98%
921
2 minutes
20
Neutralizing antibodies (NAbs), and their concentration in sera of convalescents and vaccinees are a correlate of protection from COVID-19. The antibody concentrations in clinical samples that neutralize SARS-CoV-2 are difficult and very cumbersome to assess with conventional virus neutralization tests (cVNTs), which require work with the infectious virus and biosafety level 3 containment precautions. Alternative virus neutralization tests currently in use are mostly surrogate tests based on direct or competitive enzyme immunoassays or use viral vectors with the spike protein as the single structural component of SARS-CoV-2. To overcome these obstacles, we developed a virus-free, safe and very fast (4.5 h) diagnostic test based on engineered yet authentic SARS-CoV-2 virus-like-particles (VLPs). They share all features of the original SARS-CoV-2 but lack the viral RNA genome and thus are non-infectious. NAbs induced by infection or vaccination, but also potentially neutralizing monoclonal antibodies can be reliably quantified and assessed with ease and within hours with our test, because they interfere and block the ACE2-mediated uptake of VLPs by recipient cells. Results from the VLP neutralization test (VLPNT) showed excellent specificity and sensitivity and correlated very well with a cVNT using fully infectious SARS-CoV-2. The results also demonstrated the reduced neutralizing capacity of COVID-19 vaccinee sera against variants of concern of SARS-CoV-2 including omicron B.1.1.529, BA.1.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9645495 | PMC |
http://dx.doi.org/10.1093/pnasnexus/pgac045 | DOI Listing |
Arch Microbiol
September 2025
Department of Infectious Disease, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, No. 639, Zhizaoju Road, Huangpu District, Shanghai, 200011, China.
Highly pathogenic avian influenza (HPAI) H5N1 virus poses a continuing global public health threat due to its outbreaks in poultry farms and zoonotic transmission from birds to humans. In the quest of effective therapeutics against H5N1 infection, antibodies with broad neutralizing activity have attracted significant attention. In this study, we employed a phage display technique to select and identify VHH antibodies with specific neutralizing activity against H5N1 hemagglutinin (HA) from an immune llama-derived antibody library.
View Article and Find Full Text PDFAdv Sci (Weinh)
September 2025
College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, China.
Porcine reproductive and respiratory syndrome virus (PRRSV) imposes substantial economic losses on global swine production. While modified live vaccines remain the primary prevention tool, their efficacy is compromised by the genetic variability of PRRSV. This study developed a broadly neutralizing monoclonal antibody (mAb) that targets a conserved viral epitope as an alternative therapeutic strategy.
View Article and Find Full Text PDFBlood Vessel Thromb Hemost
August 2025
Divsion of Hematology, Oncology & Bone Marrow Transplantation, Department of Pediatrics, Children's Mercy Hospital, Kansas City, MO.
Clotting factor concentrate (CFC), used to treat and prevent bleeding in hemophilia, is rendered ineffective if clotting factor neutralizing antibodies (inhibitors) develop. Inhibitors occur most often in children, early in treatment. The American Thrombosis and Hemostasis Network (ATHN) 8: US Cohort Study of Previously Untreated Patients (PUPs) with Congenital Hemophilia, conducted in children born in 2010 to 2020 with severe or moderate hemophilia, was designed to determine the percentage of participants who developed a confirmed, clinically significant inhibitor within the first 50 CFC exposure days (EDs).
View Article and Find Full Text PDFCurr HIV Res
August 2025
U.S. Mil-itary HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA.
Reports of HIV-1-specific broadly neutralizing monoclonal antibodies (bNAbs) medi-ating a potential 'vaccinal effect' implicate passively transferred bNAbs in promoting endoge-nous anti-HIV-1 immune responses. To date, three clinical trials have reported either increased anti-HIV-1 neutralizing antibodies or T cell responses following bNAb administration to people living with HIV. Despite strong enthusiasm for this hypothesis, motivated in large part by its potential application to HIV-1 therapeutic strategies, the mechanism(s) underlying a vaccinal ef-fect remain unclear.
View Article and Find Full Text PDFCurr HIV Res
September 2025
Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA.
Newborns represent only 1% of the population. Yet, HIV vertical transmissions represent 10% of all new infections globally, even though antiretroviral therapy (ART) has been shown to reduce the risk of vertical transmission to less than 2%. While vaccines still represent the most efficient and cost-effective intervention to eradicate new infections, HIV immunogens that can effectively elicit broad-spectrum protection are still at least a decade away.
View Article and Find Full Text PDF