Covid: AstraZeneca admits its vaccine may have “a rare side effect” | He did so within the framework of an inquiry taking place in Great Britain

AstraZeneca has admitted before a British judge that its vaccine against Covid-19 could cause “a rare side effect”.. The approval comes amid a class action lawsuit launched in that country against the drug company due to adverse effects in a small number of cases from uses during the 2020 pandemic.

Although the pharma company has already pointed out the possibility of this adverse effect occurring in extremely rare cases in a paper published in 2021, it has not yet acknowledged the claims of a twist in court documents.

According to British media telegram, At first the lab denied the claims, but this February it was accepted in a legal document The drug, presented in the High Court as a product of collaboration between the company and the University of Oxford, “In very rare cases, TTS may occur”, i.e. thrombosis syndrome with thrombocytopenia, This causes people to have blood clots and low blood platelet counts. The same medium maintained this endorsement by the pharmaceutical company The plaintiffs could be awarded up to $125 million in damages.

The case was opened based on a complaint by a victim named Jamie ScottAfter being vaccinated in April 2021, he suffered an irreversible brain injury after suffering a head hemorrhage and hemorrhaging. It also means moral damage as the hospital announces that he will die.

According to British media, AstraZeneca sent a letter to Scott's lawyers in May last year: “We generally do not accept that TTS is caused by the vaccine.” But in a legal document submitted to the High Court in February, the lab said: “It is accepted that the AZ vaccine, in very rare cases, can cause TTS. The causal mechanism is unknown.” He further highlighted: “Furthermore, TTS can occur in the absence of AZ vaccine (or any vaccine). Causation in any individual case is a matter of expert evidence.

Daniela HosporThe situation was explained to Página/12, a professor at the Exactas Faculty of UNLP, principal researcher of Conizet and expert in vaccines. “First of all, it is worth remembering – said Hosphor – that the vaccine, in order to be used in the population, must fulfill a series of requirements that demonstrate its safety and effectiveness.”. This is done first in preclinical studies in animals and then in clinical studies in humans, where it goes through three successive phases.

In that regard, he elaborated: “First, research is done with small numbers of people, where the first assessment is whether the vaccine is safe. If this is the case, we move to clinical phase two, where the number of volunteers is increased to hundreds of individuals to get diversity, safety is re-evaluated and immunogenicity begins to be evaluated. If everything is successful, we go to the last clinical phase, where the number of tens of thousands of volunteers is increased and they should be of multicenter origin to increase the diversity, where the safety is re-evaluated and the function of the device is studied about the vaccine, that is, its effectiveness in terms of prevention. Only if all these phases are successful will the vaccine go to the population and continue to be studied there, “because at that time millions of doses are used, so there is still a lot of variation,” the expert clarified.

Referring to the controversy surrounding AstraZeneca's Covid-19 vaccine, Hosphor cautioned that these are “rare” cases, meaning they are of low frequency. “In the case of this coagulation syndrome with thrombocytopenia, some works have been reported that analyzed it, and it occurs between 0.2 and 0.3 per 100 thousand vaccinations, 1 per 100 thousand vaccinations. “This, based on the same blood clotting that causes the disease of Covid-19, is low” He explained.

The information found in clinical trials needs to be solid so it can be passed on to people, but once it starts to be used, research continues because something that wasn't seen in clinical trials might turn up. If so, it is stopped quickly and observed to see if this adverse reaction is related to the vaccine or not. Hosphor explained that this is what happened in the case of this vaccine: “During the pandemic, when AstraZeneca was used, there were adverse reactions and it caused these blood clots, which is why some countries stopped the vaccine and investigated the connection. In this way it was shown to be related, but with low frequency, to It is less likely to cause disease, which is why it has continued to be used. Only a few countries that had the option to use other vaccines decided not to use them in the second dose.

The expert explained that negative reactions are as low as possible, but “the risk-benefit is always compared.” “Obviously it was a very serious reaction to the person who touched him, but “What has been seen and continues to be seen is that the benefit outweighs the risk, so there is no need not to use it,” he clarified..

Hosphorus has promised that the vaccines are a “before and after” for the Covid pandemic, saving 14 to 20 million people in the first year of their application. In that sense, “its benefit is beyond doubt,” he said.

“The company declares that it is very good. Organizations need to get involved, research, analyze and help understand –he explained–. Knowledge of adverse reactions will help to develop new generations of vaccines and find better technology to further reduce risks.

“If you look at the history of vaccines, it's incredible what they've done and what they continue to do. It's estimated that vaccines used worldwide in immunization programs save about 154 million lives a year, which means six deaths a minute,” the expert said. “Researching, finding, and making sure that vaccines offer more benefits than risks is key to continuing to innovate and give seriousness to the work.”

Report: Lucia Bernstein Alfonsin.