Result for
Tag: vaccines
April 7, 2021
Antibody Persistence through 6 Months after the Second Dose of MRNA-1273 Vaccine for Covid-19
Neutralizing antibody activity elicited by the Moderna vaccine remained high 6 months after the second dose in all 33 adults in an ongoing phase 1 trial, as measured by 3 different serologic assays. Binding antibody half-life estimates after day 43 for all the participants were 52 days when calculated via an exponential decay model (assumes…
April 6, 2021
COVID-19 MRNA Vaccines Drive Differential Fc-Functional Profiles in Pregnant Lactating and Non-Pregnant Women
[Pre-print, not peer-reviewed] The antibody response induced by mRNA vaccines (Moderna and Pfizer-BioNTech) after the first dose was lower among pregnant (n=84) and lactating (n=31) women compared to non-pregnant age-matched controls (n=16), but after the second dose no significant differences were observed. Differences in antibody response after the first dose related to lower antibody titers…
April 2, 2021
SARS-CoV-2 Immune Evasion by Variant B.1.427B.1.429
[Pre-print, not peer-reviewed] The SARS-CoV-2 variant CAL.20C (also known as B.1.427/B.1.429, with key mutations S13I, W152C and L452R), which was first described in California, has plasma neutralizing activity that is 3- to 4-fold lower in individuals fully vaccinated with the Moderna or Pfizer-BioNTech vaccines compared to the wild-type SARS-CoV-2 strain. Reduction in neutralizing activity among…
Interim Report Safety And Immunogenicity Of An Inactivated Vaccine Against Sars-Cov-2 In Healthy Chilean Adults In A Phase 3 Clinical Trial
[Pre-print, not peer-reviewed] Interim results for the phase 3 clinical trial (n=397) of the SARS-CoV-2 inactivated-virus vaccine CoronaVac (SinoVac BioTech) conducted in Chile indicate the vaccine is safe to use and induces neutralizing antibody production against the SARS-CoV-2 spike protein. Among participants receiving two doses of the vaccine (n=239) or placebo (n=80) 2 weeks apart,…
March 31, 2021
Initial Report of Decreased SARS-CoV-2 Viral Load after Inoculation with the BNT162b2 Vaccine
In a real-world analysis of data from individuals in Israel who tested positive for SARS-CoV-2 after receiving the first dose of the Pfizer-BioNTech vaccination (n=4,938), viral load was substantially lower (2.8 to 4.5-fold lower) for infections occurring 12-37 days after the first dose compared to individuals who had not been vaccinated. Cycle of threshold (Ct)…
Efficacy of ChAdOx1 NCoV-19 (AZD1222) Vaccine against SARS-CoV-2 Variant of Concern 202012/01 (B.1.1.7): An Exploratory Analysis of a Randomised Controlled Trial
Post-hoc analysis of the Oxford-AstraZeneca vaccine indicated that clinical vaccine efficacy against symptomatic, PCR-positive infection was 70.4% for the B.1.1.7 variant and 81.5% for non-B.1.1.7 lineages (not including the B.1.351 variant). Neutralization activity via vaccine-induced antibodies in vitro was also lower against the B.1.1.7 variant (geometric mean ratio 8.9). Participants 18 and older in efficacy cohorts…
Pfizer-BioNTech Announce Positive Topline Results of Pivotal COVID-19 Vaccine Study in Adolescents.
[Press release, not peer-reviewed] According to a press release from Pfizer, the Pfizer-BioNTech vaccine showed 100% efficacy against COVID-19 among adolescents (n=2,260) aged 12 to 15 years old in the US without prior history of infection. 18 cases of COVID-19 were observed in the placebo group, and none in the vaccinated group. The vaccine also…
March 25, 2021
Antibody Responses after a Single Dose of SARS-CoV-2 mRNA Vaccine
Among healthcare workers who received a single dose of the Pfizer-BioNTech vaccine, those who had SARS-CoV-2 infection 30-60 days prior to vaccination (n=36) had significantly higher antibody levels and higher levels of antibodies with neutralizing characteristics at 3 weeks post-vaccination than individuals with no prior infection (n=152). After the first vaccine dose, both previously infected…
BNT162b2 MRNA Covid-19 Vaccine Effectiveness among Health Care Workers
Weekly incidence of COVID-19 among healthcare workers (HCWs) in a two-campus medical center in Jerusalem steadily declined after commencement of two-dose vaccinations with the Pfizer-BioNTech vaccine in December 2020. Decline in incidence occurred despite a surge of the B.1.1.7 variant (up to 80% of cases) within the community. Benenson et al. (Mar 23, 2021). BNT162b2 MRNA…
March 23, 2021
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…
Previous page Next page