AZD1222 was well tolerated with no confirmed serious safety events and offered protection from Covid-19 after 14 days of receiving two doses
AstraZeneca’s Covid-19 vaccine is up to 90% effective. (Credit: pearson0612 from Pixabay.)
AstraZeneca has announced positive results from an interim analysis of clinical trials of its investigational Covid-19 vaccine AZD1222, conducted in the UK and Brazil.
In the clinical trials, the vaccine has met the primary endpoint of effectiveness in preventing Covid-19, with no hospitalisations or disease severity reported.
The interim analysis included a total of 131 Covid-19 cases from COV002, a Phase 2/3 trial in the UK and COV003, a Phase 3 trial in Brazil.
One of the two-dose regimens, given as a half dose followed by a full dose at least one month apart, showed 90% vaccine efficacy. Another dosing regimen, given as two full doses at least one month apart, showed 62% efficacy.
AZD1222 was well tolerated across both dosing regimens with no confirmed serious safety events, showing an average of 70% efficacy from combined analysis of both dosing regimens.
According to the independent Data Safety Monitoring Board, the vaccine offered protection from Covid-19 after 14 days of receiving two doses.
Oxford Vaccine trial chief investigator Andrew Pollard 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 maybe 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.”
The global trials COV002 and COV003 are evaluating participants aged 18 years and above, who are racially and geographically diverse, with stable medical conditions.
The company is also conducting clinical trials in the US, Japan, Russia, South Africa, Kenya and Latin America with planned trials in other European and Asian countries.
Developed by the University of Oxford and its spin-out company Vaccitech, AZD1222 leverages a replication-deficient chimpanzee viral vector based and contains the genetic material of the SARS-CoV-2 virus spike protein.
AstraZeneca is planning to apply with the global regulatory authorities, for conditional or early approval, and the company will seek an Emergency Use Listing from the World Health Organization for effective distribution of the vaccine in low-income countries.
The surface spike protein is produced after vaccination, stimulating the immune system to attack the SARS-CoV-2 virus in case of the later infection.
The vaccine is capable of being stored, transported and handled at normal refrigerated conditions for at least six months, and can be administered in existing healthcare settings.
AstraZeneca chief executive officer Pascal Soriot said: “Today marks an important milestone in our fight against the pandemic. 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.”