Influenza and COVID-19 co-infection and vaccine effectiveness against severe cases: a mathematical modeling study.

Background: Influenza A virus have a distinctive ability to exacerbate SARS-CoV-2 infection proven by in vitro studies. Furthermore, clinical evidence suggests that co-infection with COVID-19 and influenza not only increases mortality but also prolongs the hospitalization of patients. COVID-19 is in a small-scale recurrent epidemic, increasing the likelihood of co-epidemic with seasonal influenza. The impact of co-infection with influenza virus and SARS-CoV-2 on the population remains unstudied. Method: Here, we developed an age-specific compartmental model to simulate the co-circulation of COVID-19 and influenza and estimate the number of co-infected patients under different scenarios of prevalent virus type and vaccine coverage. To decrease the risk of the population developing severity, we investigated the minimum coverage required for the COVID-19 vaccine in conjunction with the influenza vaccine, particularly during co-epidemic seasons. Result: Compared to the single epidemic, the transmission of the SARS-CoV-2 exhibits a lower trend and a delayed peak when co-epidemic with influenza. Number of co-infection cases is higher when SARS-CoV-2 co-epidemic with Influenza A virus than that with Influenza B virus. The number of co-infected cases increases as SARS-CoV-2 becomes more transmissible. As the proportion of individuals vaccinated with the COVID-19 vaccine and influenza vaccines increases, the peak number of co-infected severe illnesses and the number of severe illness cases decreases and the peak time is delayed, especially for those >60 years old. Conclusion: To minimize the number of severe illnesses arising from co-infection of influenza and COVID-19, in conjunction vaccinations in the population are important, especially priority for the elderly.

Text analysis of Macao's COVID-19 prevention and control policies: discussion on strategy evolution and public health capabilities.

Background: The global impact of the coronavirus disease 2019 (COVID-19) pandemic has been profound. Macao Special Administrative Region (SAR), renowned as an international hub for tourism and entertainment, has actively responded to the crisis. However, a comprehensive analysis detailing the evolution of Macao SAR's policies throughout this period is currently lacking. Methods: This study aims to comprehensively understand the decision-making processes, policy formulation, and implementation strategies of the Macao SAR government amidst the pandemic through the analysis of speeches and inquiries made by legislative council members and other relevant documents. Employing both quantitative and qualitative analytical methods, including word frequency analysis and word vector models, we identify key themes and patterns. Additionally, we conducted a comparative analysis of keyword frequencies during the two waves of the pandemic using radar charts. Results: The results indicate a heightened focus by the Macao SAR government on pandemic control measures and economic impacts. In response, the government formulated and implemented policies, provided support initiatives, and managed port clearance, all while focusing on enhancing healthcare infrastructure and community services. Conclusions: The government persistently amends its policies in response to the evolving challenges posed by the pandemic. The evolution of the dynamic Zero-COVID strategy highlights the government's adaptability and comprehensive consideration, ensuring public health and societal stability.

Temporary impact on medical system and effectiveness of mitigation strategies after COVID-19 policy adjustment in China: a modeling study.

Background: As China amends its "zero COVID" strategy, a sudden increase in the number of infections may overwhelm medical resources and its impact has not been quantified. Specific mitigation strategies are needed to minimize disruption to the healthcare system and to prepare for the next possible epidemic in advance. Method: We develop a stochastic compartmental model to project the burden on the medical system (that is, the number of fever clinic visits and admission beds) of China after adjustment to COVID-19 policy, which considers the epidemiological characteristics of the Omicron variant, age composition of the population, and vaccine effectiveness against infection and severe COVD-19. We also estimate the effect of four-dose vaccinations (heterologous and homologous), antipyretic drug supply, non-pharmacological interventions (NPIs), and triage treatment on mitigating the domestic infection peak. Result: As to the impact on the medical system, this epidemic is projected to result in 398.02 million fever clinic visits and 16.58 million hospitalizations, and the disruption period on the healthcare system is 18 and 30 days, respectively. Antipyretic drug supply and booster vaccination could reduce the burden on emergency visits and hospitalization, respectively, while neither of them could not reduce to the current capacity. The synergy of several different strategies suggests that increasing the heterologous booster vaccination rate for older adult to over 90% is a key measure to alleviate the bed burden for respiratory diseases on the basis of expanded healthcare resource allocation. Conclusion: The Omicron epidemic followed the adjustment to COVID-19 policy overloading many local health systems across the country at the end of 2022. The combined effect of vaccination, antipyretic drug supply, triage treatment, and PHSMs could prevent overwhelming medical resources.