvariants (including BQ.1 and XBB) than original vaccines or BA.1-containing vaccines.1 This study reported 5.1-6.3 times greater neutralising antibody levels against the BA.4/5 Omicron subvariants at 1 month after a booster dose of Moderna bivalent BA.4/5 vaccine compared to Moderna original vaccine in adults aged 18 years and older who had previously received a primary series and booster dose of Moderna original vaccine.1
Early evidence suggests a booster dose of Moderna bivalent BA.4/5 vaccine provides greater protection against hospitalisation and death from severe Omicron disease compared to a booster dose of Moderna original vaccine at 1-3 months in adults (63.8% vs 38.6%, respectively).2 Very few cases of hospitalisation or death from severe Omicron disease have occurred in children aged less than 12 years.3
The very small risk of myocarditis or pericarditis following Moderna bivalent BA.4/5 vaccine does not appear to be greater than the risk after a first booster dose of Moderna original vaccine or a booster dose of Pfizer bivalent BA.4/5 vaccine in adolescents and adults aged 12 years and above at this time.4,5 There has been no association between Modern bivalent BA.4/5 vaccine and thrombotic stroke.4,5
ATAGI will continue to monitor the emerging evidence related to bivalent vaccines and the changing COVID-19 epidemiology.
References
- Chalkias S, Whatley J, Eder F, et al. Safety and Immunogenicity of Omicron BA.4/BA.5 Bivalent Vaccine Against Covid-19. medRxiv (pre-print) 2022.12.11.22283166; doi: (Accessed 20/02/2023)
- Lin DY, Xu Y, Gu Y, et al. Effectiveness of Bivalent Boosters against Severe Omicron Infection. N Engl J Med. 2023 Jan 25. doi: 10.1056/NEJMc2215471. Epub ahead of print. PMID: 36734847. Available at: (Accessed 20/02/2023)
- Lin DY, Xu Y, Gu Y, et al. Effectiveness of Vaccination and Previous Infection Against Omicron Infection and Severe Outcomes in Children Under 12 Years of Age. medRxiv (pre-print) 2023.01.18.23284739; doi: (Accessed 20/02/2023)
- UK Health Security Agency. Coronavirus vaccine – summary of Yellow Card reporting – updated 3 February 2023. Available from: (Accessed 20/02/2023).
- Forshee R. Vaccines and Related Biological Products Advisory Committee (VRBPAC) presentation slides: January 26, 2023 meeting: Update on Original COVID-19 Vaccine and COVID-19 Vaccine, Bivalent Effectiveness and Safety. 2023. Available at: (Accessed 20/02/2023)
