White House decision over Johnson & Johnson's booster shots will likely take weeks

It will be weeks before the Biden administration is expected to have enough data to guide its planning on booster doses for Americans who received Johnson & Johnson's COVID-19 vaccine, say multiple people familiar with the administration's deliberations. Top federal health officials are waiting for results from studies run by the drug maker and a government-backed trial.

The White House said Wednesday that Amercians who received Pfizer and Moderna shots should get booster shots eight months after their second dose, and at the same time advised that Johnson & Johnson vaccine recipients would eventually also need an additional shot. Some 13.8 million Americans have received the drug maker's single-shot vaccine. However, officials have yet to decide whether those who took the Johnson & Johnson shot should receive a second round of that vaccine or switch to an additional shot from the other vaccine makers.