US officials seek to know if third dose helps people with weak immunity

Federal health officials have signalled they're hunting ways to quickly learn if a third Covid vaccine dose might better protect organ transplant recipients and other patients with weak immune systems

Federal health officials have signalled they're hunting ways to quickly learn if a third COVID-19 vaccine dose might better protect organ transplant recipients and other patients with weak immune systems.

While the vaccines are strongly effective in most people, many Americans with immune-suppressing health problems remain in limbo after immunisation, uncertain how protected they really are. France and Israel already have begun offering an extra dose to transplant recipients and other immunocompromised people. In the US, those patients increasingly are pushing for -- even lying to get -- another shot, too.

Thursday, advisers to the Centers for Disease Control and Prevention reviewed some small studies that hint, but don't prove, a third dose might help at least some immunocompromised patients. The panel can't formally recommend an extra dose without the Food and Drug Administration's permission, but several advisers asked if the government could allow worried patients to sign up for one as part of a study.

"We are actively looking into ways that could be done," replied CDC's Dr Amanda Cohn. "Stay tuned. We are working through those issues.