She said research had already shown that in all the mutations of COVID-19 the virus adheres to a person’s cell more easily.
“So that’s one of the reasons why we’re seeing increased transmissibility,” she said.
Researchers are also exploring whether the virus has adapted specifically to spread differently in healthcare settings.
NSW Chief Health Officer Kerry Chant has said a person infected with the Delta variant at Sydney’s Bondi Junction Westfield caught the disease in a “scarily fleeting” encounter, according to CCTV footage.
“They are clearly facing each other but it is literally someone moving across from each other for a moment, close, but momentary,” Dr Chant said.
According to Chant, two other people may have been infected in the same manner.
Similarly, Jeroen Weimar, Victoria’s COVID-19 commander, has also previously said infections were occurring in situations where people had very little contact and had simply brushed past each other in a small shop.
Sydneysiders were first advised but then required to wear masks following the detection of the “fleeting contact” cases.
The WHO said people needed to take a more “fastidious” approach to physically distancing, washing their hands and wearing masks because these basic behaviours guard against all strains of the virus.