A study done by investigators at the University of Oxford reported that for people who have received a booster of AstraZeneca’s COVID-19 vaccine had neutralization titres for Omicron that were higher compared to both samples from people having only 2 doses and those who were previously infected with and recovered from earlier COVID-19 variants.
Professor Sir John Bell, Regius Professor of Medicine, University of Oxford, UK and one of the study investigators, said: “It is very encouraging to see that current vaccines have the potential to protect against Omicron following a third dose booster. These results support the use of third dose boosters as part of national vaccine strategies, especially to limit the spread of variants of concern, including Omicron.”
Sir Mene Pangalos, Executive Vice President, BioPharmaceuticals R&D, AstraZeneca said: “AstraZeneca’s COVID-19 vaccine plays an important role in vaccination program around the world and these data give us confidence that the vaccine should be given as a third dose booster. It is also important to look beyond antibodies to better understand how vaccines offer protection against Omicron. As we better understand Omicron, we believe we will find that T-cell response provides durable protection against severe disease and hospitalizations.”
A sub analysis from the University of Oxford’s COV001 and COV002 AstraZeneca vaccine trials in the United States demonstrated that a third dose of AstraZeneca’s COVID-19 vaccine given at least six months after a second dose boosted antibody levels six-fold and maintained T cell response. A third dose also resulted in higher neutralizing activity against the Alpha, Beta, and Delta variants, compared with a two-dose regimen.
In other studies, AstraZeneca’s COVID-19 vaccine has been shown to generate a diverse and durable T-cell response to multiple variants resulting in a broader response than antibodies alone, which could contribute to protection against COVID-19. The COV-BOOST trial showed that a third dose booster of AstraZeneca’s COVID-19 vaccine induced significantly higher immune responses compared with controls against the Delta variant and original strain following a primary vaccine series of AstraZeneca’s COVID-19 vaccine or Pfizer BioNtech.
AstraZeneca is also analyzing blood samples from participants in the Company’s Phase II/III trial to evaluate neutralizing activity when given as a third dose booster against Omicron for both AstraZeneca’s COVID-19 vaccine and its investigational next generation COVID-19 vaccine, AZD2816. Data from these studies are expected soon.
