Addressing Unmet Needs in Vaccination for Older Adults in the Asia Pacific: Insights from the COVID-19 Pandemic.

The impact of vaccinating the older population against vaccine-preventable diseases in terms of health, social and economic benefits has been increasingly recognised. However, there is a gap in the utilisation of vaccines worldwide. The population is ageing at an unprecedented pace in the Asia-Pacific (APAC) region, with the number of persons older than 65 years set to double by 2050 to around 1.3 billion. More than 18% of the population in Japan, Hong Kong, and China is over the age of 65 years. This highlights the importance of prioritising resources to address societal obligations toward the needs of the ageing generation. This review provides an overview of the challenges to adult vaccination in APAC, drivers to increase vaccination coverage, vaccination insights gained through the COVID-19 pandemic, and potential measures to increase the uptake of adult vaccines in the region.

Efficacy of the combination of monoclonal antibodies against the SARS-CoV-2 Beta and Delta variants.

The pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently the biggest healthcare issue worldwide. This study aimed to develop a monoclonal antibody against SARS-CoV-2 from B cells of recovered COVID-19 patients, which might have beneficial therapeutic purposes for COVID-19 patients. We successfully generated human monoclonal antibodies (hmAbs) against the receptor binding domain (RBD) protein of SARS-CoV-2 using developed hybridoma technology. The isolated hmAbs against the RBD protein (wild-type) showed high binding activity and neutralized the interaction between the RBD and the cellular receptor angiotensin-converting enzyme 2 (ACE2) protein. Epitope binning and crystallography results displayed target epitopes of these antibodies in distinct regions beneficial in the mix as a cocktail. The 3D2 binds to conserved epitopes among multi-variants. Pseudovirion-based neutralization results revealed that the antibody cocktail, 1D1 and 3D2, showed high potency in multiple variants of SARS-CoV-2 infection. In vivo studies showed the ability of the antibody cocktail treatment (intraperitoneal (i.p.) administration) to reduce viral load (Beta variant) in blood and various tissues. While the antibody cocktail treatment (intranasal (i.n.) administration) could not significantly reduce the viral load in nasal turbinate and lung tissue, it could reduce the viral load in blood, kidney, and brain tissue. These findings revealed that the efficacy of the antibody cocktail, 1D1 and 3D2, should be further studied in animal models in terms of timing of administration, optimal dose, and efficacy to mitigate inflammation in targeted tissue such as nasal turbinate and lung.

Endotoxemia and circulating bacteriome in severe COVID-19 patients.

BACKGROUND: When severe, COVID-19 shares many clinical features with bacterial sepsis. Yet, secondary bacterial infection is uncommon. However, as epithelium is injured and barrier function is lost, bacterial products entering the circulation might contribute to the pathophysiology of COVID-19. METHODS: We studied 19 adults, severely ill patients with COVID-19 infection, who were admitted to King Chulalongkorn Memorial Hospital, Bangkok, Thailand, between 13th March and 17th April 2020. Blood samples on days 1, 3, and 7 of enrollment were analyzed for endotoxin activity assay (EAA), (1 → 3)-ß-D-glucan (BG), and 16S rRNA gene sequencing to determine the circulating bacteriome. RESULTS: Of the 19 patients, 13 were in intensive care and 10 patients received mechanical ventilation. We found 8 patients with high EAA (≥ 0.6) and about half of the patients had high serum BG levels which tended to be higher in later in the illness. Although only 1 patient had a positive blood culture, 18 of 19 patients were positive for 16S rRNA gene amplification. Proteobacteria was the most abundant phylum. The diversity of bacterial genera was decreased overtime. CONCLUSIONS: Bacterial DNA and toxins were discovered in virtually all severely ill COVID-19 pneumonia patients. This raises a previously unrecognized concern for significant contribution of bacterial products in the pathogenesis of this disease.