Health Canada has authorized another Moderna bivalent COVID-19 booster vaccine for those 18 years and older to tackle the Omicron BA.4 and BA.5 subvariants of COVID-19, two months after the company’s first bivalent booster was approved.
Moderna’s first bivalent shot for the BA.1 subvariant was approved in early September, while Pfizer’s BA.4, BA.5 bivalent COVID-19 vaccine — that company’s first bivalent booster — was given the go-ahead earlier in October. BA.4 and BA.5 are the dominant strains circulating now in Canada, according to the health agency.
Health Canada deemed Moderna’s latest “Spikevax” booster “safe and effective” after a “thorough and independent scientific review of the evidence.”
“Clinical trial results showed that a booster dose of the bivalent Moderna Spikevax vaccine triggers a strong immune response against both Omicron (BA.4/BA.5) and the original SARS-CoV-2 virus strains,” Health Canada said in a statement Thursday.
“This adapted vaccine has a similar safety profile to the previously approved Moderna Spikevax boosters, with the same mild adverse reactions that resolved quickly.”
Health Canada said it and the Public Health Agency of Canada will closely monitor the vaccine’s safety and promises to take action if any concerns are identified.
According to the National Advisory Committee on Immunization (NACI), there is currently no evidence to suggest that there is any meaningful difference in protection between the bivalent boosters targetting the BA.1 versus the BA.4/5 subvariants. There is also no clinical trial directly comparing the Moderna (50 mcg) and Pfizer-BioNTech (30 mcg) bivalent boosters.
For those who got Moderna’s first bivalent booster, Health Canada said in September that clinical data shows that the booster still generates “a good immune response against the Omicron BA.4 and BA.5 subvariants, and is expected to extend the durability of protection.”
NACI recommends that fall COVID-19 booster doses be offered six months after a previous COVID-19 vaccine or infection of the virus. A shorter interval of three months may be considered, especially for those with heightened epidemiological risks, but it is not expected that a booster dose will be routinely provided every three months, according to NACI.
Moderna is projecting US$4.5 billion to US$5.5 billion in sales from COVID-19 vaccine contracts in 2023, down from analysts’ estimates of US$9.5 billion as demand has dropped and production has been stalled due to quality control issues at its contract manufacturing partner.