The AstraZeneca laboratory admitted before the British Court that its vaccine against Covid 19 could have “a rare side effect.” The recognition occurred in the midst of a class action lawsuit that was initiated in that country against the pharmaceutical company, due to the adverse effects produced in a limited number of cases by the applications that occurred during the 2020 pandemic.
Although the Pharma company had already pointed out in a paper published in 2021 the possibility of this adverse effect in very rare cases, it currently does not recognize the claims that there has been a twist in the court documents.
According to the British media The Telegraph, at first the laboratory rejected the claims, but this February it ended up accepting in a legal document that it presented to the High Court that the drug, a product of collaboration between the company and the University of Oxford, “can, in very rare cases, cause TTS,” that is, thrombosis syndrome with thrombocytopenia, which causes people to have blood clots and a low blood platelet count. The same medium maintained that this recognition by the pharmaceutical company could lead to compensation of up to $125 million for the plaintiffs.
The case was opened based on the complaint of an affected patient named Jamie Scott, who suffered an irreversible brain injury after developing a blood clot and hemorrhage in his head after being vaccinated in April 2021. The cause also involves a moral damage, since the hospital notified his wife and two children that he would die.
According to the British media, in May of last year AstraZeneca sent a letter to Scott’s lawyers saying: “We do not accept that TTS is caused by the vaccine at a generic level.” But in the legal document submitted to the High Court in February the laboratory said: “It is accepted that the AZ vaccine can, in very rare cases, cause TTS. The causal mechanism is unknown.” He also highlighted: “In addition, TTS can also occur in the absence of the AZ vaccine (or any vaccine). Causation in any individual case will be a matter of expert evidence.”
Daniela Hozbor, professor at the UNLP Faculty of Exactas, principal researcher at Conicet and vaccine expert explained the situation to Página/12. “It is worth remembering first – said Hozbor – that the vaccine, in order to be used in the population, has to pass 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 phases sequentially.”
In that sense, he detailed: “In the first, research is carried out with a small number of individuals, where the first thing that is evaluated is whether the vaccine is safe. If this is the case, we move on to clinical phase two, where the number of volunteers is increased to hundreds of people to have diversity, safety is re-evaluated and immunogenicity begins to be evaluated. If everything is successful, we move on to the last clinical phase, where the number is increased to tens of thousands of volunteers and they are sought to be of multicenter origin to increase diversity, there the safety is evaluated again and the functionality of the device is studied. the vaccine, that is, its effectiveness in terms of prevention.” Only if all these phases are successful does the vaccine go to the population and it continues to be studied there, “because at that moment millions of doses are applied, so there is even more diversity,” the expert clarified.
In reference to the controversy surrounding the AstraZeneca Covid 19 vaccine, Hozbor warned that these are “rare” cases, that is, of low frequency. “In the case of this thrombosis syndrome with thrombocytopenia, some works have been reported where it was analyzed and it was observed that it occurs between 0.2 and 0.3 per 100 thousand vaccinations, up to 1 per 100 thousand vaccinations. This, in terms of the same thrombosis that causes the Covid-19 disease itself, is low,” she explained.
The information found in clinical trials must be robust, that is why it can be passed on to the population, but once it begins to be applied, the research continues because something may appear that has not been seen in the clinical trials. In that case, it is stopped quickly and it is observed whether or not this unexpected adverse reaction is associated with the vaccination. Hozbor explained that this is what happened in the case of this vaccine: “During the pandemic, when AstraZeneca was applied, adverse reactions were seen and it was observed that it caused this thrombosis, which is why some countries stopped vaccination and investigated its associativity. In this way it was shown that it was associated, but with a low frequency, this being lower than that caused by the disease itself, which is why it continued to be applied. Only some countries that had the option of using other vaccines decided not to use them in the second doses.”
The expert explained that what is sought is that adverse reactions are as minimal as possible, but that “the risk-benefit is always compared.” “Obviously, for the person who touched it, it is a very serious reaction, but what she saw and continues to see is that the benefit is greater than the risk, so it is not necessary to take it out of use,” she clarified.
Hozbor assured that vaccines are “a before and after” in the covid pandemic, saving between 14 and 20 million people in their first year of application. In that sense, “its benefit is not in doubt,” he stated.
“For the company to declare this is very good. It is essential that companies get involved, that they do the studies, that they investigate and that they help with understanding – he explained -. Knowledge of adverse reactions can help improve new generations of vaccines and find more and better technology to further reduce risks.”
“If we look at the history of vaccines, it is incredible what they have done and what they continue to do. There are estimates that show that the vaccines used throughout the world in immunization plans save about 154 million lives per year, that is, they prevent six deaths per minute,” said the expert and completed: “Research, search and Ensuring that vaccines provide more benefits than risks is key to continuing to innovate and giving seriousness to the work.”
Report: Lucía Bernstein Alfonsín.
