expert reaction to preprint from Oxford looking at efficacy of the Oxford AstraZeneca vaccine against the B.1.1.7 ‘Kent’ UK variant of SARS-CoV-2


A preprint, an unpublished non-peer reviewed study, looks at efficacy of the Oxford/AstraZeneca vaccine against the ‘Kent’ variant of SARS-CoV-2, B.1.1.7.


Dr Peter English, Consultant in Communicable Disease Control, Former Editor of Vaccines in Practice Magazine, Immediate past Chair of the BMA Public Health Medicine Committee, said:

“This is excellent news.  It reminds us that neutralising antibody titres are not all that matters.  Immunity to disease is what matters: antibody titres are part of this, but other factors including T-cell responses also matter.

“In this study, participants were routinely swabbed to see if they had become infected.  They also provided information on any symptoms or illness they experienced.

“Swabs from 256 participants were successfully sequenced – which means that the investigators knew exactly which viral variant they had been infected with.

“Participants who had been infected with the virus’ B.1.1.7 variant were no more likely to become ill than participants who had the previous variants, against which the vaccine could be expected to work.  This is excellent news, as it indicates that the vaccine works effectively at preventing illness, even with the variant virus.

“The study also found that the amount of virus found on swabs of vaccinated people was lower than you would have expected in non-vaccinated individuals, and the virus was present for less time – suggesting that the vaccine not only protects recipients against infection, but it also means they are less likely to become infected; and if they do have asymptomatic infection, they are less likely to transmit it to other people.  This is very important.  There are two things we need from vaccines: that they reduce the burden of disease and the pressure on health services by preventing serious illness – death, ICU admissions, and hospital admissions – and that they reduce transmission, so that we can get the effective R number below one, so the disease will die out, and so that there is less viral replication and thus less likelihood of variants of concern arising.”


Dr June Raine, MHRA Chief Executive, said:

“The findings of this study are very reassuring.  The pre-print contains the first published clinical data showing that COVID-19 Vaccine AstraZeneca is effective at protecting against the B.1.1.7 variant, also known as the ‘Kent variant’.

“It also provides data suggesting that this vaccine may reduce transmission of the disease.”



Preprint (not a paper): ‘Efficacy of ChAdOx1 nCoV-19 (AZD1222) Vaccine Against SARS-CoV-2 VOC 202012/01 (B.1.1.7)’ by Katherine R. W. Emary et al. was posted on the ‘Preprints with the Lancet’ preprint server on Friday 5 February 2021.  This work is not peer-reviewed.



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Declared interests

Dr Peter English: “I have no interests to declare.”

None others received.