By: The Negros Times
Neutralising antibody levels against Omicron following a third dose boost of AstraZeneca’s COVID-19 Vaccine were broadly similar to levels achieved after two doses against the Delta variant.
University of Oxford study supports use of AstraZeneca’s COVID-19 vaccine as third dose booster against Omicron
AstraZeneca’s COVID-19 vaccine significantly boosted levels of antibodies against the Omicron SARS-CoV-2 variant following a third dose booster, according to data from a new laboratory study. Neutralization titres for Omicron were boosted following a third dose with AstraZeneca’s COVID-19 vaccine compared to titres after a second dose.
The levels seen after the third dose booster were higher than the neutralizing antibodies found in individuals who had been previously infected with and recovered naturally from COVID-19 (Alpha, Beta, Delta variants and original strain). Sera obtained from individuals one month after receiving the third dose booster vaccination neutralized the Omicron variant to levels that were broadly similar to those observed one month after the second dose against the Delta variant. Two doses of AstraZeneca’s COVID-19 vaccine have been associated with protection against the Delta variant in real-world studies.
The study analysed blood samples taken from individuals infected with COVID-19; those who had been vaccinated with a two-dose schedule and a third dose booster; and those who had reported previous infection from other COVID-19 variants of concern. The study included samples from 41 individuals who had received three doses of AstraZeneca’s COVID-19 vaccine.
The study was performed independently by investigators at the University of Oxford and the
findings were posted online on the bioRxiv pre print server.
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 programmes 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.”
Data from another laboratory study support AstraZeneca’s COVID-19 vaccine effect against Omicron, with individuals vaccinated with two doses of AstraZeneca’s COVID-19 vaccine retaining neutralizing activity against Omicron, although a decrease was seen compared to the original strain. 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.
AstraZeneca is collecting real-world evidence evaluating the effectiveness against the Omicron variant with academic groups in the southern African region. AstraZeneca is also analysing blood samples from participants in the Company’s Phase II/III trial to evaluate neutralising 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.
Currently available data against variants of concern, excluding Omicron, support the use of a
third booster with AstraZeneca’s COVID-19 vaccine as part of a homologous or heterologous
A subanalysis from the COV001 and COV002 trials 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 the trial, the third dose of AstraZeneca’s COVID-19 vaccine was less reactogenic than the first dose.
In addition, 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 (BNT162b2).
The University of Oxford Study:
The University of Oxford laboratory study assessed the neutralization of Omicron by a large panel of sera collected from convalescent early pandemic, Alpha, Beta, Gamma and Delta infected individuals, as well as from individuals that had received three doses of AstraZeneca’s COVID-19 vaccine or the Pfizer BioNTech (BNT162b2) vaccines. In total, samples were analysed from 41 individuals that had received three doses of AstraZeneca’s COVID-19 vaccine, and 20 individuals that had received three doses of Pfizer BioNTech (BNT162b2) vaccine.
AstraZeneca’s COVID-19 Vaccine:
AstraZeneca’s COVID-19 vaccine (ChAdOx1-S [Recombinant], formerly AZD1222) was co-invented by the University of Oxford and its spin-out company, Vaccitech. It uses a replication-deficient chimpanzee viral vector based on a weakened version of a common cold virus (adenovirus) that causes infections in chimpanzees and contains the genetic material of the SARS-CoV-2 virus spike protein. After vaccination, the surface spike protein is produced, priming the immune system to attack the SARS-CoV-2 virus if it later infects the body.
The vaccine has been granted a conditional marketing authorisation or emergency use in more than 90 countries. It also has Emergency Use Listing from the World Health Organization, which accelerates the pathway to access in up to 142 countries through the COVAX Facility.
Under a sub-license agreement with AstraZeneca, the vaccine is manufactured and supplied
by the Serum Institute of India under the name COVISHIELD.
In the Philippines, the COVID-19 Vaccine (ChAdOx1-S [recombinant]) COVAX Supply has
been given ‘emergency use listing’ by the World Health Organization. Similarly, the direct supply has been granted Emergency Use Authorization (EUA) by the Philippine Food and Drug Administration (FDA). This means that there is more evidence to come about this medicine. The World Health Organization and the Philippine FDA will review new information on this medicine as it becomes available and the leaflet will be updated as necessary. Please also note that the vaccine cannot be marketed or sold, advertised, or promoted.
AstraZeneca (LSE/STO/Nasdaq: AZN) is a global, science-led biopharmaceutical company that focuses on the discovery, development, and commercialisation of prescription medicines in Oncology, Rare Diseases, and BioPharmaceuticals, including Cardiovascular, Renal & Metabolism, and Respiratory & Immunology. Based in Cambridge, UK, AstraZeneca operates in over 100 countries and its innovative medicines are used by millions of patients worldwide.