Three days after the suspension of the administration of the AstraZeneca vaccine in the under 60 in Germany for possible side effects, related to rare thrombotic events, too Holland temporarily suspends the vaccination of people under the age of 60.
The undesirable effect – it must be repeated, extremely rare – occurred 7-10 days after vaccination in women between the ages of 25 and 65: these data have prompted the Dutch Ministry of Health to move in this direction, as a precaution.
The British data
At the same time, the UK medicines control authority (Mhra, The Medicines and Healthcare products Regulatory Agency) released updated data on thrombosis cases that could be linked to the AstraZeneca vaccine in a new drug surveillance report. (Also in this case, it should be remembered that at the moment there are no established causal links between vaccination and thrombotic events, which are currently under investigation).
They have been reported 30 cases of adverse events concerning the blood clotting its over 18 million administrations of the drug.
In the previous monitoring, (the one on which the evaluations of the European Medicines Agency called for an evaluation on the issue after the suspensions of various European governments, including Italy, were based), the British body had detected only five cases out of 11 million administrations.
With these new numbers the rate of accidents related to clots therefore rises to 1 in 600 thousand, British experts point out. In detail, 22 reports concern cases of cerebral venous thrombosis (CVST, thrombosis of the sinus vein) and 8 events of thrombosis in combination with a low number of platelets (thrombocytopenia). Almost all cases concern people under 60 even if the report made public does not specify the age group.
The UK agency also reported of have not received any such reports after Pfizer-BioNTech vaccine, the other used in the UK.
However, the MHRA concluded that the benefits of the vaccine continue to outweigh the risks.
E also the EMA reiterated that to date there is no evidence to suggest the exclusion of some age groups from drug administration although investigations into reported cases of rare thrombosis are continuing.
The choice of Germany
Doubts about adverse effects related to having thrombotics, in particular on people of young age (almost always women) have triggered precautionary measures, in particular in Germany where a few days ago the standing commission for the German vaccine (Stiko) recommended the use of the AstraZeneca vaccine only for citizens over 60 years old.
The decision of the German government derives from the fact that in Germany 31 cases of thrombosis have been reported, almost all in the brain out of 2.7 million vaccinated, almost all under 60. These are rare adverse events that generally have a lower frequency in the general population.
The same commission yesterday suggested with a document still in draft of give the second dose with an mRNA vaccine to people under 60 who have already received the first dose of AstraZeneca. The decision could affect 2.2 million Germans, of whom only two thousand have received the second dose).
Other countries have chosen age restrictions: in Sweden it can be given to those over 65, in France over 55 years old.
Risk-benefit calculation by age group
What emerges is that people who develop the thrombotic problem that would be associated with the AstraZeneca vaccine are of such age that they probably would not die if they fell ill with Covid-19 while half of the thrombotic events linked to a fatal low platelet level reflect the immunologist Sergio Abrignani, Professor of General Pathology at the University of Milan.
While the benefit of the vaccine is enormously greater than the risk of thrombosis in over 55s, in the younger population the data deserves further reflection on the risk-benefit ratio. Since we have different vaccines available, under the age of 60, pending further investigations, it may be appropriate to evaluate the possibility of proceeding with mRNA vaccines.
The German hypothesis of the vaccine mix is not rejected a priori but phase 3 trials are needed that do not yet exist. According to Sergio Abrignani, one thing that makes sense, because it can work immunologically. I am sure that using one of the other two RNA vaccines approved in Europe for the second dose after the first dose with AstraZeneca will work because it induces a strong immune response.
April 2, 2021 (change April 2, 2021 | 21:18)