Early T Cell and Binding Antibody Responses Are Associated with Covid-19 RNA Vaccine Efficacy Onset

April 15, 2021

Early T Cell and Binding Antibody Responses Are Associated with Covid-19 RNA Vaccine Efficacy Onset

In a cohort of 20 healthcare workers receiving the first dose of the Pfizer-BioNTech vaccine, SARS-CoV-2 spike-specific memory T-cell and binding antibody responses were universally detected prior to the time where vaccine efficacy is first detected in clinical trials (day 12). In contrast, receptor blocking and neutralizing antibodies were not detected on day 7 and…

Neutralizing Activity of Sputnik V Vaccine Sera against SARS-CoV-2 Variants

[Pre-print, not peer-reviewed] Neutralizing antibody activity induced by SARS-CoV-2 adenovirus vector vaccine Sputnik V had geometric mean titers (GMT) that were reduced by 6.8-fold against a pseudovirus bearing B.1.351 spike protein mutations when compared to the prototypic D614G strain. GMT reduction was reduced by 2.8-fold against the pseudovirus with the E484K mutation alone. Among the…

Sera Neutralizing Activities against SARS-CoV-2 and Multiple Variants Six Month after Hospitalization for COVID-19

Neutralizing activity in sera of SARS-CoV-2 infected individuals (n=104) against the variants D614G, B.1.1.7, and P.1 up to 6 months after infection was similar compared to the prototypic strain isolated originally in Wuhan, but was reduced 3-fold against the B.1.351 variant. Similar to other studies, anti-spike and anti-nucleocapsid IgG levels waned over time (2.8% reverted…

April 8, 2021

Humoral and Cellular Immunogenicity of the BNT162b2 MRNA Covid-19 Vaccine in Nursing Home Residents

Nursing home residents who had a prior SARS-CoV-2 infection were more likely than those with no history of infection to have an immunologic response within 1 week of the second dose of the Pfizer-BioNtech vaccine. Among nursing home residents in Belgium, humoral and cellular responses elicited by vaccination with the Pfizer-BioNtech vaccine were detected in…

March 16, 2021

Antibody Response After SARS-CoV-2 Infection and Implications for Immunity

A review of 66 observational studies found that most adults with SARS-CoV-2 infection develop IgM and IgG antibody responses. Among studies measuring IgM antibody responses (n=21 studies), 80% of adults developed responses, peaking at 20 days. Among studies measuring IgG antibody responses (n=24 studies), 95% of adults developed responses, peaking at 25 days and remaining…