The case of the rare and complex thrombosis with contextual platelet deficiency induced by viral vector vaccines such as Oxoford-Astrazeneca e Jannsen (Johnson & Johnson) seemed to have been somewhat closed with the decision of all European countries to set a minimum age threshold. But two cases involving two young women of 18 and 42 immunized during the Open days on a voluntary basis, organized in Liguria e Tuscany, have reopened the debate in Italy. Also because, as stated in the document drawn up by the commission of experts appointed by AIFA – and published on May 26th – the rare events induced by the vaccine – discovered by German researchers now three months ago – “they were seen almost exclusively within about three weeks from vaccination in healthy subjects under the age of 60, mainly women “. Reason why the Astrazeneca vaccine continues to be administered to over 60s in vaccination centers.
After the first cases reported last March, the decision of theEuropean Medicines Agency had been – in consideration of the risk / benefit ratio and in the presence of very few events – not to limit the use by age group. But soon after came the simultaneous decisions of the national regulatory bodies of several European countries to introduce a recommendation threshold for age or even to suspend the use of the compound. As it happened in Norway e Denmark. France and in Belgium which set the threshold at 55 years, Spain has instead decided to limit the use of the vaccine only to those who are born between 1952 and 1961, i.e. 60-69 year olds, Germany e Italy have recommended its use to people over 60.
In Great Britain – homeland of the compound with which the 56-year-old premier was also vaccinated Boris Johnson – first the administration threshold was set for the over 30s and then subsequently raised to 40. The Oxford researchers also suspended the experimentation of the vaccine they developed on the under 18. With millions of doses stopped in refrigerators in Italy as well as in other European countries, Germany in primis, the open day initiatives have been launched to give those who wish to vaccinate themselves with a compound considered “effective and safe“. So much so that both the Italian Prime Minister, Mario Draghi (73 years), and the German Chancellor Angela Merkel (66 years) have been vaccinated with Astrazeneca. And the initiatives on a voluntary basis have mostly met with good success.
In April, however, it was already known that the number of rare cases thrombosis associated with platelet deficiency ascertained after vaccination with Astrazeneca had been “higher than expected”Among people under the age of 60, while it had been“ inferior ”or in line with statistics for over 60. This is why Italy had decided to “recommend preferential use“Of the compound only for those over 60, an indication based on the principle of”maximum precaution“As the president of the Higher Health Council and CTS coordinator explained, Franco Locatelli, during the press conference that took place at the Ministry of Health on Wednesday evening, on the very day when the Ema had returned to express itself on the vaccine (without setting any stakes).
“Even the cases of Vaccine-induced Immune Thrombotic Thrombocytopenia (VITT) reported after the first dose – reads the Aifa document – involved a few subjects per million vaccinated, mainly female, and concentrated in the age group between 25 and 60 years”. In any case in Italy “as of April 26 they have been reported 34 cases of venous thrombosis in atypical locations, 18 of which associated with thrombocytopenia. Compared to the administrations carried out with Vaxzevria, therefore, 0.45 cases per 100,000 vaccinated are observed, given that – the experts write – it could be affected by less representativeness of the Italian sample compared to European and Anglo-Saxon data. As for the events observed after administration of the Janssen vaccine, the US surveillance system “Morbidity and mortality weekly report” 5 as of April 30, 2021, reports 17 cases of thrombosis in atypical locations associated with thrombocytopenia (events very similar to those observed with the Vaxzevria vaccine) on 7.98 million doses of this vaccine administered in North America ”.