期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2022
卷号：119
期号：33
DOI：10.1073/pnas.2201616119
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Significance
An efficacious pediatric SARS-CoV-2 vaccine is needed to halt the current pandemic. Mumps virus (MuV) vaccine is one of the safest and most efficient vaccines with a track record in children. Here, we developed recombinant MuV (rMuV)–based SARS-CoV-2 vaccine candidates expressing a stabilized prefusion spike with two prolines (preS-2P) or six prolines (preS-6P) at different gene junctions in the MuV genome. Among them, rMuV-based preS-6P vaccine candidates induce robust neutralizing antibodies, mucosal immunoglobulin A antibodies, and T cell immune responses, and provides complete protection against challenge with SARS-CoV-2 WA1 and Delta variants. The preexisting MuV immunity has a minimal impact on generating SARS-CoV-2–specific immune responses. Thus, rMuV-preS-6P is a highly efficacious SARS-CoV-2 vaccine candidate in current small-animal models.
With the rapid increase in SARS-CoV-2 cases in children, a safe and effective vaccine for this population is urgently needed. The MMR (measles/mumps/rubella) vaccine has been one of the safest and most effective human vaccines used in infants and children since the 1960s. Here, we developed live attenuated recombinant mumps virus (rMuV)–based SARS-CoV-2 vaccine candidates using the MuV Jeryl Lynn (JL2) vaccine strain backbone. The soluble prefusion SARS-CoV-2 spike protein (preS) gene, stablized by two prolines (preS-2P) or six prolines (preS-6P), was inserted into the MuV genome at the P–M or F–SH gene junctions in the MuV genome. preS-6P was more efficiently expressed than preS-2P, and preS-6P expression from the P–M gene junction was more efficient than from the F–SH gene junction. In mice, the rMuV-preS-6P vaccine was more immunogenic than the rMuV-preS-2P vaccine, eliciting stronger neutralizing antibodies and mucosal immunity. Sera raised in response to the rMuV-preS-6P vaccine neutralized SARS-CoV-2 variants of concern, including the Delta variant equivalently. Intranasal and/or subcutaneous immunization of IFNAR1
−/− mice and golden Syrian hamsters with the rMuV-preS-6P vaccine induced high levels of neutralizing antibodies, mucosal immunoglobulin A antibody, and T cell immune responses, and were completely protected from challenge by both SARS-CoV-2 USA-WA1/2020 and Delta variants. Therefore, rMuV-preS-6P is a highly promising COVID-19 vaccine candidate, warranting further development as a tetravalent MMR vaccine, which may include protection against SARS-CoV-2.
