RT Journal Article SR Electronic T1 The role of cross-reactive immunity to emerging coronaviruses JF Saudi Medical Journal JO Saudi Med J FD Prince Sultan Military Medical City SP 965 OP 972 DO 10.15537/smj.2023.44.10.20230375 VO 44 IS 10 A1 Alturaiki, Wael YR 2023 UL http://smj.org.sa/content/44/10/965.abstract AB Host immune response to coronaviruses and the role of cross-reactivity immunity among different coronaviruses are crucial for understanding and combating the continuing COVID-19 outbreak and potential subsequent pandemics. This review paper explores how previous exposure to common cold coronaviruses and more pathogenic coronaviruses may elicit a protective immune response against SARS-CoV-2 infection, and discusses the challenges posed by some variants of concern that may escape current vaccines. It also highlights the need for a mucosal universal vaccine that can induce long-term protection against current and emerging coronaviruses by leveraging cross-reactive immunity. We propose a novel mucosal universal vaccine that consists of cross-reactive antigenic peptides with highly conserved epitopes among coronaviruses, conjugated with an immunostimulant adjuvant cytokine, including B-cell activating factor (BAFF). This vaccine may enhance the local mucosal adaptive response, induce tissue-resident memory cells, and inhibit viral replication and clearance. However, further research is required to evaluate its safety and efficacy.