Health officials spray disinfectant as part of preventative measures against COVID-19, in a shopping mall in Pyongyang on September 27, 2021. (Photo: AFP/VNA)

The number of people having fever symptons has exploded across North Korea since late April, taking the reported total to 820,620.

North Korean leader Kim Jong Un said on Saturday that the spread of COVID-19 had thrust the country into "great turmoil" and asked health officials to learn from the experience of other advanced countries, including China.

The UN on Friday insisted readiness to help Pyongyang in fighting the coronavirus.

European health officials have warned that Omicron strains BA.4 and BA. 5 can escape vaccines and immunity.

Amid fear of a ''summer wave,'' last Friday the European Centre for Disease Prevention and Control (ECDC) became the first public authority to label both the strains as ''variants of concern.'' BA.4 and BA.5 were first detected in South Africa in January and February 2022.

According to the ECDC, the two sub-lineages can lead to a new epidemic wave across Europe. The ECDC also urged people of all ages to get the basic and booster shots of the COVID-19 vaccine to help protect against new variants as immunity "weakens".