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- The UK has licensed the Oxford-AstraZeneca Covid-19 vaccine for public use
- More than 2.5 billion doses have been ordered worldwide.
- Implementation is scheduled to begin in the first week of 2021
The UK has become the first country to authorize the Oxford-AstraZeneca Covid-19 vaccine for public use, and its rollout will begin in the first week of 2021.
This vaccine is the second to be licensed in the UK, after the Pfizer vaccine.
The British government has ordered 100 million doses of the Oxford vaccine, enough to vaccinate 50 million people.
Other countries will be watching closely: Australia has ordered more than 50 million doses, Canada 20 million, and more than 2.5 billion doses have been reserved worldwide.
AstraZeneca expects to be able to deliver a large number of doses during the first quarter of 2021.
In particular, the British will receive two full doses of the vaccine, which in trials prevented people from getting sick with Covid-19 62% of the time.
This is despite the fact that the trials initially suggested that an alternative dosing strategy, using half a dose followed by a full dose, could be much more effective, preventing disease 90% effectively.
How important is the Oxford vaccine now available? The Conversation asked Michael Head, a global health expert at the University of Southampton, some key questions about why his authorization is important.
Why is this vaccine needed?
The least happy Christmas in recent times has at least had the silver lining in a highly effective vaccine, the Pfizer, available and licensed for use in the UK.
But despite the brilliance of this magic bullet, there are limiting factors, particularly around the scale of production required to meet demand.
Demand for the Pfizer vaccine in several countries is similar to a very busy hour when the local supermarket just rolled out some new delivery slots during closing, and you are racing to reserve the order before any of your neighbors do. notice.
Everyone wants to go in first to ensure delivery of the last package of toilet paper or, in this case, the next batch of vaccines.
The difficult logistics of storing and transporting Pfizer vaccine at ultra-low temperatures is also restricting the speed of the national launch of the vaccine.
So we need several candidate vaccines to come close to meeting demand, and we need them quickly.
Having the Oxford vaccine available could go a long way in speeding up coverage, particularly as in the UK the priority has shifted to getting a first dose of vaccine for as many people as possible.
However, there are still gaps in our knowledge, for example around the effectiveness of this vaccine in the elderly, and also whether leaving a longer gap between doses increases overall effectiveness, as has been suggested.
How is this vaccine different?
The three main vaccines deliver some of the coronavirus’ genetic material to cells in the body, leading the cells to produce copies of part of the virus, the spike protein, against which the body can mount an immune response.
The Oxford vaccine performs this delivery using an adenovirus vector, while the Pfizer and Moderna vaccines use an mRNA platform.
Previously published data indicated an overall efficacy of 62% if two doses of the Oxford vaccine are given, which is less than 94% of the Moderna vaccine and 95% of the Pfizer vaccine.
But it was thought that giving a small dose first and then a second full dose might be more effective.
With this dosing strategy, limited data from the phase 3 trial indicated an efficacy in younger populations of around 90%.
However, the UK Medicines and Healthcare Products Regulatory Agency has said that the results of this half-dose and full-dose regimen were “not confirmed by a full analysis” when it conducted its review, so further investigation will be needed. of this regime.
But the UK Commission for Human Medicines now suggests that one dose provides 70% protection after 21 days, and that a second dose potentially increases effectiveness to around 80%, but that the second dose should be given 12 weeks later. from the first.
However, the data showing this has yet to be published.
As has been documented, Oxford’s vaccine only needs to be kept at a cold temperature, while Pfizer’s requires storage of -75 ° C and Moderna’s should be kept around -20 ° C.
This would facilitate the management and distribution of all countries, but especially for low- and middle-income countries.
In sub-Saharan Africa or Southeast Asia, healthcare colleagues are highly adept at getting vaccines to hard-to-reach populations, but they simply don’t have the infrastructure in place to ensure ultra-low temperatures can be maintained.
What does this mean for the world?
At US $ 2-3 per injection, the cost per dose of the Oxford vaccine is much cheaper than that of the other leading vaccines, making it a potential long-term option for governments when the world has passed the point to spend whatever it takes to get the coronavirus under control.
Global orders for this vaccine far exceed those of the others.
The Oxford vaccine is being manufactured in Europe and also in large numbers in India, and is part of the COVAX initiative, led by Gavi, the Vaccine Alliance, so it may be the first vaccine developed in the West to be implemented in large quantities in low- and middle-income countries sometime in 2021.
Read more: Why the Oxford AstraZeneca vaccine is now a global game changer
However, it will be interesting to see how the vaccines developed by Russia and China are distributed internationally.
China has invested heavily in healthcare across the African continent, and the balance between altruism and opportunism is unclear.
While we would love for this global public health problem to be treated simply as a public health problem, it is quite possible that we will see vaccines being used as capital to develop new political relationships or to reaffirm existing ones.
Some vaccines may be favored ahead of others in some parts of the world due to political influence.
The global deployment of vaccines will be incredibly complex and a variety of factors will inevitably contribute to its success.
To know the impact of the Oxford vaccine, we will have to wait and see. Yet amid the intense gloom of 2020, having multiple effective candidate vaccines available bodes well for 2021.
Michael Head, Senior Researcher in Global Health, University of Southampton. This article is republished from The conversation under a Creative Commons license. Read the Original article.
