The University of Oxford and AstraZeneca vaccine against Covid-19 has met with reluctance from some groups in Europe, who consider it less effective, but with the available data it is not possible to speak of better or worse formulas, in addition to all the approved they are safe and effective.
This is what King’s College London’s Department of Infectious Diseases researcher, José Manuel Jiménez Guardeño, tells Efe, for whom “the most important message that can be given is that the best vaccine is given first. This is not the time to choose ”.
Virologist Santiago Elena, of the Institute for Integrative Systems Biology at the CSIC, refers to the World Health Organization (WHO) last day 21 report to say that “there is no difference” between Pfizer preparations, Modern and Oxford / AstraZeneca.
The minimum age is 18 and there is no maximum age to receive them, ‘all three are just as good’ for pregnant women, ‘there are no problems for breastfeeding mothers, they can be given’ with the same peace of mind ‘to people with a compromised immune system, who have HIV or who have already had covid-19, lists.
In parts of Europe, however, there are voices that the Anglo-Swedish company does not want. Some German health workers and other groups have shown their reluctance and in Berlin, where there is freedom of choice, the majority prefer the preparation of BioNTech / Pfizer or Moderna.
In Austria, hundreds of health workers at the AKH University Clinic in Vienna signed an “online” petition mid-month to change the vaccination plan and receive Pfizer’s plan, which they say is more effective. Something similar has happened in other regions of the country, such as Salzburg or Styria.
The main reason for this questioning in several countries is the assumed lower effectiveness. Pfizer and Moderna vaccines are 95% and Oxford / Astrazeneca is about 60-70% when both doses are given.
“When you look at these results, it might seem like the former are much more effective. However, this is not as clear as those results are not very comparable. The reason is that every clinical trial is different and uses different age groups and criteria,” Jiménez indicates.
Now it appears that delaying the second dose of the AstraZeneca vaccine increases its effectiveness, he points out, so “it is too early to make comparisons” and we have to wait to see the effects of the vaccination in “real life”. to see.
Elena explains that talking about 70% protection “doesn’t mean that out of every 100 people who receive it, 30 will be left naked.”
Vaccines are a complex topic involving many factors, they are ‘complicated data’ that often ‘require those of us involved to read it twice, as if they wanted to explain it in 30 seconds of the news’.
Another argument is that the British development preparation would be less effective against the South African variant, in fact that country has decided not to apply it for the time being, but these are “still very preliminary studies and with a very small sample,” says Jiménez. .
In the event that it is true that “the protection is limited against any of the new variants, the vaccines should simply be updated, which is a fairly simple and quick process to perform”.
In addition, this vaccine is not recommended in some European countries for people over 65 or 55 years old, depending on the location. Elena points out that because there were not enough people over the age of 55 in the studies, “this was a defect in the sample design,” so, says Jiménez, “there is currently insufficient data to evaluate its effectiveness. “.
What applies, says Elena, “is always the principle of maximum precaution,” and since there were not enough elderly people in the trial, some countries are careful not to vaccinate them with AstraZeneca, as others are available.
There are also people who show their reluctance because the University of Oxford vaccine is more likely to cause mild reactions after administration, but according to Jiménez they are “very similar” to the rest.
Looking at the first dose, “it may seem that the effects of the Oxford / AstraZeneca vaccine are more frequent and perhaps more intense, but this is because it uses a viral vector instead of messenger RNA,” which is what Pfizer’s technology means. is and Modern “.
Jiménez points out, however, that based on what he has seen, the second dose of Pfizer or Moderna “tends to have stronger effects than the first and, in the case of Oxford / AstraZeneca, milder.
In addition, Elena emphasizes, the latter “even has an advantage” for those with a history of allergies or severe anaphylactic reactions, as it does not contain the adjuvants that the other two do, as they are based on messenger RNA, that would ” may cause a reaction “.
The AstraZeneca also has “the advantage of being infinitely simpler in transportation and logistics” because – he adds – it is stored in a fridge at four degrees, not the -20 that Moderna or -80 from Pfizer requires.
Based on “objective criteria, there is no justification” for rejecting the AstraZeneca vaccine, emphasizes Elena, who believes more could come of the sociological part of seeing how the company has struggled to meet the delivery times it has. with the European Union.
AstraZeneca CEO Pascal Soriot said in Brussels yesterday that the company hopes to “catch up” its contractual obligations to the European Union for the supply of vaccines in the second quarter of this year.
Both experts stress that all approved vaccines are “safe and work” and that now is not the time to choose. When we get the flu, Jiménez recalls, “ we don’t ask which ones they did to us, whether it’s based on inactive virus or subunits, what strains of influenza it uses, the brand or the efficacy, and yet the benefit is more than obvious. “.
Elena emphasizes that we are dealing with a public health problem and most importantly, there is “the greatest possible group protection and that is achieved with all vaccines.”