Neutralizing Antibody Activity to SARS-CoV-2 Delta (B.1.617.2) and Omicron (B.1.1.529) After One and Two Doses of BNT162b2 Vaccine in Infection-Naïve and Previously-Infected Individuals
Previous reports demonstrated that SARS-CoV-2 binding IgG did not increase significantly between first and second doses of the BNT162b2 vaccine in previously-infected individuals. We tested neutralizing antibodies (nAb) against SARS-CoV-2 Delta and Omicron variants post first and second doses of BNT162b2 in infection-naïve and previously-infected individuals. Delta, but not Omicron, nAb significantly increased from first to second dose in both groups of individuals.
A neutralizing antibody target in early HIV-1 infection was recapitulated in rhesus macaques immunized with the transmitted/founder envelope sequence
Transmitted/founder (T/F) HIV-1 envelope proteins (Envs) from infected individuals that developed neutralization breadth are likely to possess inherent features desirable for vaccine immunogen design. To explore this premise, we conducted an immunization study in rhesus macaques (RM) using T/F Env sequences from two human subjects, one of whom developed potent and broad neutralizing antibodies (Z1800M) while the other developed little to no neutralizing antibody responses (R66M) during HIV-1 infection.