COVID-19: UK experts make breakthrough advancement in search of vaccine
London: According to recent research published in the Lancet, a single dose of the vaccine called ChAdOx1 nCoV-19 elicits an increase in spike-specific antibodies and neutralising antibody after a booster dose. The study shows that the pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) might be curtailed by vaccination.
The study lead by Dr Pedro M Folegatti, assessed the safety, reactogenicity, and immunogenicity of a viral vectored coronavirus vaccine that expresses the spike protein of SARS-CoV-2. The researchers did a randomised controlled trial in five trial sites in the UK of a chimpanzee adenovirus-vectored vaccine (ChAdOx1 nCoV-19) expressing the SARS-CoV-2 spike protein compared with a meningococcal conjugate vaccine (MenACWY) as control.
1,077 healthy adults aged 18–55 years with no history of laboratory-confirmed SARS-CoV-2 infection or of COVID-19-like symptoms were randomly assigned (1:1) to receive ChAdOx1 nCoV-19 at a dose of 5 × 1010 viral particles or MenACWY as a single intramuscular injection. Ten participants assigned to a non-randomised, unblinded ChAdOx1 nCoV-19 prime-boost group received a two-dose schedule, with the booster vaccine administered 28 days after the first dose. Humoral responses at baseline and following vaccination were assessed using a standardised total IgG ELISA against trimeric SARS-CoV-2 spike protein. Cellular responses were assessed using an ex-vivo interferon-γ enzyme-linked immunospot assay. Analyses were done by group allocation in participants who received the vaccine. Safety was assessed over 28 days after vaccination.
The study titled ‘Safety and immunogenicity of the ChAdOx1 nCoV-19 vaccine against SARS-CoV-2: a preliminary report of a phase 1/2, single-blind, randomised controlled trial’ found that ChAdOx1 nCoV-19 showed an acceptable safety profile, and homologous boosting increased antibody response.
After the success of the initial phase of the experiment, the team of Dr Pedro are all set to take the study on a large-scale evaluation of vaccine to phase 3 programme.
The study is funded by UK Research and Innovation, Coalition for Epidemic Preparedness Innovations, National Institute for Health Research (NIHR), NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and the German Center for Infection Research (DZIF), Partner site Gießen-Marburg-Langen.