ABSTRACT
Current COVID-19 vaccines have been associated with a decline in infection rates, prevention of severe disease and a decrease in mortality rates. However, SARS-CoV-2 variants are continuously evolving, and development of new accessible COVID-19 vaccines is essential to mitigate the pandemic. Here, we present data on preclinical studies in mice of a receptor-binding domain (RBD)-based recombinant protein vaccine (PHH-1V) consisting of an RBD fusion heterodimer comprising the B.1.351 and B.1.1.7 SARS-CoV-2 variants formulated in SQBA adjuvant, an oil-in-water emulsion. A prime-boost immunisation with PHH-1V in BALB/c and K18-hACE2 mice induced a CD4+ and CD8+ T cell response and RBD-binding antibodies with neutralising activity against several variants, and also showed a good tolerability profile. Significantly, RBD fusion heterodimer vaccination conferred 100% efficacy, preventing mortality in SARS-CoV-2 infected K18-hACE2 mice, but also reducing Beta, Delta and Omicron infection in lower respiratory airways. These findings demonstrate the feasibility of this recombinant vaccine strategy. Graphical
ABSTRACT
Current COVID-19 vaccines have been associated with a decline in infection rates, prevention of severe disease, and a decrease in mortality rates. However, SARS-CoV-2 variants are continuously evolving, and development of new accessible COVID-19 vaccines is essential to mitigate the pandemic. Here, we present data on preclinical studies in mice of a receptor-binding domain (RBD)-based recombinant protein vaccine (PHH-1V) consisting of an RBD fusion heterodimer comprising the B.1.351 and B.1.1.7 SARS-CoV-2 variants formulated in SQBA adjuvant, an oil-in-water emulsion. A prime-boost immunisation with PHH-1V in BALB/c and K18-hACE2 mice induced a CD4+ and CD8+ T cell response and RBD-binding antibodies with neutralizing activity against several variants, and also showed a good tolerability profile. Significantly, RBD fusion heterodimer vaccination conferred 100% efficacy, preventing mortality in SARS-CoV-2 infected K18-hACE2 mice, but also reducing Beta, Delta and Omicron infection in lower respiratory airways. These findings demonstrate the feasibility of this recombinant vaccine strategy.
ABSTRACT
OBJECTIVE: During the SARS-CoV-2 state of alarm (SoA), a 30-70% reduction was observed in the number of visits to Pediatric Emergency Departments (ED), as well as frequent delay in diagnosis or difficulty accessing healthcare services. Here we evaluate modifications observed in pediatric healthcare activity during the SoA. STUDY DESIGN: Descriptive retrospective observational study of the hospital pediatric activity. METHOD: We compared the use of pediatric healthcare services during the SoA (March 11th - June 25th, 2020) versus the use during the equivalent periods of years 2018 and 2019, in the "Complejo Hospitalario Universitario Insular Materno Infantil de Canarias" (Mother and Child University Hospital of the Canary Islands). RESULTS: The number of patients visiting the pediatric ED decreased by 66.75% on average (95%CI: -65.6; - 67.7; p < 0.001), with a peak reduction (70.4%; 95%CI: -69.0; -71.7; p < 0.001) during the lockdown. We observed an increase in the number of cases of psychiatric disorders, foreign body ingestions and intoxications, as well as a decrease in respiratory conditions. Hospital admissions decreased by 45.5% (95%CI: - 38.9; -51.3; p < 0.001), while the ratio and duration of hospital stay increased. A proportion of 3.95% of admitted patients experienced complications caused by delayed visit to the ED. CONCLUSIONS: The study shows that more patient education campaigns are needed to improve the efficiency of emergency services. It is important to reinforce the message that adequate healthcare service management is necessary.