STOCKHOLM, March 1 (Xinhua) -- The number of COVID-19 patients in intensive care has increased dramatically in Sweden. In ten days, their number has jumped from 197 to 240, with many of them admitted in the past two days, the TT news agency reported on Monday.

More than half of the country's regions have registered an increase in the number of seriously ill COVID-19 patients. In relation to its number of inhabitants, the Vasterbotten region in the northern part of Sweden is worst off. Incidentally, in February it was the first region to record a major outbreak connected to the mutated strain of the virus first discovered in Britain.

"It is always worrying if a small region receives a large influx of patients," Taha Alexandersson, deputy director of crisis response at the Swedish National Board of Health and Welfare, told TT. "The Swedish health care system is based on regions being able to help each other, but if several regions have it just as tough, it can be difficult. In the northern regions, there is a great habit of transporting patients, but the resources are not endless."

The Stockholm region has also recorded a dramatic 70 percent increase in the past ten days in the number of patients requiring intensive care. The situation is not as bad as it was during the peak of the second wave, but the region's director of health and medical care believes the third wave had arrived.

"You can look at it that way," Johan Bratt told Swedish Television News. "But what's positive is that nearly all nursing home residents have been vaccinated, so the frailest are protected."

As the world is struggling to contain the pandemic, vaccination is underway in some countries with the already-authorized coronavirus vaccines.

Meanwhile, 256 candidate vaccines are still being developed worldwide -- 74 of them in clinical trials -- in countries including Germany, China, Russia, Britain and the United States, according to information released by the World Health Organization on Feb. 26.