As SARS-CoV-2 infects cells in the nasal passages, COVID-19 cases begin to develop. As a result, many experts and researchers believe that nasal sprays may be the most efficient means of infection prevention. Currently, scientists have developed a live, attenuated SARS-CoV-2 vaccine that is administered intravenously. The vaccine produced the strongest immunity in a pre-clinical model when compared to vaccinations given intramuscularly. The results were published in Nature Microbiology.SARS-CoV-2 virus particles (yellow) in endosomes of a severely infected nasal olfactory epithelial cell, as seen in a transmission electron micrograph. Picture taken at the Fort Detrick, Maryland-based NIAID Integrated Research Facility (IRF). Credit: NIAID Transmission electron micrograph of SARS-CoV-2 virus particles (yellow) within endosomes of a heavily infected nasal Olfactory Epithelial.