A SARS-CoV-2 and influenza double hit vaccine based on RBD-conjugated inactivated influenza A virus

Sci Adv. 2023 Jun 23;9(25):eabo4100. doi: 10.1126/sciadv.abo4100. Epub 2023 Jun 23.

Abstract

The circulating flu viruses merging with the ongoing COVID-19 pandemic raises a more severe threat that promotes the infectivity of SARS-CoV-2 associated with higher mortality rates. Here, we conjugated recombinant receptor binding domain (RBD) of SARS-CoV-2 spike protein onto inactivated influenza A virus (Flu) to develop a SARS-CoV-2 virus-like particle (VLP) vaccine with two-hit protection. This double-hit vaccine (Flu-RBD) not only induced protective immunities against SARS-CoV-2 but also remained functional as a flu vaccine. The Flu core improved the retention and distribution of Flu-RBD vaccine in the draining lymph nodes, with enhanced immunogenicity. In a hamster model of live SARS-CoV-2 infection, two doses of Flu-RBD efficiently protected animals against viral infection. Furthermore, Flu-RBD VLP elicited a strong neutralization activity against both SARS-CoV-2 Delta pseudovirus and wild-type influenza A H1N1 inactivated virus in mice. Overall, the Flu-RBD VLP vaccine is a promising candidate for combating COVID-19, influenza A, and coinfection.

MeSH terms

  • Animals
  • COVID-19 Vaccines
  • COVID-19* / prevention & control
  • Cricetinae
  • Humans
  • Influenza A Virus, H1N1 Subtype*
  • Influenza A virus*
  • Influenza Vaccines*
  • Influenza, Human*
  • Mice
  • Pandemics
  • SARS-CoV-2

Substances

  • Influenza Vaccines
  • spike protein, SARS-CoV-2
  • COVID-19 Vaccines