By June 2021, the Lambda variant had begun to spread through South America and was detected in twenty-nine countries in total, especially in Argentina, Chile and Ecuador.[1][3] The WHO designated the Lambda variant as a "variant of interest" on 14 June 2021.[3] In mid-June 2021, 90.6% of new COVID-19 cases in Arequipa and 78.1% of new cases in Cusco were the Lambda variant according to the Peruvian Ministry of Health.[4]