Novavax Inc. jumped after US regulators fully approved its Covid vaccine, easing investors’ concerns after the clearance was delayed and US Health and Human Services Secretary Robert F. Kennedy Jr. raised doubts about its efficacy.

Novavax originally showed its vaccine was safe and effective in a 30,000-person clinical trial. The FDA had been on track to grant Novavax full approval – without restrictions -- by its April 1 target date, according to two people with direct knowledge of the situation who spoke on condition of anonymity to discuss confidential agency matters.

The vaccine will only be available to those at high risk from COVID—excluding those who may need it to protect a relative or friend.