GENEVA, July 12 (AFP) - Fresh waves of COVID-19 infections show the pandemic is "nowhere near over", the World Health Organization's chief warned Tuesday (Jul 12), voicing concern the virus is "running freely".

Tedros Adhanom Ghebreyesus said he was worried that case numbers were continuing to rise, putting further pressure on stretched health systems and workers.

"New waves of the virus demonstrate again that COVID-19 is nowhere near over," he told a news conference, adding: "As the virus pushes at us, we must push back."

"The virus is running freely and countries are not effectively managing the disease burden based on their capacity, in terms of both hospitalisation for acute cases and the expanding number of people with post-COVID condition, often referred to as Long COVID," he said.

"As COVID-19 transmission and hospitalisations rise, governments must also deploy tried and tested measures like masking, improved ventilation and test and treat protocols," Tedros insisted.

The WHO's emergency committee on COVID-19 met on Friday via video-conference and determined the pandemic remains a Public Health Emergency of International Concern - the highest alarm the WHO can sound.

WHO emergencies director Michael Ryan told the meeting global COVID-19 cases reported to the WHO increased by 30 per cent in the last two weeks, largely driven by Omicron sub-variants BA.4, BA.5 and and the lifting of public health and social measures.

Ryan said recent changes in testing policies were hindering the detection of cases and the monitoring of virus evolution.

The committee stressed the need to reduce transmission of the virus as the implications of a pandemic caused by a new respiratory virus would not be fully understood, the WHO said in a statement on Monday.

The group voiced concern over steep reductions in testing, resulting in reduced surveillance and genomic sequencing.

"This impedes assessments of currently circulating and emerging variants of the virus," the WHO said, feeding the inability to interpret trends in transmission.

The committee said the trajectory of virus evolution and the characteristics of emerging variants remained "uncertain and unpredictable", with the absence of measures to reduce transmission increasing the likelihood of "new, fitter variants emerging, with different degrees of virulence, transmissibility, and immune escape potential".