Cases of covid-19 have doubled in the past month and a half globally, from about three million weekly to six million today, the director-general of the World Health Organization (WHO) warned Wednesday..

"An increase in cases of infection means that there may be more hospitalizations and more deaths in the coming weeks," said Tedros Adhanom Ghebreyesus quoted by Lusa at a press conference in Geneva.

The WHO official estimated that most of the current infections originate in different countries from the BA.5 strain of the Omicron variant, which is so far "the most contagious known" since the start of the pandemic in 2020.

According to the latest data from the National Institute of Health Doutor Ricardo Jorge (INSA), released on Tuesday, the BA.5 strain was responsible for about 95% infections in the week between July 4 and 10.

BA.5 has been the dominant strain in Portugal since May and was, according to experts, one of the causes of the recent sixth wave of infections in the country.

On Monday, the European Centre for Disease Prevention and Control (ECDC) used the example of Portugal to predict that other countries in Europe may see an increase in covid-19 cases due to the BA.4 and BA.5 strains.

"The emergence of BA.4 and BA.5 in other European Union and European Economic Area (EU/EEA) countries is expected to result in increases in covid-19 cases, as observed in Portugal in recent months," the European agency estimated.

According to Tedros Adhanom Ghebreyesus, the coronavirus that causes covid-19 "will continue to evolve," forcing countries not to relax their pandemic response measures.

"Some countries have already dismantled parts of their response plan and are taking great risks," warned the WHO director-general, for whom new waves of infections can be expected and must be prevented from resulting in increased hospitalizations and deaths.