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Several teams have been publishing global estimates of excess deaths during the COVID-19 pandemic. Here, we examine potential flaws and underappreciated sources of uncertainty in global excess death calculations. Adjusting for changing population age structure is essential. Otherwise, excess deaths are markedly overestimated in countries with increasingly aging populations. Adjusting for changes in other high-risk indicators, such as residence in long-term facilities, may also make a difference. Death registration is highly incomplete in most countries; completeness corrections should allow for substantial uncertainty and consider that completeness may have changed during pandemic years. Excess death estimates have high sensitivity to modelling choice. Therefore different options should be considered and the full range of results should be shown for different choices of pre-pandemic reference periods and imposed models. Any post-modelling corrections in specific countries should be guided by pre-specified rules. Modelling of all-cause mortality (ACM) in countries that have ACM data and extrapolating these models to other countries is precarious; models may lack transportability. Existing global excess death estimates underestimate the overall uncertainty that is multiplicative across diverse sources of uncertainty. Informative excess death estimates require risk stratification, including age groups and ethnic/racial strata. Data to-date suggest a death deficit among children during the pandemic and marked socioeconomic differences in deaths, widening inequalities. Finally, causal explanations require great caution in disentangling SARS-CoV-2 deaths, indirect pandemic effects and effects from measures taken. We conclude that excess deaths have many uncertainties, but globally deaths from SARS-CoV-2 may be the minority of calculated excess deaths., (© 2023 The Authors. European Journal of Clinical Investigation published by John Wiley & Sons Ltd on behalf of Stichting European Society for Clinical Investigation Journal Foundation.)

Background: China witnessed a surge of Omicron infections after abandoning 'zero COVID' strategies on 7 December 2022. The authorities report very sparse deaths based on very restricted criteria, but massive deaths are speculated., Methods: We aimed to estimate the COVID-19 fatalities in Mainland China until summer 2023 using the experiences of Hong Kong and of South Korea in 2022 as prototypes. Both these locations experienced massive Omicron waves after having had very few SARS-CoV-2 infections during 2020-2021. We estimated age-stratified infection fatality rates (IFRs) in Hong Kong and South Korea during 2022 and extrapolated to the population age structure of Mainland China. We also accounted separately for deaths of residents in long-term care facilities in both Hong Kong and South Korea., Results: Infection fatality rate estimates in non-elderly strata were modestly higher in Hong Kong than South Korea and projected 987,455 and 619,549 maximal COVID-19 deaths respectively, if the entire China population were infected. Expected COVID-19 deaths in Mainland China until summer 2023 ranged from 49,962 to 691,219 assuming 25-70% of the non-elderly population being infected and variable protection of elderly (from none to three-quarter reduction in fatalities). The main analysis (45% of non-elderly population infected and fatality impact among elderly reduced by half) estimated 152,886-249,094 COVID-19 deaths until summer 2023. Large uncertainties exist regarding potential changes in dominant variant, health system strain and impact on non-COVID-19 deaths., Conclusions: The most critical factor that can affect total COVID-19 fatalities in China is the extent to which the elderly can be protected., (© 2023 The Authors. European Journal of Clinical Investigation published by John Wiley & Sons Ltd on behalf of Stichting European Society for Clinical Investigation Journal Foundation.)

The synthesis of the eight stereoisomers of muscarine has been efficiently accomplished by utilizing the two enantiomers of lactic esters as starting material. The synthetic strategy is based on a SnCl4-catalyzed addition of allyltrimethylsilane to O-protected lactic aldehydes followed by an iodocyclization process. All the final derivatives possess an enantiomeric excess higher than 98%. The four pairs of enantiomers bound to M1, M2, and M3 muscarinic receptor subtypes in membranes from cerebral cortex, heart, and salivary glands, respectively, and recognized heterogeneous states of the receptors. Of the eight isomers, only natural muscarine (+)-1 recognized three affinity states of the M2 receptor. The compound was also the only one to show selectivity in the binding study, demonstrating 37- to 44-fold higher affinity for the M2 than for the M1 or M3 receptors. In addition, the compounds were tested in functional assays on isolated guinea pig atria (M2 receptors) and ileum (mixed population of M2 and M3 receptors) and their muscarinic potencies were determined. Among the eight isomers, again only (+)-1 enantiomer was found to be very active on both tissues. Its potency was more than two orders of magnitude higher than that of its enantiomer (-)-1 as well as the other six isomers. The eudismic ratios (E.R.) deduced from the two functional tests were 324 and 331.