Moderna says new booster appears effective against Omicron subvariants

Moderna Inc. says its bivalent vaccine, an updated version of a COVID-19 booster shot, effectively offers protection against Omicron subvariants BA.4 and BA.5.

In a press release, Moderna says its mRNA bivalent vaccine has been developed to target the first Omicron variant and the initial COVID-19 strain in a single dose.

“One month after administration in previously vaccinated and boosted participants, a 50 [microgram] booster dose… elicited potent neutralizing antibody responses against the Omicron subvariants BA.4 and BA.5 in all participants regardless of prior infection,” Moderna Inc. said.

The pharmaceutical giant notes the shot did not generate as many antibodies as it did against the original Omicron variant despite the early promise in protection being shown against both subvariants.

The third dose of Moderna’s prototype booster was shown to be effective against Delta and BA.1 infection and hospitalization in observational studies, the company noted.

The complete data has not yet been made available for scientists to examine.

The bivalent mRNA shot is not yet authorized in the U.S. or Canada, but the company hopes to get approval sometime in the fall.

Omicron’s BA.4 and BA.5 have been rapidly spreading in the U.S. as health experts stress the subvariants’ ability to evade immunity and result in reinfections. There are fears that BA.4 and BA.5 may cause more severe illness.

In June, Ontario’s chief medical officer of health said additional booster shots would begin to roll out sometime in the fall.

Dr. Kieran Moore confirmed that Ontario would purchase more than six million doses of flu vaccine and expects to offer further doses against COVID-19.

Kids starting to get vaccinated in U.S. following FDA approval

The Food and Drug Administration (FDA) greenlighted the Moderna and Pfizer kid shots on Friday, and the Centers for Disease Control and Prevention (CDC) recommended them Saturday.

In the U.S., COVID-19 vaccines were first tested and given in late 2020 to health care workers and older adults. Teens and school-age kids were added last year.

The CDC advises vaccination even for those who already had COVID-19 to protect against reinfection and says it is OK to get other vaccines simultaneously. There’s Pfizer’s three-shot series or Moderna’s two shots for the littlest kids.

“Some parents are afraid that the younger the child, the more vulnerable they might be to vaccine side effects,” said Dr. Pam Zeitlin, director of pediatric medicine at National Jewish Health in Denver.

“But that’s not what Pfizer and Moderna studies found. Side effects were similar to what is seen with other childhood vaccines — fever, irritability and fatigue.”