Incidence, risk factors, and clinical symptom profile of reinfection during Omicron-dominated COVID-19 outbreak in Hong Kong: A retrospective cohort study (preprint)

Background: Despite the declaration from World Health Organization of the end of the COVID-19 pandemic, reinfection persists and continues to strain the global healthcare system. With the emergence of the most recent variant of SARS-CoV-2 named JN.1, retrospective analysis of epidemiological characteristics of previous cases involving the Omicron variant is essential to provide references for preventing reinfection caused by the ongoing new SARS-Cov-2 variants. Methods: This retrospective cohort study included 6325 patients infected with SARS-CoV-2 during the Omicron-dominated outbreak (from December 2021 to May 2022) in Hong Kong. Statistical analysis was conducted to demonstrate the epidemiological characteristics and a logistic regression model was utilized to identify risk factors associated with reinfection. Results: The Omicron reinfection incidence was 5.18% (n = 353). No significant difference was observed in receiving mRNA (BNT162b2) vaccine and inactivated (CoronaVac) vaccine between reinfection and non-reinfection groups (p>0.05). Risk factors were identified as female gender (p<0.001), longer infection duration (p<0.05), comorbidity of eyes, ear, nose, throat disease (p<0.01), and severe post-infection impact on daily life and work (p<0.05), while equal or larger than 70 years old (p<0.05) and vaccination after primary infection (p<0.01) were associated with a lower risk of reinfection. The prevalence of most symptoms after reinfection was lower than the first infection, except for fatigue. Conclusion: No significant difference in mRNA (BNT162b2) vaccine and inactivated (CoronaVac) vaccine against reinfection. Post-infection vaccination could lower the risk of reinfection, which potentially inform the development of preventive measures including vaccination policies against potential new SARS-Cov-2 variants.

Metformin mitigates insulin signaling variations induced by COVID-19 vaccine boosters in type 2 diabetes (preprint)

Diabetes is associated with an increased risk of Coronavirus disease 2019 (COVID-19) vulnerability and mortality. COVID-19 vaccines significantly reduce the risks of serious COVID-19 outcomes, but the impact of COVID-19 vaccines including their effectiveness and adverse effects in patients with diabetes are not well known yet. Here, we showed that 61.1% patients with type 2 diabetes, but not healthy controls, exhibited aggravated insulin resistance towards the booster shots of the COVID-19 vaccine. Furthermore, we showed that COVID-19 vaccination once a week also impaired insulin sensitivity in healthy mice after four weeks. We further showed that metformin, a common anti-diabetic medication, improved the impaired insulin signaling induced by COVID-19 vaccination in mice. This study suggests clinical implications for the close monitoring of glycemic control in diabetic patients after receiving COVID-19 vaccines and indicates the beneficial action of metformin in counteracting insulin signaling variations induced by COVID-19 vaccination in diabetic patients.

Payments in the pandemic: orchestrating and imagining cross-boundary digital money infrastructures in China during COVID-19

Recent scholarship has sought to emphasise boundaries and borders as being complex social institutions that play a vital role in mediating national and global flows. This article examines transactions occurring along the boundary between Hong Kong and Mainland China, which experienced a sudden ?hardening? owing to travel restrictions imposed following the outbreak of COVID-19. When individuals found themselves unable to physically cross the boundary as per usual, they instead turned to mobile media to enact everyday transactions ? both financial and social ? between the two regions. Calling upon the notion of ?digital passages?, we argue that the appropriation of digital money infrastructures for managing such transactions should act as a reminder for scholars to productively engage with the various forms of boundaries and borders emerging within online spaces.