A SARS-CoV-2 spike protein subunit vaccine induced humoral and cellular immune responses that protected hamsters against infection and prevented transmission.

Rapid advances in vaccine technology are becoming increasingly important in tackling global health crises caused by respiratory virus infections. While traditional vaccines, primarily administered by intramuscular injection, have proven effective, they often fail to provide the broad upper respiratory tract mucosal immunity, which is urgently needed for first‐line control of respiratory viral infections. Furthermore, traditional intramuscular vaccines may not adequately address the immune escape of emerging virus variants. In contrast, respiratory mucosal vaccines developed using the body's mucosal immune response mechanism can simultaneously establish both systemic and mucosal immunity. This dual action effectively allows the respiratory mucosal immune system to function as the first line of defense, preventing infections at the entry points. This review highlights the efficacy of respiratory mucosal vaccines, including innovative delivery methods such as nasal and oral formulations, in enhancing local and systemic immune barriers. Notably, respiratory mucosal vaccines offer potential advantages in protecting against emerging virus variants and maintaining long‐term and multidimensional immune memory in the upper respiratory tract. In addition, a combination of intramuscular and respiratory mucosal delivery of vaccines largely improves their coverage and effectiveness, providing valuable insights for future vaccine development and public inoculation strategies.

SARS-CoV-2 has been the causative pathogen of the pandemic of COVID-19, resulting in catastrophic health issues globally. It is important to develop human-like animal models for investigating the mechanisms that SARS-CoV-2 uses to infect humans and cause COVID-19. Several studies demonstrated that the non-human primate (NHP) is permissive for SARS-CoV-2 infection to cause typical clinical symptoms including fever, cough, breathing difficulty, and other diagnostic abnormalities such as immunopathogenesis and hyperplastic lesions in the lung. These NHP models have been used for investigating the potential infection route and host immune response to SARS-CoV-2, as well as testing vaccines and drugs. This review aims to summarize the benefits and caveats of NHP models currently available for SARS-CoV-2, and to discuss key topics including model optimization, extended application, and clinical translation.

The pandemics of respiratory viruses pose a worldwide public health problem and bio-safety threat. Therefore, the development of high-throughput and accurate infection models is crucial for elucidating viral pathogenesis and accelerating countermeasures to address the evolving respiratory viruses and the unexpected outbreaks of emerging variants. Compared to traditional 2D cultures, organoids exhibit pronounced intercellular interactions, extracellular matrix signaling, and tissue-specific multicellular cooperation, thereby more accurately recapitulating the in vivo microphysiological environment. However, research involving animal models typically requires prolonged experimental timelines, making it challenging to perform high-throughput screening or rapidly develop therapeutic strategies within the valuable timeframe. Since the outbreak of SARS-CoV-2, organoids have significantly advanced basic virology research and demonstrated potential in replicating the pathological and immunological characteristics in human patients. This review provides a comprehensive summary of the theoretical foundations, methodological framework, and complete procedures for identification and validation in organoid construction, along with their applications in the investigation of various respiratory viruses, such as coronaviruses, the influenza virus, respiratory syncytial virus, and others. Overall, the development of organoids, in conjunction with the integration of interdisciplinary technologies, has significantly advanced our fundamental understanding of the immunopathology process of respiratory viral infections, improved research efficiency, and provided precise tools for translational medical research.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant causes breakthrough infections among convalescent patients and vaccinated populations. However, Omicron does not generate robust cross-protective responses.