Neutralizing antibodies from early cases of SARS-CoV-2 infection offer cross-protection against the SARS-CoV-2 D614G variant

The emergence of a SARS-CoV-2 variant with a point mutation in the spike (S) protein, D614G, has taken precedence over the original Wuhan isolate by May 2020. With an increased infection and transmission rate, it is imperative to determine whether antibodies induced against the D614 isolate may cross-neutralize against the G614 variant. In this report, profiling of the anti-SARS-CoV-2 humoral immunity reveals similar neutralization profiles against both S protein variants, albeit waning neutralizing antibody capacity at the later phase of infection. These findings provide further insights towards the validity of current immune-based interventions. IMPORTANCE Random mutations in the viral genome is a naturally occurring event that may lead to enhanced viral fitness and immunological resistance, while heavily impacting the validity of licensed therapeutics. A single point mutation from aspartic acid (D) to glycine (G) at position 614 of the SARS-CoV-2 spike (S) protein, termed D614G, has garnered global attention due to the observed increase in transmissibility and infection rate. Given that a majority of the developing antibody-mediated therapies and serological assays are based on the S antigen of the original Wuhan reference sequence, it is crucial to determine if humoral immunity acquired from the original SARS-CoV-2 isolate is able to induce cross-detection and cross-protection against the novel prevailing D614G variant.