[Analysis of RNA virus pathogenicity and development of novel prevention methods.]

In the first quarter of the 21st century, infectious diseases caused by RNA viruses such as SARS, pandemic influenza viruses, MERS, Zika virus, and SARS-CoV-2 have spread. When such emerging and re-emerging viruses occur and spread, it is important for public health to quickly analyze the characteristics of these viruses and develop preventive measures. We found that the Zika virus causes damage to the testes, leading to testicular atrophy; that a vaccine based on mosquito salivary gland proteins suppresses mosquito-borne Zika virus transmission/infection; that the pathogenicity of SARS-CoV-2 Omicron variants BA.2, BA.4, and BA.5 isolated from patients is comparable to that of Omicron BA.1; and that a strategy targeting regulatory T cells to enhance vaccine efficacy is effective. Here, I would like to briefly discuss these findings.