SARS-CoV-2 Infections in a Triad of Primary School Learners (Grades 1–7), Their Parents, and Teachers in KwaZulu-Natal, South Africa: Protocol for a Cross-Sectional and Nested Case-Cohort Study Read more about SARS-CoV-2 Infections in a Triad of Primary School Learners (Grades 1–7), Their Parents, and Teachers in KwaZulu-Natal, South Africa: Protocol for a Cross-Sectional and Nested Case-Cohort Study