Vice President Harris's trip from Singapore to Vietnam was delayed by more than three hours after his staff were apprised of a "recent possible unusual health incident" in Hanoi, according to a statement from the US Embassy in Vietnam.
The "unusual health event"—which the US State Department refers to mysterious symptoms that has affected dozens of Americans working in embassies and consulates around the world—affected embassy staff in Vietnam but the vice president's staff. None of.
US officials still do not know what causes these symptoms, commonly referred to as "Havana Syndrome", but there are theories that include targeted microwave or sonic attacks. Havana syndrome has affected more than 200 US officials and their family members around the world in countries such as Cuba and China.
NBC News reported that at least two US personnel in Hanoi would be kicked out of the country following incidents of Havana Syndrome over the weekend. NPR has not independently confirmed this reporting.
The embassy statement said the decision to continue as the Vice President was taken "after careful evaluation".
Harris is in Southeast Asia for a week-long visit, his second international trip while in office, to help the administration rebuild ties with allies in the region as China expands its influence.