The UK government took the first step in that approval process on Friday, announcing that it had formally referred the candidate to the UK drug regulator for evaluation.
“[T]The Pfizer vaccine is committed to its starting doses for the EU and the US, and Moderna’s supply will be tied to the US for at least probably the first half of 2021, so in light of that , the Oxford / AstraZeneca vaccine is really good news for the rest of the world, “Andrea Taylor, deputy director of programs at Duke Global Health Innovation Center, told CNN.
AstraZeneca has promised to supply hundreds of millions of doses to low- and middle-income countries and to deliver the vaccine nonprofit to those nations in perpetuity. The vaccine developed at the University of Oxford in England is significantly cheaper than the others and, more importantly, it would be much easier to transport and distribute in developing countries than its rivals, as it does not need to be stored at low temperatures. zero.
“I think it is the only vaccine that can be used in those settings right now,” Azra Ghani, chair of infectious disease epidemiology at Imperial College London, told CNN.
Oxford / AstraZeneca vaccine can be stored at a refrigerator temperature of 2 to 8 degrees Celsius for at least six months. Moderna’s vaccine should be stored at -20 ° C, or refrigerator temperature for up to 30 days, and Pfizer / BioNTech vaccine should be stored at -75 ° C and used within five days of being refrigerated at higher temperatures.
“Pfizer and Moderna require freezer storage, and that’s just not in place in many settings,” Ghani said.
“Cold chain” refrigeration is the standard storage used globally to deliver vaccines from central locations to local health clinics. AstraZeneca’s vaccine is so far “the only one that can definitely be delivered to those systems,” Ghani added.
Vaccines are based on different technologies. AstraZeneca’s offering, like the Johnson & Johnson vaccine and Russia’s Sputnik V, uses an adenovirus to transport coronavirus gene fragments into the body.
The Moderna and Pfizer vaccines use pieces of genetic material called messenger RNA (mRNA) to drive the body to produce synthetic pieces of the coronavirus and stimulate an immune response. “This is a relatively new technology and little is known about the stability of mRNA over time,” Penny Ward, chair of the Education and Standards Committee at the UK College of Pharmaceutical Medicine, told CNN.
He said that as Moderna and Pfizer accumulate information and manufacturing capacity, they may be able to find storage methods at higher temperatures, but the Oxford vaccine “has the potential to be able to be shipped more easily around the world” using the chains of existing supply. .
However, it will only be of value if the efficacy levels of the vaccine are maintained while it is distributed in developing countries.
AstraZeneca said this week that trials showed that one dosing regimen produced 62 percent efficacy while the other reached 90 percent, averaging 70 percent. This is a good result, comparable to the flu shot, but not as high as 95 percent from Pfizer and 94.5 percent from Moderna. The 90 percent figure is based on a sample of 2,741 participants, which is a relatively small number.
Moncef Slaoui, senior advisor to the US government’s Operation Warp Speed, said this week that there were “a number of variables that we need to understand” surrounding the dose and age differences in the Oxford / AstraZeneca results. , after which the ongoing US trial may need to be modified.
On Thursday, an AstraZeneca spokesperson told CNN that they were currently in discussions with the FDA about including the half-potency dose regimen in their US trials, which currently have about 10,000 participants.
Ayfer Ali, associate professor of international business at Warwick Business School, said the “simplicity of distribution” of the AstraZeneca vaccine could “possibly compensate for the lower potential efficacy.”
“The actual efficacy of mRNA vaccines that are more fragile to transport and store may be lower in real-world conditions where correct storage of each dose can be difficult to verify,” he added.
BioNTech said last week it was working with Pfizer to find a formula that would allow its vaccine to be stored at standard temperatures by the second half of 2021. Moderna this month extended its estimate of how long its vaccine could remain stable at refrigerator temperature. from an estimated seven to 30 days. This, according to Moderna’s technical director of operations and quality, Juan Andrés, “would allow easier distribution and greater flexibility to facilitate vaccination on a larger scale in the United States and other parts of the world.”
