The discovery could add to new alarm in the pandemic after similar variants were announced in Britain and South Africa, leading to the swift return of international travel restrictions and other measures during a major holiday season.

“It’s a separate lineage from the U.K. and South Africa,” the head of the Africa Centers for Disease Control and Prevention, John Nkengasong, told reporters. He said the Nigeria CDC and the African Center of Excellence for Genomics of Infectious Diseases would analyze more samples…

The variant in Nigeria, Africa’s most populous country, was found in two patient samples collected on Aug. 3 and on Oct. 9 in Osun state, according to a working research paper seen by The Associated Press.

Unlike the variant seen in the U.K., “we haven’t observed such rapid rise of the lineage in Nigeria and do not have evidence to indicate that the P681H variant is contributing to increased transmission of the virus in Nigeria. However, the relative difference in scale of genomic surveillance in Nigeria vs. the U.K. may imply a reduced power to detect such changes,” the paper says.