Why is the Oxford Astrazeneca vaccine a global exchanger?

In the long dark tunnel that was in 2020, November stands out as the month that appeared light. Some may see it as a bright light, others as a dim light – but it is unmistakably a light.

On November 9, the Pfizer the interim results announced of its candidate vaccine, which shows that it is “more than 90% effective” in preventing symptomatic COVID-19 in the late stages of human trials. The news was greeted with joy.

A a few days later, the Russian Direct Investment Fund announced that the candidate vaccine they are financing – called Sputnik V – has shown 92% efficiency in late-stage trials. Not to be outdone, Moderna then announced that the candidate vaccine showed 94.5% efficacy.

The latest COVID-19 vaccine announcement comes from the University of Oxford. And as with all of the above announcements, it comes via Press release. The vaccine candidate, developed in partnership with AstraZeneca, showed an overall efficacy of 70.4%.

If this sounds disappointing, keep in mind that these are intermediate results and that the figures may change. The Oxford vaccine was also given to one group of volunteers as two standard doses, which showed 62% efficacy, and another group of volunteers as a smaller dose followed by a standard second dose. This increased the efficiency to 90%.

It is not immediately clear why this is the case. Professor Andrew Pollard, one of the main researchers of the project, describes the results as “intriguing”. He also stressed that using lower doses means that more vaccine doses will be available.

There were no cases of severe COVID-19 in those who received the vaccine. And it seems to elicit a protective immune response in older people. Although we have to wait until the final outline of the results to get clarity on it.

Effectiveness is not the only measure

Despite the fact that the Oxford vaccine has a lower effectiveness than the Pfizer or Moderna vaccines – at least at this interim stage – there are other success factors to consider. Safety is one, and the Oxford vaccine so far has a good safety record with no serious side effects.

Another important factor is storage. The Oxford vaccine can be stored in a refrigerator. The need for continuous freezing Throughout the entire vaccine journey from factory to clinic at ultra-low temperatures – as seen with the Pfizer vaccine – this can be a problem for many countries, but especially for poorer countries.

The Oxford vaccine, based on a viral vector, is also cheaper (approximately US $ 4) as Pfizer and Moderna’s mRNA vaccines – US $ 20 and $ 33 respectively. AstraZeneca has ano profit promise“.

Equitable distribution

As I have previously discussed, equitable distribution of new vaccines is crucial, especially for low- and middle-income countries that do not have the profile or purchasing power of rich countries. GAVI – a global health partnership aimed at increasing access to vaccination in poor countries – has been working on this for years. It sets the COVAX initiative in 2020, which has access to 700 million doses of COVID vaccine if clinical trials are successful.

Oxford and AstraZeneca made it before their own obligations to deliver one billion doses of their vaccine to low- and middle-income countries, with the commitment to give 400 million doses before the end of 2020. AstraZeneca has definitely committed to increasing doses to outside countries Europe and the USA than any of its closest competitors.

An excellent start

These commitments will clearly not be sufficient for immediate global coverage, but they are an excellent start. About 9% of the world’s population living in extreme poverty, and the health systems around them are fragile. With promises of equitable distribution of vaccines, there is hope that the poorer populations around the world will not be forgotten. The global health community needs to focus on this area.

What does this announcement mean for the world? Potentially a large amount. However, keep in mind that the trials have not yet been completed, and at the time of writing, regulators have yet to approve any of the new vaccine candidates. Even when these obstacles are removed, we still need to vaccinate the world, which must successfully navigate the complex obstacles of distance, terrain, politics, cold chain logistics and human behavior.

The global pandemic is not over yet and will not be for long – but the light is getting brighter and brighter.

Michael Head, Senior Research Fellow in Global Health, University of Southampton


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