Study Uses Flu Virus to Speed Up COVID-19 Antibodies

Researchers at the University of California, Riverside, have developed a vaccine to help speed up the process of making antibodies against SARS-CoV-2 by using preexisting immunity to a separate virus (the influenza virus).

To develop the vaccine, the researchers targeted SARS-CoV-2 as a representative pandemic virus and generated a “fusion protein” vaccine that combines the nucleoprotein from influenza A virus and the receptor-binding domain, or RBD, of the SARS-CoV-2 spike protein. The SARS-CoV-2 virus uses the spike protein to attach to a receptor on the surface of cells — the first step in the infection of the cell by the virus. Antibodies against RBD block the interaction of the spike protein with the receptor, thereby preventing the virus from infecting the cell.

The new vaccine design addresses a long-standing challenge in the field of virology: the delay in developing protective adaptive immunity for emerging viral pathogens. According to the researchers, in any infection, antibodies are made by a type of cell called the B cell. Each B cell produces one antibody against one specific target; only a small subset of B cells, however, can produce antibodies against RBD.

“Any delay in the immune response to SARS-CoV-2 means there is some time when people are left poorly protected against the virus. Our vaccine is designed to get people those protective antibody responses faster, so they are not vulnerable to the coronavirus. This is better protection for everyone. It could be especially valuable for people who still lack immunity to SARS-CoV-2 such as children,” explained Rong Hai, PhD, MSc, associate professor of microbiology and plant pathology at the University of California, Riverside.