Result for
Topic: Vaccines and Immunity
March 1, 2021
Reanalysis of the Pfizer MRNA BNT162b2 SARS-CoV-2 Vaccine Data Fails to Find Any Increased Efficacy Following the Boost Implications for Vaccination Policy and Our Understanding of the Mode of Action
[Pre-print, not peer-reviewed] A study exploring the timing of protection conferred by the Pfizer/BioNTech vaccine indicated that the vaccine was effective beginning 11 days following the first dose, suggesting that vaccine protection precedes the full development of neutralizing antibodies. In addition, efficacy did not increase following the second dose (compared to the period between day…
Antibody Response to First BNT162b2 Dose in Previously SARS-CoV-2-Infected Individuals
A nested case-control study of 51 health care workers found that anti-S titers 19-29 days after the first dose of the Pfizer/BioNTech vaccine were comparable to peak titers after natural infection. Among those with a previous SARS-CoV-2 infection, vaccination increased anti-S titers more than 140-fold from peak pre-vaccine levels. Prior infection was determined by positive…
Effect of Previous SARS-CoV-2 Infection on Humoral and T-Cell Responses to Single-Dose BNT162b2 Vaccine
Individuals with prior SARS-CoV-2 infection generated strong humoral and cellular responses following a single dose of the Pfizer/BioNTech vaccine, according to an analysis of specimens from healthcare workers in the UK (n = 72). Individuals who had not been previously infected showed weaker T-cell responses and generated lower neutralizing antibody titers (median 615.1 vs. 16353…
February 26, 2021
Obesity May Hamper SARS-CoV-2 Vaccine Immunogenicity
[pre-print; not peer-reviewed] Antibody titers two weeks after receiving a second dose of the Pfizer-BioNTech vaccine were lower in obese healthcare workers (BMI >30), after adjusting for age. 99.5% of the 248 participants developed a humoral immune response after vaccination, and antibody titers were higher in younger people and in women. The authors note that…
SARS-CoV-2 Viremia Is Associated with Distinct Proteomic Pathways and Predicts COVID-19 Outcomes
[pre-print; not peer-reviewed] Levels of plasma SARS-CoV-2 viremia at the time of presentation to a hospital’s emergency department predicted both disease severity and mortality within 28 days. Viremia (defined as presence of SARS-CoV-2 RNA in plasma samples) was present in around 40% of participants and was associated with a dose-dependent effect on clinical outcome. Li…
Seasonal Human Coronavirus Antibodies Are Boosted upon SARS-CoV-2 Infection but Not Associated with Protection
Cross reactive antibodies generated by pre-pandemic human coronavirus (hCoV) infections are common but are not associated with protection against infection or poor clinical outcomes after infection with SARS-CoV-2. Using samples from a pre-pandemic biobank, 4% of pre-pandemic sera contained antibodies that bound the full-length spike from SARS-CoV-2 and 16% of samples contained antibodies capable of…
Reduction in COVID-19 Patients Requiring Mechanical Ventilation Following Implementation of a National COVID-19 Vaccination Program — Israel, December 2020–February 2021
In Israel, the ratio of COVID-19 patients over the age of 70 requiring mechanical ventilation declined 67% compared to those under 50 from October–December 2020 to February 2021 after a national immunization program resulting in a 2-dose vaccination coverage of 84% among people over the age of 70. The authors suggest that this provides preliminary…
February 25, 2021
Evidence of Escape of SARS-CoV-2 Variant B.1.351 from Natural and Vaccine Induced Sera
Neutralizing antibody titers were lower in assays against the SARS-CoV-2 B.1.351 variant compared to an early isolate from Wuhan across several sample sources. The geometric mean neutralizing titers were lower by 13.3-fold in convalescent plasma from patients infected during the first wave in the UK (n=34), by 3.1-fold in sera from patients infected with the…
Association of SARS-CoV-2 Seropositive Antibody Test With Risk of Future Infection
In a cohort study of over 3.2 million US patients with a SARS-CoV-2 antibody test result (88% negative), the ratio of seropositive to seronegative patients with a positive SARS-CoV-2 nucleic acid amplification test (NAAT) decreased from 3% within 30 days of the antibody test to 0.1% after at least 90 days following the antibody test….
BNT162b2 MRNA Covid-19 Vaccine in a Nationwide Mass Vaccination Setting
In an observational study of the mass vaccination campaigns in Israel, real world effectiveness of the Pfizer vaccine 7 or more days after the second dose was 92% for documented SARS-CoV-2 infection, 94% for symptomatic infection, 87% for hospitalization, and 92% for severe disease. The study included 596,618 individuals matched to unvaccinated controls in a…
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