As of Saturday, the United States has surpassed more than 12 million Covid-19 cases and over 255,000 deaths since the pandemic began. Pharmaceuticals around the world have been racing to develop an effective vaccine, as the U.S. sees more than 200,000 new cases on Saturday alone.
Astra Zeneca has been giving the world hope for many years and now they join the Coronavirus (COVID-19) battle and have announced they have a vaccine that has been showing signs of effectiveness of up to 90%.
Two different dosing regimens demonstrated efficacy with one showing a better profile
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 hospitalizations 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.
With the Pfizer-BioNTech and Moderna vaccines achieving efficacy of around 94%, the bar was set high for AstraZeneca’s AZD1222. Overall, the COVID-19 vaccine, which AstraZeneca has developed with the University of Oxford, fell well short of that bar. However, compared with the other candidates, the details offer encouragement that the vaccine is highly effective.
The 70% efficacy figure is the average result for two regimens given to 11,636 people. Most subjects, 8,895, received the same dose for their first and second jabs. A smaller cohort, 2,741 subjects, got a half dose for the first jab followed by a full booster shot.
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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%. All results were statistically significant.
An independent Data Safety Monitoring Board 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. AZD1222 was well tolerated across both dosing regimens.
“One potential explanation for this is that the body is mounting an anti-vector immune response to the second dose, which is lower if the first dose is reduced; such an immune reaction could reduce the efficacy of the vaccine,” Gillies O’Bryan-Tear, chair of policy and communications for the Faculty of Pharmaceutical Medicine, said in a statement
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. In parallel, the full analysis of the interim results is being submitted for publication in a peer-reviewed journal.
No hospitalizations or severe cases of COVID-19 in participants treated with AZD1222
Professor Andrew Pollard, Chief Investigator of the Oxford Vaccine Trial at Oxford, 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 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.”
Pascal Soriot, Chief Executive Officer, 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.”
The global trials are evaluating participants aged 18 years or over from diverse racial and geographic groups who are healthy or have stable underlying medical conditions.
Clinical trials are also being conducted in the US, Japan, Russia, South Africa, Kenya and Latin America with planned trials in other European and Asian countries. In total, the Company expects to enroll up to 60,000 participants globally.
The Company is making rapid progress in manufacturing with a capacity of up to 3 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.
AstraZeneca continues to engage with governments, multilateral organizations and collaborators around the world to ensure broad and equitable access to the vaccine at no profit for the duration of the pandemic.
“We believe that this product will never be licensed in the U.S. This belief is based on the design of the company’s pivotal trials (which does not appear to match the FDA’s requirements for representation of minorities, severe cases, previously infected individuals and elderly and other increase risk populations), and based on the occurrence of severe safety events (why take the risk) that resulted in the extended clinical hold on enrollment into the trials in the U.S.,” the analyst wrote.
Shares in the Big Pharma were off nearly 1.5% in London trading Monday morning, showing just how high the bar for a COVID-19 vaccine now is and how complex the picture for its efficacy remains.
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COV002 is a single-blinded, multi-center, randomized, controlled Phase II/III trial assessing the safety, efficacy and immunogenicity of AZD1222 in 12,390 participants in the UK. Trial participants to date are aged 18 years or over, who are healthy or have medically stable chronic diseases and are at increased risk for being exposed to the SARS-CoV-2 virus. Participants receive one or two intramuscular doses of a half dose (~2.5 x1010 viral particles) or full dose (~5×1010 viral particles) of AZD1222 or comparator, meningococcal vaccine MenACWY.
Participants have blood samples drawn and clinical assessments for safety as well as immunogenicity at multiple timepoints up to one year post-vaccination. Suspected cases presenting with compatible symptoms were tested for virological confirmation by COVID-19 PCR. In addition, weekly swabbing are done for detection of infection and assessment of vaccine efficacy against infection.
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COV003 is a single-blinded, multi-center, randomized, controlled Phase III trial assessing the safety, efficacy, and immunogenicity of AZD1222 in 10,300 participants in Brazil. Trial participants to date are aged 18 years or over, who are healthy or have medically stable chronic diseases and are at increased risk for being exposed to the SARS-CoV-2 virus.
Participants are randomized to receive two intramuscular doses of a full dose (~5×1010 viral particles) of AZD1222 or comparator, meningococcal vaccine MenACWY as first dose and a saline placebo as second dose. Participants have blood samples drawn and clinical assessments for safety as well as immunogenicity at multiple timepoints up to one year post-vaccination.
Suspected cases presenting with compatible symptoms were tested for virological confirmation by COVID-19 PCR.
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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.
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