AstraZeneca / Oxford covid-19 vaccine is cheap and easy to store, but it is growing, especially in terms of side effects.
These are some of its main features:
– “Viral vector” –
This vaccine was developed by researchers at Oxford University in collaboration with the British pharmaceutical giant AstraZeneca.
It is a “viral vector” vaccine: it is based on another virus (a chimpanzee adenovirus) that has been weakened and genetically modified to prevent the reproduction of the coronavirus in the human body.
The way he introduces genetic material into cells, ordering them to attack SARS-CoV-2, has been called the “Trojan horse”.
– Practical and affordable –
The AstraZeneca / Oxford vaccine has the advantage of being cheap (about 2.5 euros or $ 3 per dose, with variations depending on local production costs). AstraZeneca agreed to sell it without making a profit.
It is also easy to store: it can be stored at 2 ° C to 8 ° C, unlike Moderna and Pfizer / BioNTech vaccines, which can only be stored for a long time at very low temperatures.
This facilitates large-scale vaccination.
This drug is also distributed through the Covax program to the most disadvantaged countries.
– Questions about side effects –
There are suspicions about possible serious but rare side effects after detecting atypical cases of thrombosis in patients vaccinated with AstraZeneca.
Dozens of cases have been reported, some of which have resulted in deaths.
The UK has reported 30 cases and seven deaths so far, out of a total of 18.1 million doses administered since March 24. No similar observations were reported after application of millions of doses of Pfizer / BioNTech.
According to the European Medicines Agency (EMA), “no causal relationship has been proven, but it is possible”, and the benefits of the immunavirus against coronavirus continue to outweigh the risks.
As a precaution, several countries have decided not to administer this vaccine under a certain age, such as Germany and the Netherlands (60 years), France and Canada (55 years), or Sweden and Finland (65 years).
For its part, AstraZeneca said in March that “there is no evidence of an aggravated risk.”
– Confusion about its effectiveness –
According to the British laboratory, it has an average efficiency of 70% (compared to over 90% for Pfizer / BioNTech and Moderna), a result validated by the scientific journal The Lancet.
In the first published results, from clinical trials prior to their approval, there were variations in efficacy, depending on the different doses administered by mistake, which sowed doubts and provoked criticism, leading the company to conduct additional studies.
Its effectiveness in people over the age of 65 has also been questioned in Europe due to a lack of data, until new information, extracted from the vaccination campaigns of the most advanced countries in this field, provided assurance in this regard.
In the United States, the drug regulator has criticized the pharmaceutical group for providing “outdated” data in its clinical trials. Therefore, it reduced its effectiveness to 76% in symptomatic cases, instead of 79%.
Two real-world British studies in Scotland and England have shown significant protection against hospitalization.
– Delays in deliveries –
According to AstraZeneca, in mid-March, the vaccine was approved in more than 70 countries. The United Kingdom was the first to authorize it and ordered 100 million doses.
Delays in remittances to European Union countries have sparked strong complaints, as the laboratory has delivered the promised stocks to the UK. Faced with this lack of supply, the European Commission has decided to control exports of vaccine vaccines to prevent deliveries to other countries.
This situation has provoked tensions between Brussels and London, but since then they have promised to resolve the dispute through negotiations.