Oxford-AstraZeneca’s Covid-19 vaccine: Five things to know

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  • The Covid vaccine developed by Oxford University and AstraZeneca incorporates established technology, compared to vaccine frontrunners using mRNA technology
  • The vaccine is also best suited for certain countries like SA, says Professor Shabir Madhi
  • This is due to several reasons, including cost and vaccine access

The Covid-19 vaccine (ChAdOx1 nCoV-19), developed by the University of Oxford and drugmaker AstraZeneca, was found to be successful in late-stage studies. We’ve rounded up five facts on why this vaccine is considered the global gamechanger in the fight against Covid-19.

The only clinical trial to have results published in a medical journal

Oxford University and AstraZeneca became the first major Covid-19 vaccine developers to publish final-stage clinical trial data in a prestigious scientific journal this week, Health24 reported.

Although early data of the other frontrunner vaccines developed by Pfizer and BioNTech (BNT162b2), as well as Moderna (mRNA-1273) have shown efficacy of 90% or higher, the results were shared in a press statement, and a full assessment cannot be made just yet, Professor Thomas Scriba (deputy director of immunology and laboratory director at the South African Tuberculosis Vaccine Initiative, University of Cape Town) previously told Health24

Speaking about the importance of publishing data in peer-reviewed medical journals, Scriba explained that it “allows true scrutiny of the results, which is important because every clinical trial is subject to certain limitations, interpretation nuances and complications, and information about these is currently not available”.  

It incorporates established vaccine technology

The Oxford-AstraZeneca vaccine is based on a different technology to Pfizer-BioNTech and Moderna’s vaccines.

The Oxford vaccine is based on familiar technology – a kind of chimpanzee cold virus, called an adenovirus-vector technology, that has been used in experimental vaccines given safely to thousands of people for diseases ranging from TB and malaria to Mers and Ebola, notes the Guardian. Scientists quickly modified the platform to a Covid-19 vaccine.

The other two vaccines, however, use genetic material called mRNA, or messenger RNA, which tells human cells how to make coronavirus spike proteins. This technology is new to the vaccine field and has received approval by regulators for the first time.   

It’s the easiest to store

Storage of Pfizer-BioNTech’s mRNA vaccine is challenging for many countries, including South Africa, as it needs to be stored and transported at below-freezing temperatures – minus 70 degrees Celsius to be exact. If this isn’t applied, the vaccine can be damaged and become less effective.

Unfortunately, South Africa’s public and private health sector doesn’t have the required facilities to store this vaccine, except for a few at large academic institutions such as the National Institute for Communicable Diseases, Bhekisisa previously reported.

Similarly, Moderna’s mRNA-1273 jab is likely to pose a problem to SA, as it needs to be stored at minus 20 degrees Celsius.

Unless these formulations are reworked, it is unlikely that these vaccines will reach South African shores.

Oxford-AstraZeneca’s vaccine, however, is easier to transport and store as it can be stored at fridge temperatures of 2–8 degrees Celsius.

It’s the cheapest of the three frontrunners

The Oxford jab is also far cheaper than the Pfizer-BioNTech and Moderna vaccines as the technology is more established, making it easier for the vaccine to be mass-produced.

Pfizer-BioNTech’s vaccine is reportedly $20 per dose, while Moderna said in August it is charging between $32 and $37 per dose and might offer a discount if bought in bulk.

The Oxford-AstraZeneca vaccine, on the other hand, has the lowest price at $3–$4 (approximately R30 to R45) per dose and has a longer shelf life compared to the other two vaccines.

Access to Oxford vaccine easiest for countries like SA

Pfizer has said that it should have 50 million doses by the end of 2020, and these will be split between the US and other countries that made advanced purchase agreements, reports Science Magazine.

Moderna also hopes to provide the US government with 20 million doses by the end of the year. According to Shabir Madhi, Professor of Vaccinology at Wits University, this low number is due to the complexity of the manufacturing of the mRNA technology in their vaccines. Madhi was speaking at a virtual webinar hosted by MyHealthLIVE on Wednesday.

To put it into context, he added that AstraZeneca has established up to 10 manufacturing facilities and has indicated that by the end of 2020, they will be able to produce 200 million doses of vaccine, and three billion by the end of 2021.

“Pfizer and Moderna combined are expected to produce two billion doses of vaccine by the end of 2021,” said Madhi.

The vaccine best suited to be deployed in South Africa, based on cost and time, is therefore most likely going to be the Oxford-AstraZeneca vaccine, said Madhi.

As to when exactly South Africa will get the vaccine, that largely depends on the government, explained Madhi:

“It depends on their engagement, either through the COVAX Facility, or through both the COVAX Facility and bilateral agreements that it needs to enter into with AstraZeneca and any other manufacturer of Covid-19 vaccines that have been proven to be safe and efficacious.” 

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