A new variant of coronavirus first discovered in the UK, also known as B.1.1.7, is present in at least 37 countries as well as Hong Kong and Taiwan, according to CNN's count.
Experts say that while the variant appears to be more transmissible than other Covid-19 strains, there is no evidence it is deadlier or causes more severe disease.
Test results are expected this week from labs that are studying whether the variant might pose a challenge to coronavirus vaccines, according to a World Health Organization official.
The UK variant is separate from another one first identified in South Africa.
The 37 countries are: United Kingdom, Australia, Belgium, Brazil, Canada, Chile, China, Denmark, Finland, France, Germany, Iceland, India, Ireland, Israel, Italy, Jamaica, Japan, Jordan, Lebanon, Malta, Luxembourg, Netherlands, New Zealand, Norway, Pakistan, Portugal, United Arab Emirates, Singapore, South Korea, Spain, Sweden, Switzerland, Thailand, Turkey, United States (including cases in Florida, California and Colorado) and Vietnam.