Favorable safety and immunogenicity of a combined quadrivalent influenza and recombinant SARS-CoV-2 vaccine in Sprague-Dawley rats for both primary and booster immunization - Report - MDSpire

Safety and Immunogenic Response of a Novel Combined Quadrivalent Influenza and Recombinant SARS-CoV-2 Vaccine in Sprague-Dawley Rats During Primary and Booster Doses

  • By

  • Jinjin Shao

  • Chengda Zhang

  • Guangbiao She

  • Tian Qin

  • Jinyao Zhang

  • Minxi Fang

  • Dan Zhao

  • Linying Wang

  • Lijuan Xia

  • Qian Yang

  • Lili Zhang

  • Yanling Zhang

  • Siming Zhang

  • Jiahong Wang

  • Zhiqi Xie

  • Yunxiang Chen

  • Ying Chen

  • Enqi Huang

  • Lijiang Zhang

  • July 17, 2026

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Clinical Report: Safety and Immunogenic Response of a Novel Combined Vaccine

Overview

The Flu-CoV2 vaccine was evaluated for safety and immunogenicity in Sprague-Dawley rats. It induced IgG and neutralizing antibody responses against both influenza and SARS-CoV-2.

Background

The dual threat of influenza and SARS-CoV-2 presents challenges to public health, necessitating effective vaccination strategies. Combination vaccines can simplify logistics and improve immunization coverage.

Data Highlights

No severe adverse reactions were reported during the studies.

Key Findings

  • No severe or life-threatening adverse reactions were observed during the studies.
  • Transient injection-site nodules resolved completely.
  • Post-vaccination hematologic and biochemical parameters normalized by the end of the recovery period.
  • The primary regimen induced IgG and neutralizing antibody responses against both viruses.
  • As a booster, the vaccine augmented specific antibody levels in pre-immune models.

Clinical Implications

Further evaluation in clinical settings is warranted to confirm these findings.

Conclusion

The preclinical data support the further development of the Flu-CoV2 vaccine.

Related Resources & Content

  1. The Journal of Infectious Diseases, Phase 3 Study Assessing Lot-to-Lot Consistency of Respiratory Syncytial Virus Prefusion Protein F3 Vaccine and Its Immune Response, Safety, and Reactogenicity When Co-administered With Quadrivalent Influenza Vaccine, 2025
  2. Open Forum Infectious Diseases, A Novel Unadjuvanted Subunit Respiratory Syncytial Virus Prefusion F Vaccine Induces Potent and Differentiated Functional Immune Responses Compared to AS01-Adjuvanted Arexvy in Older Adults, 2025
  3. The Journal of Infectious Diseases, Immune Responses of Antineuraminidase Antibodies in Elderly Individuals Following Sequential Administration of Advanced Influenza Vaccines: A Randomized Controlled Study, 2025
  4. The Journal of Infectious Diseases, Evaluation of Safety and Immune Response of a Prefusion-Stabilized SARS-CoV-2 Spike Subunit Vaccine Using a Second-Generation Molecular Clamp in Adults Aged 18 to 55: Results from a Phase I Randomized, Double-Blind, Active Comparator Trial, 2025
  5. Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices — United States, 2025–26 Influenza Season | MMWR, 2025
  6. Immunogenicity and Safety of Influenza and COVID-19 Multicomponent Vaccine in Adults ≥50 Years: A Randomized Clinical Trial - PMC, 2025
  7. Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices — United States, 2025–26 Influenza Season | MMWR
  8. Immunogenicity and Safety of Influenza and COVID-19 Multicomponent Vaccine in Adults ≥50 Years: A Randomized Clinical Trial - PMC

Original Source(s)

Favorable safety and immunogenicity of a combined quadrivalent influenza and recombinant SARS-CoV-2 vaccine in Sprague-Dawley rats for both primary and booster immunization

  • by Jinjin Shao, Chengda Zhang, Guangbiao She, Tian Qin, Jinyao Zhang, Minxi Fang, Dan Zhao, Linying Wang, Lijuan Xia, Qian Yang, Lili Zhang, Yanling Zhang, Siming Zhang, Jiahong Wang, Zhiqi Xie, Yunxiang Chen, Ying Chen, Enqi Huang, Lijiang Zhang

  • July 17, 2026

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