Ruth Drury

Abstract The immune mechanisms mediating COVID-19 vaccine attenuation of COVID-19 remain undescribed. We conducted comprehensive analyses detailing immune responses to SARS-CoV-2 virus in blood post-vaccination with ChAdOx1 nCoV-19 or a placebo. Samples from randomised placebo-controlled trials (NCT04324606 and NCT04400838) were taken at baseline, onset of COVID-19-like symptoms, and 7 days later, confirming COVID-19 using nucleic amplification test (NAAT test) via real-time PCR (RT-PCR).

Vaccines offer the best opportunity for bringing the COVID-19 pandemic under control. Several vaccines have now been authorised in multiple countries on the basis of demonstrated safety and efficacy in large-scale phase 3 trials., On Dec 8, 2020, the COVID-19 vaccine programme kicked off in the UK with the introduction of the Pfizer-BioNTech mRNA vaccine (BNT162b2). Within a month, the Oxford-AstraZeneca ChAdOx1 nCoV-19 (AZD1222) adenoviral vector vaccine had also been deployed.