RESUMO
The coronavirus diseases 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections have threatened the world for more than 2 years. Multiple vaccine candidates have been developed and approved for emergency use by specific markets, but multiple doses are required to maintain the antibody level. Preliminary safety and immunogenicity data about an oral dose vaccine candidate using recombinant Bacillus subtilis in healthy adults were reported previously from an investigator-initiated trial in Hong Kong. Additional data are required in order to demonstrate the safety and efficacy of the candidate as a heterologous booster in vaccinated recipients. In an ongoing, placebo-controlled, observer-blinded, fixed dose, investigator-initiated trial conducted in the Macau, we randomly assigned healthy adults, 21 to 62 years of age to receive either placebo or a Bacillus subtilis oral dose vaccine candidate, which expressed the spike protein receptor binding domain of SARS-CoV-2 on the spore surface. The primary outcome was safety (e.g., local and systemic reactions and adverse events); immunogenicity was a secondary outcome. For both the active vaccine and placebo, participants received three courses in three consecutive days. A total of 16 participants underwent randomization: 9 participants received vaccine and 7 received placebo. No observable local or systemic side-effect was reported. In both younger and older adults receiving placebo, the neutralizing antibody levels were gradually declining, whereas the participants receiving the antibody booster showed an increase in neutralizing antibody level.
RESUMO
BACKGROUND: Pathogenic mutation in BRCA genes causes high cancer risk. Identifying the mutation carriers plays key roles in preventing BRCA mutation-related cancer. Population screening has demonstrated its power for comprehensive identification of the mutation carriers. However, it is only recommended for the Ashkenazi Jewish population with high prevalence of three founder mutations, but not for non-Ashkenazi Jewish populations as the cost-effectiveness could be too low due to their lower mutation prevalence and lack of founder mutation. Population screening would not benefit the majority of the human population for BRCA mutation-related cancer prevention. METHODS: We used population BRCA screening in 6000 residents, 1% of the Macau population, an ethnic Chinese population with unique genetic, linguistic and cultural features, and its BRCA mutation has not been analysed before. RESULTS: We called BRCA variants, identified 18 carriers with 14 pathogenic mutations and determined the prevalence of 0.29% in the population (95% CI 0.15% to 0.42%). We compared the testing cost between the Ashkenazi Jewish population, the Sephardi Jewish population and the Macau population, and observed only a few fold differences. CONCLUSION: Our study shows that testing cost is not the most important factor in considering population BRCA screening, at least for the populations in the developed countries/regions, regardless of the status of mutation prevalence and founder mutation.
