Vice President Kamala Harris' trip to Hanoi, Vietnam, was delayed by a few hours after her office was made aware of a recent possible anomalous health incident" among U.S. officials in Hanoi. "Anomalous health incident" is how the United States government refers to the mysterious "Havana syndrome." First reported in 2016 by United States officials in Cuba, Havana syndrome has afflicted more than 130 U.S. officials over the past five years stationed in several countries overseas. Victims of the syndrome typically report strange experiences, like feelings of pressure or vibration and a screeching sound, and debilitating symptoms, including headaches, nausea, cognitive deficits, and trouble with seeing, hearing, or balancing. The vice president's office said that after "careful consideration," her team opted to continue with her Vietnam trip. A couple hours after the announcement, NBC News reported that a medical evacuation was called for two U.S. officials in Hanoi. The NBC report noted that "strange sounds" were involved in the incidents, and that Vietnam has seen past reports of possible Havana syndrome cases. NBC News reported in June that some U.S. officials believe that unknown adversaries used "devices intended to extract information from cellphones and other personal devices" that emitted electromagnetic waves powerful enough to cause debilitating symptoms. After realizing such devices had that effect, they then "weaponized the tactic to intentionally cause physical harm."