>COVID-19 vaccinations for children have been flagged as a necessary part of the fight against the Delta strain in New South Wales.
I'm sure the parents of South Wales are all on board with this.
Could be 'brainwave entrainment'.
Neural oscillation and cognitive functions
The functional role of neural oscillations is still not fully understood;[7] however they have been shown to correlate with emotional responses, motor control, and a number of cognitive functions including information transfer, perception, and memory.[8][9][10] Specifically, neural oscillations, in particular theta activity, are extensively linked to memory function, and coupling between theta and gamma activity is considered to be vital for memory functions, including episodic memory.
https://en.wikipedia.org/wiki/Brainwave_entrainment