The COVID-19 vaccines have proven to protect people from the severe forms of the disease, and now researchers are looking for methods to improve the vaccines even more. A team of researchers from Northwestern Medicine has attempted to upgrade the vaccine by adding a nucleocapsid protein as a new antigen. This improvement is expected to make the immune system react much faster.
“At this point, we’re just trying to figure out ‘What should the 2.0 vaccines be? It seems like adding nucleocapsid to the vaccine renders it more protective, relative to having only the spike,” noted Pablo Penaloza-MacMaster, a microbiology-immunology assistant professor at Northwestern University Feinberg School of Medicine.
The difference between the nucleocapsid protein and the spike protein that is used now in vaccines is that the nucleocapsid protein can be found inside the virus, not outside of it like the spike protein. Moreover, this protein represents a virus component that does not change often, making it easier to be targeted by the new vaccine.
“When a cell gets infected by SARS-CoV-2, you want the T cells to recognize this infected cell as soon as possible. If your T cells can detect one of the early proteins expressed during the coronavirus life cycle, then you will be better able to extinguish the infection from the get-go before the virus starts disseminating exponentially,” added Pablo Penaloza-MacMaster
The new vaccine was tested in mice and results revealed that it protected them against breakthrough infections. However, more research is needed in order to reach conclusions regarding the new potential vaccine. Moreover, researchers have also identified some limitations:
“I’m a little worried to see that the mice had viral loads in the brains because this suggests that perhaps with the current spike-based vaccines, these breakthrough infections could potentially get through to the brain. We don’t know if that’s just in mice or whether it constitutes a general phenomenon. We’re investigating that right now, but a technical challenge is that, due to ethical reasons, we cannot sample brain tissue of vaccinated humans to evaluate breakthrough infection.”