COVID-19 classification

For COVID-19 frequently asked inpatient questions, click here
For COVID-19 frequently asked outpatient questions, click here

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] ; Associate Editor(s)-in-Chief: Sabawoon Mirwais, M.B.B.S, M.D.[2]

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of coronavirus disease 2019 (COVID-19), can be categorized into two major types, L, the major type (~70%) and S, the minor type (~30%).

• SARS-CoV-2 viruses, the etiological agents of coronavirus disease 2019 (COVID-19), can be categorized into two major types:^[1]
  • L, the major type (~70%)
  • S, the minor type (~30%)

• One hundred and three SARS-CoV-2 virus strains were studied.^[1]
• One hundred and one of them exhibited complete linkage between the two single nucleotide polymorphisms (SNPs): 72 strains exhibited a “CT” haplotype (defined as L type because T28,144 is in the codon of Leucine) and 29 strains exhibited a “TC” haplotype (defined as S type because C28,144 is in the codon of Serine) at these two sites.