The World Health Organization's director-general Tedros Adhanom Ghebreyesus said many vaccinated people were wrongly thinking the jab meant they no longer needed to take any other precautions.

Fully-immunised people must stick with measures to avoid catching the virus and passing it on, Tedros insisted, spelling out how the more contagious Delta meant the vaccines were not as effective against transmission.

"We're concerned about the false sense of security that vaccines have ended the pandemic and people who are vaccinated do not need to take any other precautions," Tedros told reporters.

"Vaccines save lives but they do not fully prevent transmission.

NS