Oxford-AstraZeneca vaccine against COVID-19 found to be effective up to 90% in Phase III trials


The interim trial data from its Phase III trials that show its candidate vaccine is effective at preventing COVID-19 (SARS-CoV-2) and offers a high level of protection

The University of Oxford, in collaboration with AstraZeneca plc, on Monday announced that its vaccine against COVID-19 has been found to be effective up to 90 during its Phase III trials.

The interim trial data from its Phase III trials that show its candidate vaccine, ChAdOx1 nCoV-2019, is effective at preventing COVID-19 (SARS-CoV-2) and offers a high level of protection, said University of Oxford in a statement.

Meanwhile, the Pune-based Serum Institute of India, the domestic partner of AstraZeneca, the Gates Foundation and the Gavi vaccine alliance to produce more than a billion doses of a COVID-19 vaccine for global supply, said that it would provide more details on the drug on Monday evening.

“I am delighted to hear that, Covishield, a low-cost, logistically manageable & soon to be widely available, #COVID19 vaccine, will offer protection up to 90% in one type of dosage regime and 62% in the other dosage regime. Further details on this, will be provided this evening,” said Adar Poonawalla, chief executive officer, Serum Institute of India.

Phase 3 interim analysis including 131 COVID-19 cases indicates that the vaccine is 70.4 percent effective when combining data from two dosing regimens. In the two different dose regimens vaccine efficacy was 90 percent in one and 62 percent in the other, said University of Oxford in the statement.

“Today marks an important milestone in the fight against #COVID19. Interim data show the #OxfordVaccine is 70.4% effective, & tests on two dose regimens show that it could be 90%, moving us one step closer to supplying it at low cost around the world,” said University of Oxford in a tweet.

Higher efficacy regimen used a halved first dose and standard second dose, it said.

Early indication that vaccine could reduce virus transmission from an observed reduction in asymptomatic infections and there were no hospitalised or severe cases in anyone who received the vaccine, said Oxford University.

“Large safety database from over 24,000 volunteers from clinical trials in the UK, Brazil and South Africa, with follow up since April,” said University of Oxford.

Crucially, vaccine can be easily administered in existing healthcare systems, stored at ‘fridge temperature’ (2-8 °C) and distributed using existing logistics, it said adding large scale manufacturing ongoing in over 10 countries to support equitable global access.

Professor Andrew Pollard, Director of the Oxford Vaccine Group and Chief Investigator of the Oxford Vaccine Trial, said, “These findings show that we have an effective vaccine that will save many lives. Excitingly, we’ve found that one of our dosing regimens may be around 90% effective and if this dosing regimen is used, more people could be vaccinated with planned vaccine supply. Today’s announcement is only possible thanks to the many volunteers in our trial, and the hard working and talented team of researchers based around the world.”

Meanwhile, AstraZeneca said that positive high-level results from an interim analysis of clinical trials of AZD1222 in the UK and Brazil showed the vaccine was highly effective in preventing COVID-19, the primary endpoint, and no hospitalisations or severe cases of the disease were reported in participants receiving the vaccine. There were a total of 131 COVID-19 cases in the interim analysis.

“One dosing regimen showed vaccine efficacy of 90 percent when AZD1222 was given as a half dose, followed by a full dose at least one month apart, and another dosing regimen showed 62 percent efficacy when given as two full doses at least one month apart. The combined analysis from both dosing regimens resulted in an average efficacy of 70 percent. All results were statistically significant,” said the UK-based pharma company.

It said that more data will continue to accumulate and additional analysis will be conducted, refining the efficacy reading and establishing the duration of protection.

Image credit: University of Oxford

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