Antigenic analysis of 10 strains of Coxsackievirus type A 24 (CA24) was carried out by monoclonal antibodies (McAbs) prepared with a China isolate of Coxsackievirus A 24 variant (CA24v).8 McAbs which were positive in indirect immunofluorescent test reacted to 9 CA 24 v detected. Of them, 4 McAbs could react to both CA 24v and CA 24 prototype (Joseph strain),and the others did not react to CA 24 prototype. 5 McAbs possessing virus-neutralizing activity did not neutralized CA 24 prototype (Joseph strain)and only one of them could neutralize EH 24/70 strain weakly, three of them neutralize 2 isolate from Japan in 1985-86 (J140/85 and J 60/86) and one isolate Fujian of China in 1986. However, all 5 McAbs above could neutralize isolate from Henan and Shanghai of China in 1986 as well as Beijing, Liaoning and Fujian of China in 1988.

The aim of this study was to prepare a self-assembled nanoparticle monkeypox vaccine candidate and study its immune response characteristics,so as to provide reference test data for its vaccine design.The antigen protein A29L-SpyTag and the backbone protein Mi3-SpyCatcher were expressed and purified by prokaryotic system,and nanoparticles A29L-Mi3 were prepared by chemical assembly,then the antibody titers were determined by ELISA,the antibody neutralization was determined by plaque test,and the cytokine secretion of lymphocytes was determined by flow cytometry to describe the immune response characteristics.Data showed that A29L-Mi3 nanoparticles were successfully prepared,and the particles were uniformly distributed in hollow cages,with an average particle size of(29±0.19)nm.After the A29L-Mi3 nanoparticle vaccine candidate was combined with SP01 adjuvant,the neutralizing antibody titer was stronger than that of the A29L protein candidate,and the A29L-Mi3 nanoparticle vaccine candidate could obtain neutralizing antibodies with similar titers after two immunizations.The level of mouse T lymphocyte immune response activated by the A29L-Mi3 nanoparticle vaccine candidate was higher than that of the A29L protein vaccine candidate.In conclusion,A29L-Mi3 protein nanoparticles with uniform structure have successfully assembled in vitro,which has strong immunogenicity and improved neutralization ability after combination with SP01 adjuvant,thus provided reference data for the optimization of immune programs.In addition,the level of cellular immune response is higher than that of A29L protein alone,which provides a reference for the design and development of monkeypox vaccine.