Result for
Topic: Vaccines and Immunity
March 3, 2021
SARS-CoV-2 Antibodies Detected in Human Breast Milk Post-Vaccination
[Pre-print, not peer-reviewed] Significantly elevated levels of SARS-CoV-2 specific IgG and IgA antibodies were observed in breast milk starting 7 days after the initial vaccine dose in a cohort study of six lactating women who had received both doses of either the Pfizer/BioNTech or Moderna vaccines. The authors note that the response following vaccination was…
Increased Resistance of SARS-CoV-2 Variant P.1 to Antibody Neutralization
[Pre-print, not peer-reviewed] Reduced neutralization titers against the P.1 SARS-CoV-2 variant were found in both convalescent plasma (6.5-fold) and plasma from individuals who received an mRNA vaccine (2.2-2.8-fold). The P.1 variant completely resisted neutralization by multiple neutralizing monoclonal antibodies. Using a VSV-based SARS-CoV-2 pseudovirus with all 10 mutations of the P.1 variant, the authors note…
March 2, 2021
REACT-2 Round 5 Increasing Prevalence of SARS-CoV-2 Antibodies Demonstrate Impact of the Second Wave and of Vaccine Roll-out in England
[Pre-print, not peer-reviewed] A nationwide cross-sectional study in the England (n=172,000) conducted between January 26 to February 8, 2021 found that the SARS-CoV-2-specific antibody seroprevalence representative of the national population was 14% overall. This figure included seroprevalence due to both immunization and infection. Seroprevalence in unvaccinated people was highest in London and among members of…
Negligible Impact of SARS-CoV-2 Variants on CD4+ and CD8+ T Cell Reactivity in COVID-19 Exposed Donors and Vaccinees
[Pre-print, not peer-reviewed] Bioinformatic analysis suggests that memory T cells generated either by mild SARS-CoV-2 infection (n=11) or mRNA vaccines will not be affected by currently circulating variants. No significant differences were found in the capacity of CD4+ or CD8+ T cells isolated either from convalescent patients following mild disease or vaccinated individuals to recognize…
Binding and Neutralization Antibody Titers After a Single Vaccine Dose in Health Care Workers Previously Infected With SARS-CoV-2
A single dose of mRNA vaccine (Pfizer or Moderna vaccine) elicited higher antibody and neutralization titers in health care workers (n=59) with previous serology-confirmed SARS-CoV-2 infection compared to healthcare workers who were seronegative at baseline. At 14 days post-vaccination, antibody binding strength to SARS-CoV-2 antigens from participants with both asymptomatic and symptomatic prior infection were…
Long-Term SARS-CoV-2-Specific Immune and Inflammatory Responses Across a Clinically Diverse Cohort of Individuals Recovering from COVID-19
[Pre-print, not peer-reviewed] A longitudinal study in California found that SARS-CoV-2-specific T cell responses remained largely stable up to 9 months following SARS-CoV-2 infection (n=70). Stronger CD4+ T cell responses were associated with initial disease severity as well as neutralizing antibody levels, whereas pre-existing lung disease predicted long-term CD8+ T cell responses. While 36% of…
The Advisory Committee on Immunization Practices’ Interim Recommendation for Use of Janssen COVID-19 Vaccine — United States, February 2021
The Advisory Committee on Immunization Practices (ACIP) issued an interim recommendation for use of the single-dose Johnson & Johnson COVID-19 vaccine in persons at least 18 years. The February 28, 2021 recommendation was based on a transparent evidence-based review of all available data, primarily informed by the interim analysis of the Phase 3 clinical trials…
Evaluation of a SARS-CoV-2 Vaccine NVX-CoV2373 in Younger and Older Adults
[Pre-print, not peer-reviewed] The two-dose Novavax recombinant nanoparticle vaccine candidate “NVX-CoV2373” induced robust IgG-anti-spike protein and neutralizing antibody titers against SARS-CoV-2 in both young and older participants, according to results from a Phase I/II trial (n=1,283). >98% of participants had seroconversion in both age groups fourteen days after the second dose. Reactogenicity was predominantly mild…
Reduced Antibody Cross-Reactivity Following Infection with B.1.1.7 than with Parental SARS-CoV-2 Strains
[Pre-print, not peer-reviewed] Convalescent sera from patients infected with the SARS-CoV-2 B.1.1.7 variant demonstrated reduced activity against reference strains from earlier in the pandemic. Neutralizing activity of sera isolated from patients that had confirmed infection by the SARS-CoV-2 B.1.1.7 variant (n=29) was reduced against a parental reference strain isolated from Wuhan by 3.4-fold. In contrast,…
March 1, 2021
Interpreting Vaccine Efficacy Trial Results for Infection and Transmission
[Pre-print, not peer-reviewed] In simulations of randomized trials to estimate the effect of vaccination on transmission, one dose of the Moderna vaccine reduced the potential for transmission by at least 61%. The analysis suggested that the impact of a given vaccine on viral positivity should be assessed separately in symptomatic individuals and positive test results…
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