AstraZeneca-Oxford COVID-19 Vaccine Achieves Average 70% Efficacy Without Any Side Effects in Clinical Trials

AstraZeneca Plc (Cambridgeshire, England) has reported positive high-level results from an interim analysis of clinical trials of its COVID-19 vaccine candidate developed by the University of Oxford (Oxford, UK).

The clinical trials of the coronavirus vaccine AZD1222 in the UK and Brazil showed that it was highly effective in preventing COVID-19 and met the primary endpoint without any hospitalizations or severe cases of the disease being reported in participants receiving the vaccine. There were a total of 131 COVID-19 cases in the interim analysis. The pooled analysis included data from the COV002 Phase II/III trial in the UK and COV003 Phase III trial in Brazil. Over 23,000 participants are being assessed following two doses of either a half-dose/full-dose regimen or a regimen of two full doses of AZD1222 or a comparator, meningococcal conjugate vaccine called MenACWY or saline.

One dosing regimen showed vaccine efficacy of 90% when AZD1222 was given as a half dose, followed by a full dose at least one month apart, and another dosing regimen showed 62% 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%. An independent Data Safety Monitoring Board has determined that the analysis met its primary endpoint showing protection from COVID-19 occurring 14 days or more after receiving two doses of the vaccine. No serious safety events related to the vaccine have been confirmed and AZD1222 was well tolerated across both dosing regimens.

AstraZeneca will now immediately prepare regulatory submission of the data to authorities around the world that have a framework in place for conditional or early approval. The company will seek an Emergency Use Listing from the World Health Organization for an accelerated pathway to vaccine availability in low-income countries. AstraZeneca is making rapid progress in manufacturing with a capacity of up to three billion doses of the vaccine in 2021 on a rolling basis, pending regulatory approval. The vaccine can be stored, transported and handled at normal refrigerated conditions (2-8 degrees Celsius/ 36-46 degrees Fahrenheit) for at least six months and administered within existing healthcare settings.

“These findings show that we have an effective vaccine that will save many lives,” said Professor Andrew Pollard, Chief Investigator of the Oxford Vaccine Trial at Oxford. “Excitingly, we’ve found that one of our dosing regimens may be around 90% effective and if this dosing regime 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.”

“Today marks an important milestone in our fight against the pandemic,” said Pascal Soriot, Chief Executive Officer. “This vaccine’s efficacy and safety confirm that it will be highly effective against COVID-19 and will have an immediate impact on this public health emergency. Furthermore, the vaccine’s simple supply chain and our no-profit pledge and commitment to broad, equitable and timely access means it will be affordable and globally available, supplying hundreds of millions of doses on approval.”

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