Omicron: Two doses of AstraZeneca or Pfizer offer little protection against getting infected, new study confirms

Ross Lydall @RossLydall13 December 2021

A second study confirmed on Monday that two doses of AstraZeneca or Pfizer offers little protection against getting infected with Omicron – and in some cases none at all.

The draft research from Oxford university supports the findings from the UK Health Security Agency last Friday that two doses of the two most common vaccines used in the UK are less effective against symptomatic disease than they are against Delta.

However, Monday’s findings found no current evidence of an increased threat from Omicron to cause severe disease, hospitalisations or deaths in vaccinated populations.

The researchers also suggested that adapting vaccines to target Omicron could prevent them working against Delta – meaning future vaccines will have to be multi-strain effective, like the flu jab.

They said that an increase in infections, including in people who previously had Covid or had been double jabbed, was likely. As a result, getting the unvaccinated jabbed and encouraging boosters was the priority.

The study used blood samples from people who had had two jabs and tested the vaccine’s ability to neutralise Omicron.

Professor Gavin Screaton, lead author, said the research pressed home the message that those who are offered booster vaccination should take it.

“Whilst there is no evidence for increased risk of severe disease, or death, from the virus amongst vaccinated populations, we must remain cautious, as greater case numbers will still place a considerable burden on healthcare systems,” he said.

Professor Matthew Snape, the co-author, said: “These data are important but are only one part of the picture. They only look at neutralising antibodies after the second dose, but do not tell us about cellular immunity, and this will also be tested using stored samples once the assays are available.

“Importantly, we have not yet assessed the impact of a ‘third dose’ booster, which we know significantly increases antibody concentrations, and it is likely that this will lead to improved potency against the Omicron variant.”

Create a FREE account to continue reading

eros

Registration is a free and easy way to support our journalism.

Join our community where you can: comment on stories; sign up to newsletters; enter competitions and access content on our app.

Your email address

Must be at least 6 characters, include an upper and lower case character and a number

You must be at least 18 years old to create an account

* Required fields

Already have an account? SIGN IN

By clicking Create Account you confirm that your data has been entered correctly and you have read and agree to our Terms of use , Cookie policy and Privacy policy .

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Thank you for registering

Please refresh the page or navigate to another page on the site to be automatically logged in