Advice to the media
Wednesday, February 3, 2021
What
An experimental single-dose intranasal flu vaccine was safe and produced a lasting immune response when tested in a phase 1 study published in the Journal of Clinical Research. The research vaccine, called Ad4-H5-VTN, is a recombinant vaccine against replicating adenovirus, designed to stimulate antibodies to hemagglutinin, a protein found on the surface of flu viruses that binds to human cells.
The research vaccine was developed by Emergent Biosolutions Inc., (Gaithersburg, Maryland). It was administered intranasally (28 study participants), as an oral capsule (10 participants) and by an amygdala swab (25 participants) to healthy men and non-pregnant women aged 18 to 49 years.
Participants who received the vaccine intranasally or via an amygdala swab showed significantly higher levels of H5-specific neutralizing antibodies than the group that received the vaccine capsule orally. Participants who received the intranasal vaccine released viral DNA for two to four weeks, but the virus could be cultured for only one day. Participants had H5-specific CD4 + and CD8 + T cell response tests. In addition, volunteers who received the intranasal vaccine had high levels of serum neutralizing antibodies at 26 weeks after vaccination, and this level changed at three to five years after a single intranasal dose of the vaccine. . The duration of the viral outbreak correlated with a high magnitude of neutralizing antibody response at week 26. In addition, the intranasal vaccine induced a mucosal antibody response in the nose, mouth, and rectum.
The study authors speculate that vector vaccines competent for replication may have advantages over other types of vaccines, as they may express viral proteins at higher levels and for longer durations. In addition, this type of vaccine induces a mucosal immune response that is critical in limiting the transmission of viruses that infect mucosal tissues.
According to the authors, the vaccine platform could be highly adaptable for use against other viruses, including HIV and SARS-CoV-2.
Article
K Matsuda et al. A flu vaccine with replication-competent adenovirus vector induces lasting systemic immunity and mucosa. Journal of Clinical Research DOI: doi.org/10.1172/JCI140794.
WHO
Mark Connors, MD, head of the HIV-specific immunity section at NIAID’s immunoregulation laboratory and principal investigator of the Phase 1 study, is available for interviews.
NIAID conducts and supports research, at NIH, throughout the United States and around the world, to study the causes of infectious and immune diseases and to develop better means to prevent, diagnose, and treat these diseases. Press releases, fact sheets and other NIAID-related materials are available on the NIAID website.
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