Last checked at 
* Antibody levels with booster similar to two doses against
Delta
* Protection also higher than those previously infected
* Oxford researchers independent from vaccine partners
(Adds more details on study, executive comment, background)
By Pushkala Aripaka
Dec 23 (Reuters) - A three-dose course of AstraZeneca's
COVID-19 vaccine is effective against the
rapidly-spreading Omicron coronavirus variant, the
pharmaceutical company said on Thursday, citing data from an
Oxford University lab study https://www.astrazeneca.com/content/astraz/media-centre/press-releases/2021/vaxzevria-significantly-boosted-antibody-levels-against-omicron.html.
Findings from the study, yet to be published in a
peer-reviewed medical journal, match those from rivals
Pfizer-BioNTech https://www.reuters.com/business/healthcare-pharmaceuticals/biontech-pfizer-say-test-shows-3-doses-vaccine-neutralise-omicron-2021-12-08
and Moderna https://www.reuters.com/business/healthcare-pharmaceuticals/moderna-says-booster-dose-its-covid-19-vaccine-appears-protective-vs-omicron-2021-12-20
which have also found a third dose of their shots
works against Omicron.
The study on AstraZeneca's vaccine, Vaxzevria, showed that
after a three-dose course of the vaccine, neutralising levels
against Omicron were broadly similar to those against the
virus's Delta variant after two doses.
The London-listed company said researchers at Oxford
University who carried out the study were independent from those
who worked on the vaccine with AstraZeneca.
"As we better understand Omicron, we believe we will find
that T-cell response provides durable protection against severe
disease and hospitalisations," Mene Pangalos, the head of
AstraZeneca's biopharmaceuticals R&D said, referring to a
critical component of the immune system that respond to fight
infection.
Antibody levels against Omicron after the booster shot were
higher than antibodies in people who had been infected with and
recovered naturally from COVID-19, the Anglo-Swedish drugmaker
added.
Although the early data is positive for the company,
AstraZeneca said https://www.reuters.com/business/healthcare-pharmaceuticals/oxford-astrazeneca-launch-work-omicron-targeted-vaccine-ft-2021-12-21
on Tuesday it was working with its partner Oxford University to
produce a vaccine tailored for Omicron, joining similar efforts
from other vaccine-makers.
The Oxford study analysed blood samples from those infected
with COVID-19, those vaccinated with two doses and a booster,
and those previously infected with other variants of concern. It
included samples from 41 people given three doses of Vaxzevria.
Scientists and governments are scrambling to bolster
defences against Omicron with shots and therapies, as the
variant threatens to become dominant globally and has prompted
renewed curbs ahead of the holidays to contain infections.
Britain earlier this month backed https://www.reuters.com/world/uk/boosters-give-70-75-protection-against-mild-disease-omicron-uk-health-security-2021-12-10
the use of boosters after it found that a third dose
significantly restored protection against mild disease caused by
Omicron, in part reversing an otherwise steep drop in vaccine
effectiveness.
(Reporting by Pushkala Aripaka in Bengaluru; Editing by Shounak
Dasgupta, John Stonestreet and Elaine Hardcastle)
