Result for
Tag: antibodies
March 29, 2021
Quantitative SARS-CoV-2 Anti-Spike Responses to Pfizer-BioNTech and Oxford-AstraZeneca Vaccines by Previous Infection Status
[Pre-print, not peer-reviewed] Vaccination with either the Pfizer-BioNTech or Oxford-AstraZeneca vaccines led to detectable anti-spike antibodies in nearly all participants in a study of adult healthcare workers (HCWs) in the UK. 3570/3610 (98.9%) HCWs were seropositive >14 days post-first vaccination and prior to second vaccination, 2706/2720 (99.5%) after Pfizer-BioNTech and 864/890 (97.1%) following Oxford-AstraZeneca vaccines….
March 23, 2021
Association of Age With SARS-CoV-2 Antibody Response
SARS-CoV-2 antibody responses are distinct in different age groups, according to a cross-sectional study of a New York City hospital using 31,426 SARS-CoV-2 antibody test results from pediatric and adult patients. IgG levels were negatively correlated with age in the pediatric population (r = -0.45, P < .001), but moderately positively correlated with age in…
Reduced Neutralization of SARS-CoV-2 B.1.1.7 Variant by Convalescent and Vaccine Sera
The B.1.1.7 variant has a 7-fold higher binding affinity to the angiotensin converting enzyme-2 (ACE2) receptor in human cells than a parent SARS-CoV-2 strain isolated from Wuhan, suggesting a mechanism for the rapid emergence of this variant. Serum from individuals vaccinated with either the Pfizer-BioNTech or the Oxford-AstraZeneca and serum recovered from infection with the…
March 12, 2021
Estimated Half-Life of SARS-CoV-2 Anti-Spike Antibodies More than Double the Half-Life of Anti-Nucleocapsid Antibodies in Healthcare Workers
Among healthcare-workers (HCWs) (n=118) who had a previous SARS-CoV-2 infection, 92% were still positive for anti-spike (S) antibodies compared to only 18% for IgG anti-nucleocapsid (N) antibodies after 7-10 months. At 1-3 months, 98% of HCWs were positive for anti-S antibodies compared to 85.6% anti-N antibodies. The mean half-life for anti-S antibodies was 19 days…
March 10, 2021
Previous SARS-CoV-2 Infection Increases B.1.1.7 Cross-Neutralization by Vaccinated Individuals
[Pre-print, not peer-reviewed] Sera from individuals who had been previously infected with SARS-CoV-2 and received the vaccine showed equivalent neutralizing responses against the B.1.1.7 variant and original virus strain, while sera from vaccinated individuals with no prior infection showed reduced neutralization against B.1.1.7. Neutralizing activity was assessed against pseudoviruses bearing the spike protein from the…
The Plasmablast Response to SARS-CoV-2 MRNA Vaccination Is Dominated by Non-Neutralizing Antibodies That Target Both the NTD and the RBD
[Pre-print, not peer-reviewed] A study of vaccine-induced polyclonal antibodies and monoclonal antibodies (mAbs) from subjects who received SARS-CoV-2 mRNA vaccines found that polyclonal antibody responses were robust and comparable to or exceeded those observed after natural infection. However, most vaccine-induced mAbs did not demonstrate neutralizing activity. Neutralizing activity of N-terminal domain (NTD) mAbs, but not…
March 9, 2021
COVID-19 Vaccine Response in Pregnant and Lactating Women a Cohort Study
[Pre-print, not peer-reviewed] The Pfizer-BioNTech and Moderna vaccines elicited similar immune responses among pregnant (n=84) and lactating (n=31) women compared to non-pregnant reproductive-age women (n=16). All vaccine-induced SARS-CoV-2-specific antibody titers were higher compared to titers from a group of pregnant women (n=37) that had SARS-CoV-2 infection 4-12 weeks prior. Vaccine-induced antibodies were detected in all…
Serological Evidence of Human Infection with SARS-CoV-2: A Systematic Review and Meta-Analysis
Seroprevalence of SARS-CoV-2-specific antibodies varied dramatically across WHO regions, according to a systematic review and meta-analysis including over 5 million participants from 400 serosurveys. The Southeast Asia region had the highest seroprevalence (20%), while the Western Pacific region, including Australia and New Zealand, had the lowest (1.7%). In a subset of serosurveys with higher quality…
March 5, 2021
SARS-CoV-2 Variant with Higher Affinity to ACE2 Shows Reduced Sera Neutralization Susceptibility
[Pre-print, not peer-reviewed] An in vitro study of newly-emerging SARS-CoV-2 mutations in the receptor binding domain (RBD) of the viral spike protein found in the P.1 variant (first described in Brazil) demonstrated increased angiotensin-converting enzyme 2 (ACE2) affinity for the mutant RBD and reduced neutralization ability of immune sera induced from prior strains. RBD mutations…
Age-Dependent Immune Response to the BioNtech-Pfizer BNT162b2 COVID-19 Vaccination
[Pre-print, not peer-reviewed] Among 176 participants receiving two doses of the Pfizer-BioNTech vaccine in a cohort study in Germany, participants aged >80 years had lower SARS-CoV-2 specific IgG antibody titers and neutralizing titers compared to participants aged <60 years after each dose. While the IgG titer increase between the first and second dose was larger…
Previous page Next page