Bringing some hope to the possibility of a coronavirus vaccine, a new study has found a vaccine for the Middle East Respiratory Syndrome (MERS) virus (a close cousin to SARS-CoV-2) in mice. Researchers from the University of Iowa and the University of Georgia delivered a harmless virus (innocuous parainfluenza virus (PIV5)) carrying the MERS spike protein to mice that were engineered to be susceptible to the MERS coronavirus. All the mice in the study survived the vaccination, which carried a lethal dose of MERS. The results of the study are published in the journal, mBio.
Both MERS and COVID-19 are caused by coronaviruses, but MERS is the deadlier of the two, resulting in death about 33% of the time. COVID-19, however, has infected far more people than MERS, with current confirmed cases exceeding 1.25 million.
When the researchers analyzed the immune responses of the mice given the MERS virus, they found antibodies and protective T cells. The antibody response was weak, so they figured that the protective capability of the vaccine is a result of the increased T cell count in the mouse lungs.
University of Iowa professor of pediatrics, Dr. Paul McCray Jr., says, “Our new study indicates that PIV5 may be a useful vaccine platform for emerging coronavirus diseases, including SARS-CoV-2, the virus causing the ongoing COVID-19 pandemic. Using the same strategy, vaccine candidates based on PIV5 expressing the spike protein of SARS-CoV-2 have been generated. We are planning more studies in animals to test the ability of PIV5-based vaccines in preventing disease caused by SARS-CoV-2."
The researchers believe that PIV5 could also be a vaccine for other respiratory diseases and influenza. It’s encouraging that such a low dose of the vaccine was enough to protect the mice from MERS, so the possibility of being able to create enough vaccine for mass immunization is a real possibility.