Safety and humoral immunogenicity of the ChAdOx1 nCoV-19 vaccine administered as a fourth dose booster following two doses of ChAdOx1 nCoV-19 and a third dose of BNT162b2 (COV009): A prospective cohort study.

Objectives: Evaluation of the safety and humoral immunogenicity of ChAdOx1 nCoV-19 as a fourth dose booster in individuals who have had two initial doses of the vaccine and a third dose of BNT162b2.

Methods: COV009 is a safety follow-up study of volunteers enroled in the pivotal pre-licensure ChAdOx1 nCoV-19. In this sub-study, 149 eligible participants were given a fourth dose of ChAdOx1 nCoV-19.

R21 in Matrix-M adjuvant in UK malaria-naive adult men and non-pregnant women aged 18-45 years: an open-label, partially blinded, phase 1-2a controlled human malaria infection study.

Background: R21 is a novel malaria vaccine, composed of a fusion protein of the malaria circumsporozoite protein and hepatitis B surface antigen. Following favourable safety and immunogenicity in a phase 1 study, we aimed to assess the efficacy of R21 administered with Matrix-M (R21/MM) against clinical malaria in adults from the UK who were malaria naive in a controlled human malaria infection study.

Methods: In this open-label, partially blinded, phase 1-2A controlled human malaria infection study undertaken in Oxford, Southampton, and London, UK, we tested five novel vaccination regimens of R21/MM.

Procalcitonin-guided duration of antibiotic treatment in children hospitalised with confirmed or suspected bacterial infection in the UK (BATCH): a pragmatic, multicentre, open-label, two-arm, individually randomised, controlled trial.

Background: Procalcitonin is a rapid response biomarker specific for bacterial infection, which is not routinely used in the UK National Health Service. We aimed to assess whether using a procalcitonin-guided algorithm would safely reduce the duration of antibiotic therapy compared with usual care, in which C-reactive protein is the commonly used biomarker.

Methods: The BATCH trial was a pragmatic, multicentre, open-label, parallel, two-arm, individually randomised, controlled trial conducted in 15 hospitals in England and Wales.

Local and systemic reactogenicity after mRNA and protein-based COVID-19 vaccines compared to meningococcal vaccine (MenACWY) in a UK blinded, randomized phase 2 trial (COV-BOOST).

Reactogenicity, the occurrence of vaccine side effects, can impact vaccine acceptance. There is limited data comparing the reactogenicity of COVID-19 vaccines to other routinely used vaccines, such as the meningococcal conjugate vaccine (MenACWY). In a trial of UK adults, participants received a third COVID-19 vaccine dose (NVX-CoV2373, BNT162b2, or mRNA1273) alongside MenACWY as an active control.

The Platform Trial In COVID-19 priming and BOOsting (PICOBOO): The immunogenicity, reactogenicity, and safety of licensed COVID-19 vaccinations administered as a second booster in BNT162b2 primed individuals aged 18-<50 and 50-<70 years old.

Objectives: PICOBOO is a randomised, adaptive trial evaluating the immunogenicity, reactogenicity, and safety of COVID-19 booster strategies. Here, we present data for second boosters among individuals aged 18-<50 and 50-<70 years old primed with BNT162b2 until Day (D) 84.

Methods: Immunocompetent adults who had received two doses of BNT162b2 and any licensed COVID-19 booster at least three months prior were eligible.