AstraZeneca has pledged 300 million doses of its vaccine to COVAX, a partnership between GAVI, the vaccine alliance; World Health Organization; and the Coalition for Epidemic Preparedness Innovations (CEPI) to ensure equitable distribution in 92 developing countries. The only other known vaccine developer that has made a promise of a similar scale is Sanofi, at 200 million doses.
A representative for GAVI told CNN that the Serum Institute of India (SII) and the Bill and Melinda Gates Foundation would also provide up to 200 million doses of the AstraZeneca and / or Novavax candidate vaccines to low-income countries. Moderna and Pfizer have not promised any doses to COVAX.
This could mean that AstraZeneca has more manufacturing capacity than other pharmaceuticals thanks to its ties to industry giants such as SII through CEPI.
“[AstraZeneca has] been working with manufacturing experts in that coalition to help source a variety of different manufacturing sites and of course it’s not just about the vaccine itself, but also the glass vials it goes into, the stoppers that They go on top of the vials and the syringes and needles, “Ward said.
AstraZeneca says it expects to have the capacity to produce up to 3 billion doses of the vaccine in 2021 on a continuous basis. Pfizer / BioNTech says it can make up to 50 million doses in 2020 and 1.3 billion in 2021, while Moderna says it hopes to be able to deliver approximately 500 million doses per year and possibly up to 1 billion doses per year starting in 2021.
Following calls for transparency from groups such as Medicins Sans Frontieres and Global Justice Now, AstraZeneca and Oxford confirmed that the association would deliver the non-profit vaccine until at least July 2021 worldwide, and in perpetuity for the low-income. and media. countries.
The Oxford vaccine is cheaper than the others, roughly US $ 3 to US $ 4 ($ 4 to $ 6) per dose, in contrast to roughly US $ 20 ($ 27) for the Pfizer vaccine and US $ 32-37 ($ 43-50) for the Moderna vaccine. .
“Our vaccine can be rapidly deployed in existing healthcare settings, which will help stop the spread of this disease while we learn more and more about how to prevent and treat it,” a spokesperson for the University of Oxford told CNN. He added that a variety of vaccines would be needed and some might be more effective for different ages and populations.
“The key to any vaccine is the potential for public health impact, including how quickly it can be distributed. Ours can be quickly and easily distributed around the world, using existing logistics, and can be easily stored in a refrigerator, “he said.
COVAX will be instrumental in bringing the vaccine to low- and middle-income countries, the Duke University model shows. The initiative aims to provide 2 billion doses by the end of 2021 to protect high-risk groups around the world and eventually enough doses to cover 20% of the population of those countries.
However, Ghani cautioned that 20 percent “is not close to the ideal, about 70 percent, that we would like to see in order to achieve herd immunity, so some countries will still fall short.”
He said that it is vital for everyone that the world population is vaccinated, to allow travel and movement across borders. The launch of the vaccine in the world could take until 2023, according to current models, not to mention the possible need for booster vaccines.
Duke’s model shows that while the richest countries have bought billions of doses in advance to increase their chances of covering their populations, the developing world will be completely dependent on COVAX.
Bill Gates said the solution “was not to shame rich countries that are doing the natural thing to want to protect their people,” but to massively increase manufacturing capacity.
Stephen Evans, professor of pharmacoepidemiology at the London School of Hygiene and Tropical Medicine, warned that monitoring efficacy and safety issues would be an ongoing challenge in the developing world.
“There may be some adverse effects that would only be apparent in those low- and middle-income countries – they have different diets, they have different levels of nutrition in general and different characteristics,” he told CNN.
While the Oxford vaccine may be particularly promising at this stage in helping low-income countries, there are still many caveats about the data that need to be resolved before it can be implemented.
Ultimately, it will be vital to have as many vaccines as possible, to ensure a faster recovery and limit further damage to the world.