The result was announced Friday following genetic sequencing of the patients' samples by the National Institute of Hygiene and Epidemiology. The Indian variant, B.1.167, is a "double mutant" strain, which is recorded for the first time in Vietnam.

The Vietnamese man was a receptionist at Nhu Nguyet 2 hotel in the northern province of Yen Bai. The 63-year-old man made contact with the group of Indian experts as they came to the hotel on April 18 for quarantine. Among 11 Indians, four had been confirmed as Covid-19 cases.

The B.1.617 strain contains two key mutations called E484Q and L452R, which have been found separately in other variants but not together in a single strain. These mutations have been shown to make the virus more transmissible and to be less susceptible to neutralizing antibodies.

The World Health Organization (WHO) said the predominant lineage of B.1.617 was first identified in India last December, although an earlier version was spotted in October 2020. The WHO has described it as a "variant of interest", suggesting it may have mutations that would make the virus more transmissible, cause more severe disease or evade vaccine immunity. Other strains with known risks, such as those first detected in the United Kingdom, Brazil and South Africa, have been categorized as "variants of concern," a higher threat level, Reuters reported.

The Indian variant has been found in at least 17 countries.

Vietnam's Minister of Health Nguyen Thanh Long said he is "deeply concerned about the risk of imported cases causing the fourth wave in the country." He asked leading institutes to conduct genetic sequencing of recent entrants who are infected with the coronavirus to figure out appropriate preventative measures.

The Pasteur Institute in HCMC previously found that nearly 86 percent of imported positive cases from Cambodia carry the B1.1.7 variant (U.K.), and over 14 percent the B.1.351 variant (South Africa).

Vietnam has recorded almost all kinds of new coronavirus variants.

After over a month of no community transmissions, the country has recorded 13 new local cases since Thursday, starting with a migrant worker from Japan who tested positive two days after finishing his two-week quarantine.