Even as several safe and effective COVID-19 vaccines are being administered to people worldwide, scientists are still hard at work developing different vaccine strategies that could provide even stronger or longer-lasting immunity against SARS-CoV-2 and its variants. Now, researchers reporting in ACS Central Science have immunized mice with nanoparticles that mimic SARS-CoV-2 by displaying multiple copies of the receptor binding domain (RBD) antigen, showing that the vaccine triggers robust antibody and T cell responses.