Abstract
Influenza is one of the major threats to public health. Current influenza vaccines cannot provide effective protection against drifted or shifted influenza strains. Researchers have considered two important strategies to develop novel influenza vaccines with improved immunogenicity and broader protective efficacy. One is applying fewer variable viral antigens, such as the haemagglutinin stalk domain. The other is including adjuvants in vaccine formulations. Adjuvants are promising and helpful boosters to promote more rapid and stronger immune responses with a dose-sparing effect. However, few adjuvants are currently licensed for human influenza vaccines, although many potential candidates are in different trials. While many advantages have been observed using adjuvants in influenza vaccine formulations, an improved understanding of the mechanisms underlying viral infection and vaccination-induced immune responses will help to develop new adjuvant candidates. In this review, we summarize the works related to adjuvants in influenza vaccine research that have been used in our studies and other laboratories. The review will provide perspectives for the utilization of adjuvants in developing next-generation and universal influenza vaccines.
Highlights
Influenza epidemics are a severe public health issue each year
We demonstrated that microneedle patch (MNP)-based boosting immunizations with the 4M2e-FliC could rapidly broaden influenza-vaccine-induced immunity [43]
We found that a glycolipid (GPI)-anchoring GIFT4 enhanced the immunogenicity of HIV virus-like particles (VLPs) [82]
Summary
Influenza epidemics are a severe public health issue each year. During the 2019–2020 influenza season in the United States, about 38 million illnesses, 400,000 hospitalizations, and 22,000 deaths were associated with influenza [1]. A panel of methods was developed for viral isolation, identification, and sequencing, allowing scientists to rapidly identify mutant strains when a mismatch occurs at the early stage of an influenza outbreak. The well-known conserved antigens include the head-removed hemagglutinin stalk domain (hrHA), neuraminidase (NA), matrix protein 2 (M2), and T cell epitopes resident in influenza internal proteins (such as nucleoprotein (NP) and matrix protein 1 (M1) Some combinations of these antigens have proven to provide cross-protection against different virus challenges in laboratory animals. Through a deep understanding of the immunological mechanisms underlying natural influenza infection for immunity generation and memory, safe and effective adjuvants will be discovered and applied to develop universal influenza vaccines. We will focus on the novel adjuvants that might have potent effects in bridging innate and adaptive immune responses and discuss the delivery strategies and routes used to improve influenza vaccine outcomes
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
