Result for
Topic: Vaccines and Immunity
November 18, 2020
New Pfizer Results: Coronavirus Vaccine Is Safe and 95% Effective
[Press release, not peer-reviewed] A pre-specified analysis of the Pfrizer mRNA vaccine suggested that the vaccine was 95% efficacious and prevented severe disease, according to a company press-release. 162 cases out of 170 cases of COVID-19 disease occurred in the placebo arm, with 9 out of 10 severe cases occurring in the placebo arm. Similar…
November 17, 2020
Immunological Memory to SARS-CoV-2 Assessed for Greater than Six Months after Infection
[Pre-print, not peer reviewed] Different components of the immune memory against SARS-CoV-2 exhibited distinct kinetics over time in a cross-sectional study of 185 recovered COVID-19 cases. Spike IgG levels were relatively stable over >6 months, memory B cells were more abundant at 6 months than at 1 month, and CD8+ and CD4+ T cells declined…
Estimating the Cumulative Incidence of SARS-CoV-2 Infection and the Infection Fatality Ratio in Light of Waning Antibodies
[Pre-print, not peer reviewed] The cumulative incidence of SARS-CoV-2 infection may be underestimated by using cross-sectional data from serology tests without adjusting for waning antibodies. By estimating the average time from seroconversion to seroreversion and combining with population-level cross sectional data, Shioda et al. calculated the cumulative incidence to be 27% in New York City…
November 16, 2020
Sex Differences in the Decline of Neutralizing Antibodies to SARS-CoV-2
[Pre-print, not peer-reviewed] A longitudinal study of sera from 308 SARS-CoV-2 RT-PCR positive individuals found that males exhibited a faster decline in anti-S and neutralizing antibodies than females, suggesting that the duration of protection may differ by sex. Higher levels of antibodies were observed one month after symptom onset among males, people over age 50,…
Moderna’s COVID-19 Vaccine Candidate Meets its Primary Efficacy Endpoint in the First Interim Analysis of the Phase 3 COVE Study
[Press release, not peer-reviewed] The COVID-19 vaccine candidate (mRNA-1273) from Moderna demonstrated 94.5% efficacy in Phase 3 of the COVE study, which is evaluating the effect of the vaccine on disease prevention and severity. Interim results were based on 95 COVID-19 cases, 90 of which were reported in the placebo group and 5 in the…
November 13, 2020
Diagnosis and Tracking of Past SARS-CoV-2 Infection in a Large Study of Vo’ Italy Through T-Cell Receptor Sequencing
[Pre-print, not peer-reviewed] The presence of T-cells reactive to SARS-CoV-2 was found to be a strong indicator of past SARS-CoV-2 infection. In a large population study (n = 2,200) in Italy that included 70 individuals with PCR-confirmed SARS-CoV-2 infection, blood samples taken 60 days after PCR diagnosis indicated that 97% of the people with PCR-confirmed…
November 12, 2020
Quick COVID-19 Healers Sustain Anti-SARS-CoV-2 Antibody Production
Analysis of longitudinal antibody responses of 76 COVID-19 patients followed for approximately 100 days showed that while anti-spike protein IgG levels declined rapidly for most individuals, those with sustained (and in some instances increased) anti-spike protein IgG levels experienced shorter disease course (median 10 vs. 16 days). Being an antibody “sustainer” also predicted persistent neutralizing…
Seasonal Human Coronavirus Antibodies Are Boosted upon SARS-CoV-2 Infection but Not Associated with Protection
[Pre-print, not peer reviewed] An analysis suggests that prior infection with human coronaviruses other than SARS-CoV-2 is not associated with protection from SARS-CoV-2 infection. The authors found no significant differences in the levels of pre-pandemic human coronavirus antibodies cross-reactive to SARS-CoV-2 proteins between a cohort of people eventually infected with SARS-CoV-2 (n=251) and a matched…
November 10, 2020
Longitudinal Characterization of the IgM and IgG Humoral Response in Symptomatic COVID-19 Patients Using the Abbott Architect
A longitudinal analysis of 1,349 serum samples collected up to 168 days post symptom onset from 427 individuals with PCR-confirmed COVID-19 found that IgM seroconversion occurs earlier than IgG, but that IgM levels decline to a greater extent over time. The median duration of time for IgM seroconversion was 10 days, but seroprevalence declined steadily…
November 9, 2020
Preexisting and de Novo Humoral Immunity to SARS-CoV-2 in Humans
Using flow cytometry, SARS-CoV-2 spike glycoprotein (S)-reactive IgG antibodies were detected in 6 of 65 SARS-CoV-2-uninfected individuals (5 with RT-qPCR-confirmed seasonal human coronaviruses [HCoVs] infection and 1 without recent HCoV infection). The authors conclude that this may suggest the presence of cross-reactive immunological memory from preexisting infection rather than de novo immunity. Ng et al. (Nov…
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