It is something that specialists have repeated ad nauseam: the risk of suffering a thrombosis after vaccination against Covid-19 with Vaxzevria, the AstraZeneca serum, is very small and the benefits far outweigh its dangers in all age ranges. Three months after the European Medicines Agency (EMA) ruled in favor of continuing vaccination with AstraZeneca, the data have not qualified this statement one iota.
The sixth report on pharmacovigilance of vaccines against Covid-19 of the Spanish Agency for Medicines and Health Products (Aemps) indicates that, as of May 30, 21 cases of thrombosis syndrome with thrombocytopenia had been registered in our country (low platelet levels) in people who had received the first dose of the vaccine. It is estimated that there are 4 cases per million injections.
The reported rate of this syndrome for each age group ranges from two cases per million doses in people between 50 and 69 years to 14 cases in those between 30 and 39. Among the twentysomethings it is 4 cases per million , and in people aged 40 to 49 years of 12 cases, the second group with the highest rate.
In their 30s, men have a higher rate, but it is still very small: 22 cases of thrombosis syndrome with thrombocytopenia per million inoculated doses. We are only talking about cases suffered: there have only been five deaths in the total population vaccinated with AstraZeneca.
To make it even clearer, the EMA compared the number of cases averted, missed hospitalizations and lives saved by Vaxzevria versus the cases of thrombi caused by it, in three estimates for low, medium and high infection levels in Europe.
Taking as reference a 14-day cumulative incidence of 500 cases per 100,000 inhabitants, the one registered by the Ministry of Health this Thursday, July 15, the number of hospitalizations avoided per 100,000 people after the first dose is 37, 54 and 81 in the 20, 30 and 40 age groups. The number of cases of thrombosis syndrome with thrombocytopenia produced by Vaxzevria would be around two for each group. 3, 5 and 10 admissions to the ICU would also be avoided.
The only indicator that can generate certain doubts is that of the deaths averted with the vaccine. In the age group between 20 and 29 years, no deaths would be prevented per 100,000 inhabitants, and it is the fact that the number of deaths from Covid in this group is very low. That is why the UK decided to offer an alternative to AstraZeneca to those in that age group who had already received the first dose.
In the rest of the groups, the accounts continue to appear: 2 deaths avoided among those in their thirties, and 7 among those between 40 and 49 years old. From the age of 50, the differences are much clearer.
National vaccination strategy
Despite the clarity of the data, the national vaccination strategy against Covid-19 established, on April 20, that only people between 60 and 69 years old would be vaccinated with AstraZeneca. In cases where a person under that age had already received their first dose, it was decided to wait for the first results of the CombiVacs study, which examined the generation of immune responses with a heterologous or mixed regimen. That is, by administering a second dose of the Pfizer vaccine instead of completing the regimen with the AstraZeneca one.
Following the publication of the results of this study, this second dose of Pfizer was chosen for those under 60 years of age, something that also it has been made in other countries such as Germany, Italy or Portugal. However, the person who wanted to be booster vaccinated with Vaxzevria would sign an informed consent and it would be administered.
Faced with a possible lack of vaccine supply to attend all open appointments for vaccination this summer, doctors see no problem in using the leftover doses of AstraZeneca in other age groups under the age of 60.. “I would be in favor of putting it,” says Isabel Jimeno, head of vaccines for the Spanish Society of General and Family Physicians (SEMG). “But I wouldn’t do it in those under 30”, he clarifies, recalling the case of the United Kingdom and the calculations used by the EMA.
Jimeno indicates that the ideal would be to vaccinate with this serum to the age ranges of 40 and 50 years “and also vaccinate those who have had the disease and are over 30 years old, since a single dose is enough for them “.
From the Spanish Society of Epidemiology they lean towards “Follow the technical data sheet for each of the vaccines”, explains its vice president, Óscar Zurriaga. “At the time, the debate was raised”, that is, when there was a stop in vaccination with AstraZeneca, in March, after the first cases of thrombosis, “and we always went to what the technical data sheet said”.
The Vaxzevria technical sheet, updated on July 7, establishes that it is indicated “for active immunization to prevent Covid-19 caused by SARS-CoV-2, in people 18 years of age and older“. It is also indicated, in the section on warnings and special precautions for use, that the cases of thrombosis syndrome with thrombocytopenia occurred, for the most part, within the first three weeks after vaccination and occurred mainly in women under the age of 60 years, although it does not establish contraindications in this regard beyond for people who suffered the syndrome with the first dose.
Donate leftover vaccines
“The benefits far outweigh the risks,” he explains. Marcos López Hoyos, president of the Spanish Society of Immunology. “You have to vaccinate: the vaccine is time gained from the virus.” Of course, he warns that the first of all is planning to carry out the vaccination with an order.
For this reason, it is inclined because it is from the Ministry of Health that the necessary steps are taken so that, in case the vaccines are needed, those of AstraZeneca can be used “in their complete schedule”. At least, in those over 30 years of age, “what minors have to do is take preventive measures”.
For López Hoyos, it would not be anomalous to vaccinate other age groups other than the one established in the strategy with AstraZeneca, since the technical data sheet allows it. Furthermore, “no incidences of thrombosis with thrombocytopenia have been heard at this time.”
Who is more cautious is Fran Álvarez García, coordinator of the vaccine advisory committee of the Spanish Association of Pediatrics. Although he admits that it has been the Ministry who has made the recommendation of the age group “without it being in his technical file”, he is inclined not to extend the vaccination to other groups but to donate the remaining doses to the Covax initiative, the strategy set up by the World Health Organization to bring vaccines to low-income countries.
“The European Union has bought five doses for each citizen, it is logical that surpluses go to low-income countries“So before vaccinating with AstraZeneca, he prefers to wait for the massive shipments of Pfizer vaccines in August to recover.
Follow the topics that interest you
The Canadian News
Canada’s largets news curation site with over 20+ agency partners