- 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.
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.
The variant appears to have some of the same mutations as other strains discovered in the United Kingdom and South Africa, the institute said. Those virus mutations, while highly infectious, don't appear to make people more ill from the virus, health experts have 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.
As viruses spread, they're expected to mutate over time as the spikes on their surfaces change, the Centers for Disease Control and Prevention says. However, the CDC warns that it's not yet known how widespread the new mutations are.
"The more the virus spreads, the higher the chance of new changes to the virus," Tedros said at the WHO's headquarters in Geneva, noting that the new variants appear to be more contagious than previous strains.
"This can drive a surge of cases and hospitalizations, which is highly problematic for health workers and hospitals already close to breaking point. This is especially true where public health and social measures have already broken down," Tedros said.
Dr. Mike Ryan, executive director of the WHO's health emergencies program, likened the mutating virus to entering the second half of a football game. While it doesn't change the rules of the game, it does give the "virus some new energy," he said.
"It adds to the challenge you face because the opposition is bringing on some new players to the field," Ryan said. "It doesn't change what we need to do to win. It just changes the strength of the opponent and, in that sense, we have to take from that that we have to redouble our efforts."
Limiting the coronavirus' transmission will prevent the mutations from escalating, Tedros said. Current public health guidance on how to slow the spread of previous strains, like wearing a face covering, physical distancing and washing your hands, will work to prevent the diseases' spread, he said.
Another promising sign: The existing vaccines don't appear to be any less effective against the new mutations, though they may need to be tweaked in the future, Tedros said. At a press briefing last week, Tedros emphasized that the vaccines needed to be distributed more equitably across the globe to help stop the new mutations from proliferating.
The coronavirus has infected more than 90.4 million people across the globe and has killed at least 1.9 million people, according to data compiled by Johns Hopkins University. Countries are now racing to roll out their initial doses of Covid-19 vaccines to reduce the stress on hospitals.
British Prime Minister Boris Johnson instituted additional lockdown measures on England last week to prevent a new strain it discovered, known as B.1.1.7, from burdening the nation's hospitals.
U.K. health officials announced the discovery of the new variant on Dec. 14. It initially appeared in southeast England, according to a WHO report. The mutation quickly replaced previous strains of the virus in a matter of weeks and had traveled to at least 31 countries by Dec. 30, the report said.
In the United States, there are now at least 63 Covid-19 cases with the B.1.1.7 variant, the CDC said Friday. Officials from the agency warned in December that new, highly infectious variants could lead to more cases, which would prompt additional hospitalizations and fatalities, at a time when hospitals are already overburdened.
There were 129,229 people hospitalized with Covid-19, as of Sunday — nearly double the number of patients since mid-November, before the holiday season, according to data from the COVID Tracking Project, which is run by journalists at The Atlantic.
—CNBC's Sam Meredith contributed to this report.