It could take two weeks or longer for federal health agencies to gather and analyze enough data to determine conclusively whether there is a link between Johnson & Johnson’s coronavirus vaccine and reports of rare but severe blood clots in recipients, according to two senior administration health officials. Federal officials called for a nationwide pause in the shot Tuesday, predicting then it might last only a few days. The current investigation is already intensifying concerns by state officials that the public will lose overall confidence in Covid-19 vaccines. The data gap may not be fully resolved by next Friday, when the Centers for Disease Control and Prevention’s vaccine advisory panel is set to gather for the second time to discuss the concerns about the shot, the two senior health officials told POLITICO. Federal health agencies have said they will look to the panel for guidance on how to move forward; one likely scenario is that the panel, and Biden officials, will decide to issue a stronger warning next week about potential risks or restrict eligibility while pledging to continue studying the matter.