The vaccine developed by the British pharmaceutical AstraZeneca and the University of Oxford became the third approved in Europe at the end of January, after the European Medicines Agency confirmed receipt of the application.
European authorities and national governments are under a lot of pressure to accelerate supply and vaccination campaigns and AstraZeneca’s vaccine, cheap to produce and easy to transport, could be key in the face of logistical difficulties posed by Pfizer’s vaccine. and to a lesser extent that of Moderna, and the high price of both. One dose of the AstraZeneca vaccine costs about € 6. That of Moderna, ten times more and that of Pfizer / BioNTech € 33.
It is also kept in a domestic refrigerator, without the need for the -18º C required by Moderna’s vaccine or the -70º C needed to store Pfizer vaccines.
According to the first results, it could reduce transmission by reducing asymptomatic infections. In contrast, Pfizer and Moderna vaccines are more effective in reducing severe cases of COVID-19.
Having approved the vaccine and started to use it before Christmas, the British National Health Service NHS has published the package leaflet with the list of components. It may not be the complete list but they are the ingredients most likely to cause reactions.
Genetically modified chimpanzee cold adenovirus
The main ingredient in the AstraZeneca and Oxford University vaccine is a chimpanzee cold-causing adenovirus, genetically modified so that it cannot develop and reproduce in our bodies.
Adenoviruses are a very common family of viruses that cause various pathologies in both humans and animals.
At first, it doesn’t sound very attractive, but this technology has been in development for years – while the synthetic messenger RNA from Pfizer and Moderna is completely new – and it is much more stable than its competitors.
The University of Oxford and AstraZeneca vaccine also reproduces, like the other two vaccines, the genetic sequence of the new coronavirus protein S, the spike that the virus uses to invade our cells.
The immune system receives the information and learns to defend itself against COVID-19 when exposed by creating neutralizing antibodies and a response from the immune system’s T cells.
Amino acids, salts and other excipients
Most of the rest of the ingredients are quite common. Unlike the Pfizer and Moderna vaccines, it does not require lipids for preservation.
– L-Histidine. It is an essential amino acid that we consume daily in food.
– L-histidine hydrochloride monohydrate. Another chemical form of this amino acid.
– Magnesium chloride hexahydrate. A very common type of salts
– Polysorbate 80. A thickening additive present in drugs and cosmetics that has an action on fats
– Ethanol (alcohol)
– Saccharose (sugar)
– Sodium chloride (common salt, table)
– Ethylenediaminetetraacetic acid (EDTA). It is used as an additive in food and medicine to remove heavy metals, as an anticoagulant, and is also used to prevent bacteria from forming biofilms. It has antimicrobial properties.
– Water for injections
Errors in the report of clinical analyzes
The AstraZeneca and Oxford team caused some shock and surprise by publishing that due to a dosage error, the vaccine was more effective in patients who received only half a dose in the first injection and a full dose in the second. According to the president of AstraZeneca, new tests have been carried out and similar results have been reached by inoculating 100% of the dose in the two necessary injections.
In terms of side effects, this vaccine is similar to or even better than Moderna and AstraZeneca. Around 60% of patients report sensitivity in the puncture area, 50% pain in the injection area, headache or fatigue, 40% muscle pain or discomfort, 30% chills or high temperature, 20% % joint pain and nausea. In general, they are mild symptoms that pass within a few days. As with the other two vaccines, it seems that older adults cope better than younger ones.
AstraZeneca conducted clinical trials with just over 23,000 patients.
AstraZeneca makes its vaccine available without making a profit, but it has created controversy by stating that this is for the duration of the pandemic and reserves the right to declare the end of the pandemic in July 2021. However, given the controversy, the pharmaceutical company specified that its vaccine will be affordable “perpetually” for developing countries.
The University of Oxford and AstraZeneca collaborate with the United Nations COVAX program to guarantee access to vaccines in the countries with the most difficulties.