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 butdo not prevent virus transmission. Unfortunately, fully vaccinatedindividuals with repeated boosters also get infected, and break-through infections have peak viral loads similar to unvaccinatedindividuals and transmit SARS-CoV-2 in household settings, withor without symptoms (Singanayagam et al., 2022). AI studies ofvaccine-resistant mutations in >2.2 million SARS-CoV-2 genomesshow that the mutation frequency correlates strongly with thevaccination rates in Europe and America and predicts a comple-mentary transmission pathway, vaccine-breakthrough or anti-body-resistant mutations, like those in Omicron (Wanget al., 2021). Amidst the emergence of new SARS-CoV-2 variantslike the omicron strain resistant to current vaccines, with higherrates of transmissibility, it is prudent to consider additionalaffordable measures to minimize viral transmission and infection.