Media advice
Wednesday 3 February 2021
What
An experimental single-dose intranasal influenza vaccine was safe and elicited a lasting immune response when tested in a phase 1 study conducted in the Journal of Clinical Examination. The research vaccine, called Ad4-H5-VTN, is a recombinant, replicating adenovirus vaccine designed to stimulate antibodies to hemagglutinin, a protein found on the surface of influenza viruses that attach to human cells.
The research vaccine was developed by Emergent Biosolutions Inc., (Gaithersburg, Maryland). It was administered intranasally (28 participants in the study), as an oral capsule (10 participants) and via a tonsil stick (25 participants) to healthy men and non-pregnant women aged 18 to 49 years.
The participants who received the vaccine intranasally or via the tonsil swab showed a significantly higher H5-specific neutralizing antibody levels compared to the group that received the vaccine capsule orally. The participants who received the intranasal vaccine shed viral DNA for two to four weeks, but viruses could only be cultured for one day. Participants had evidence of H5-specific CD4 + and CD8 + T cell responses. In addition, volunteers who received the intranasal vaccine had high levels of serum neutralizing antibodies at 26 weeks after vaccination, and this level was unchanged at three to five years after a single intranasal dose of the vaccine. The duration of viral shedding correlated with a large degree of neutralizing antibody response at week 26. In addition, the intranasal vaccine elicited a mucosal antibody response in the nose, mouth, and rectum.
The study authors speculate that replication-capable vector vaccines may have advantages over other types of vaccines because they can express viral proteins at higher levels and over time. Furthermore, this type of vaccine elicits a mucosal immune response that is critical for the transmission of viruses that infect mucosal tissues.
According to the authors, the vaccine platform may be highly adaptable for use against other viruses, including HIV and SARS-CoV-2.
Article
K Matsuda et al. A competent vaccine implemented by adenovirus causes lasting systemic and mucosal immunity. Journal of Clinical Examination DOI: doi.org/10.1172/JCI140794.
Who
Mark Connors, MD, Head of the HIV-Specific Immunity Division in NIAID’s Immunoregulatory Laboratory and Principal Investigator for the Phase 1 Study, is available for interviews.
NIAID conducts and supports research – at NIH, across the United States and worldwide – to study the causes of infectious and immune-mediated diseases, and to develop better ways to prevent, diagnose, and treat these diseases. News reports, fact sheets and other NIAID related material are available on the NIAID website.
About the National Institutes of Health (NIH):
NIH, the country’s medical research agency, contains 27 institutes and centers and is part of the U.S. Department of Health and Human Services. NIH is the primary federal agency that conducts and supports basic, clinical, and translational medical research, investigating the causes, treatments, and drugs for common and rare diseases. Visit www.nih.gov for more information on NIH and its programs.
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