J&J recipients who were administered Moderna or Pfizer boosters showed significantly higher antibody counts compared to those who received a booster of the same vaccine.
The move, set to be formally announced on Wednesday, will end a 19-month curb on nonessential travel into the U.S. put in place at the onset of the pandemic.
The Moderna boss believes enough vaccines could be available by the middle of next year to immunize the entire world—a challenge amid supply shortages and inequity in poorer nations.
The incidence of the side effect remains extremely rare with only 833 cases being reported worldwide from about 592 million administered doses of the AstraZeneca vaccine.
As part of the swap deal, Australia will receive 500,000 doses of the Pfizer Covid-19 vaccine from Singapore this week and return the same number of doses in December.