Polymerized Porin as a Novel Delivery Platform for Coronavirus Vaccine (preprint)

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), seriously threatens human life and health. The correct folding and polymerization of the receptor-binding domain (RBD) protein of coronavirus in Escherichia coli may reduce the cost of SARS-CoV-2 vaccines. Here, we designed this nanopore by using the principle of ClyA porin polymerization triggered by the cell membrane. We use surfactants to "pick" the ClyA-RBD nanopore from the bacterial outer membrane in this study. More importantly, the polymerized RBD displayed on ClyA-RBD polymerized porin (RBD-PP) already has some correct spatial structures of virus spikes. The nanostructures of RBD-PP can target lymph nodes and promote antigen uptake and processing by dendritic cells, thereby effectively eliciting the production of anti-SARS-CoV-2 neutralizing antibodies and systemic cellular immune responses and immune memory. We applied ofthis PP-based vaccine platform to make an RBD-based subunit vaccine against SARS-CoV-2, which will provide a foundation for the development of inexpensive coronavirus vaccines. The development of novel vaccine delivery system is an important part of innovative drug research. This novel PP-based vaccine platform is likely to be applied to more fields, including other viral vaccines, bacterial vaccines, tumor vaccines, drug delivery, and disease diagnosis.

Challenges in the Practice of Sexual Medicine in the Time of COVID-19 in China

BACKGROUND: In March 2020, the World Health Organization declared coronavirus disease 2019 (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a pandemic. Currently, data on changes in sexual behavior during the COVID-19 outbreak are limited. AIM: The present study aimed to obtain a preliminary understanding of the changes in people's sexual behavior, as a result of the pandemic, and explore the context in which they manifest. METHODS: A convenience sample of 270 men and 189 women who completed an online survey consisting of 12 items plus an additional question were included in the study. OUTCOMES: The study outcomes were obtained using a study-specific questionnaire to assess the changes in people's sexual behavior. RESULTS: While there was a wide range of individual responses, our results showed that 44% of participants reported a decrease in the number of sexual partners and about 37% of participants reported a decrease in sexual frequency. Multiple regression analysis showed that age, partner relationship, and sexual desire were closely related to sexual frequency. In addition, we found that most individuals with risky sexual experiences had a rapid reduction in risky sexual behavior. CLINICAL IMPLICATIONS: The current findings contribute to identifying another potential health implication associated with the COVID-19 pandemic and report preliminary evidence of the need to provide potential interventions for the population. STRENGTH & LIMITATIONS: This study is the first to perform a preliminary exploration of sexual behavior during the COVID-19 outbreak. The generalizability of the results is limited, given that only a small convenience sample was used. CONCLUSION: During the height of the COVID-19 outbreak, overall sexual activity, frequency, and risky behaviors declined significantly among young men and women in China. Li W, Li G, Xin C, et al. Challenges in the Practice of Sexual Medicine in the Time of COVID-19 in China. J Sex Med 2020;17:1225-1228.