Federal health officials are asking the White House to push back the start of a planned Covid-19 booster campaign, at least for the Moderna Inc. and Johnson & Johnson vaccines, people familiar with the discussions said.

The Food and Drug Administration needs more time to collect and assess the data on safety and efficacy, the people said. Centers for Disease Control and Prevention Director Rochelle Walensky and Acting FDA Commissioner Janet Woodcock made the recommendation Thursday in a meeting with Jeffrey Zients, the White House coronavirus coordinator, one of the people said.