Pfizer and AstraZeneca’s COVID-19 vaccines are not as effective in fighting off the Omicron variant compared to other strains, according to a new study published by the University of Oxford Monday.
Researchers said in the pre-print paper they had discovered a “substantial fall” in neutralizing antibodies when the Omicron variant was introduced to blood samples 28 days after participants received their second dose of either Pfizer or AstraZeneca’s vaccine.
The study, which has yet to be peer-reviewed, discovered that some of the participants “failed to neutralize [the virus] at all.”
“This will likely lead to increased breakthrough infections in previously infected or double vaccinated individuals, which could drive a further wave of infection, although there is currently no evidence of increased potential to cause severe disease, hospitalization or death,” the study’s authors said.
But scientists said that more research is needed to determine whether the variant evades other types of immunity provided by the covid vaccines.
“These data are important but are only one part of the picture. They only look at neutralizing antibodies after the second dose, but do not tell us about cellular immunity, and this will also be tested,” said Matthew Snape, Oxford professor and co-author of the paper.
The researchers also added that the findings should “press 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,” said Gavin Screaton, head of the university’s medical sciences department and lead author of the paper.