Africa has officially entered the fourth wave of the COVID-19 pandemic partly due to the Omicron variant, Matshidiso Moeti, the World Health Organization's (WHO) Regional Director for Africa, said in an online briefing on Tuesday.

The region has seen an 83 percent increase in new cases the past week compared to the previous one, the fastest surge recorded since May last year, Moeti said.

She stressed the importance of vaccination as Africa is entering the year-end holiday season.

"We are at a pivotal moment, and complacency is our enemy," Moeti said, noting that the continent is seeing more consistent delivery of vaccine doses.