A protein-based COVID-19 vaccine candidate that mimics the shape of a virus to trigger a strong antibody response in animals has been developed by scientists. In a cohort study published in the journal ACS Central Science, researchers immunized mice with nanoparticles by displaying multiple copies of “receptor-binding-domain” antigens that mimic SARS-CoV-2, the virus that causes COVID-19. is formed.
Most protein-based vaccines train the immune system to recognize a portion of the receptor-binding-domain, the SARS-CoV-2 spike protein, that the virus uses to enter and infect human cells. The spike protein binds to the ACE-2 receptor on host cell surfaces, which serves as a gateway for virus entry. However, not all vaccines elicit both antibody and T cell responses, both of which are known to be important for long-lasting immunity, the researchers noted. Although the new vaccine still needs to be tested for safety and efficacy in humans, it may have an advantage over mRNA vaccines with respect to wider distribution in resource-limited areas, he said.
Researchers at the University of Chicago, United States, previously developed a vaccine delivery device called polymersomes which are self-assembling, spherical nanoparticles that can contain antigens and adjuvants, and then release them inside immune cells.