# Development of a cross-protective common cold coronavirus vaccine

## TL;DR

Researchers developed an mRNA vaccine against OC43 coronavirus that also protects against related coronaviruses in mice.

## Contribution

The vaccine induces cross-protective immunity against multiple coronaviruses within the embecovirus subgenus.

## Key findings

- The OC43 vaccine elicited OC43-specific and cross-reactive immune responses in mice.
- The vaccine protected mice against lethal OC43 and MHV-A59 infections.
- The findings support the feasibility of a single vaccine for broad coronavirus protection.

## Abstract

Common cold coronaviruses, such as OC43 and HKU1, typically cause mild
respiratory infections in healthy people. However, they can lead to severe
illness in high-risk groups, including immunocompromised individuals and
older adults. Currently, there is no clinically approved vaccine to prevent
infection by common cold coronaviruses. Here, we developed an mRNA vaccine
expressing a stabilized spike protein derived from OC43 coronavirus and
tested its efficacy in different challenge models in C57BL/6 mice. This
novel OC43 vaccine elicited OC43-specific immune responses, as well as
cross-reactive immune response against other embecoviruses, including HKU1
and mouse hepatitis virus (MHV-A59). Interestingly, this OC43 vaccine
protected mice not only against a lethal OC43 infection but also against a
distant embecovirus, MHV-A59. These findings provide insights for the
development of common cold coronavirus vaccines, demonstrating their
potential to protect against various coronaviruses.

Human coronaviruses like OC43 cause disease in vulnerable populations,
yet no approved vaccines exist. We developed an mRNA vaccine targeting
the OC43 spike protein that protects mice not only against homologous
OC43 challenges but also against the distantly related embecovirus
MHV-A59. These findings demonstrate the feasibility of a single vaccine
conferring broad protection across multiple coronaviruses within the
same subgenus, advancing strategies for pan-coronavirus vaccine
development.