KEY POINTS
  • New, more contagious mutated variants of the coronavirus are "highly problematic" and could cause more cases and hospitalizations, the head of the World Health Organization said on Monday.
  • The WHO was alerted over the weekend of a new variant identified in Japan, WHO Director-General Tedros Adhanom Ghebreyesus said.
  • Japan's infectious disease institute said it's difficult to immediately determine how infectious the new strain is and the effectiveness of vaccines against it.
Director General of the World Health Organization (WHO) Tedros Adhanom Ghebreyesus attends a news conference on the situation of the coronavirus (COVID-2019), in Geneva, Switzerland.

New, more contagious mutated variants of the coronavirus are "highly problematic" and could cause more cases and hospitalizations if the virus' spread isn't immediately suppressed, the head of the World Health Organization said on Monday.

The global health agency was alerted over the weekend of a new Covid-19 strain discovered in Japan, WHO Director-General Tedros Adhanom Ghebreyesus said during a press briefing. On Sunday, Japan's National Institute of Infectious Diseases said it discovered a new coronavirus variant in four travelers arriving from Brazil.