The Director-General of the World Health Organisation (WHO), Tedros Adhanom Ghebreyesus, said that COVID-19 booster shots should be delayed as priority should be given to raising vaccination rates in countries where only 1% or 2% of the population has been inoculated, Reuters news agency reported on Monday.

Ghebreyesus was quoted as telling a news conference that if vaccination rates are not raised globally, stronger variants of the coronavirus could develop and vaccines intended as booster shots should be donated to countries where people have not received their first or second doses.

"In addition, there is a debate about whether booster shots are effective at all," Ghebreyesus said, adding those whose immune system is compromised should get a booster shot, though they represent only small percentage of the population.

The WHO had said last week that current data does not indicate that COVID-19 booster shots are needed and that the most vulnerable people worldwide should be fully vaccinated before high-income countries deploy a top-up.