Oral booster vaccine antigen—Expression of full-length native SARS-CoV-2 spike protein in lettuce chloroplasts

Current vaccines continue to save lives during the pandemic but do not prevent virus transmission. Unfortunately, fully vaccinated individuals with repeated boosters also get infected, and breakthrough infections have peak viral loads similar to unvaccinated individuals and transmit SARS-CoV-2 in household settings, with or without symptoms (Singanayagam et al., 2022). AI studies of vaccine-resistant mutations in >2.2 million SARS-CoV-2 genomes show that the mutation frequency correlates strongly with the vaccination rates in Europe and America and predicts a complementary transmission pathway, vaccine-breakthrough or antibody-resistant mutations, like those in Omicron (Wang et al., 2021). Amidst the emergence of new SARS-CoV-2 variants like the omicron strain resistant to current vaccines, with higher rates of transmissibility, it is prudent to consider additional affordable measures to minimize viral transmission and infection.