Anxiety about AstraZeneca’s COVID-19 vaccine is understandable.

It started off on the wrong foot with confusion over half-dosing. Then there were clashes within the European Union, a war of words, and the decision to block exports.

Now, the issue of cases of thrombosis (blood clots) has arisen as by all appearances it is linked to this vaccine for reasons that are still unclear.

Hence, we see an unease, apprehension, and a wait-and-see attitude in the population, as Ta Nea reported yesterday, which will likely continue until the European Medicines Agency delivers an opinion on whether the AstraZeneca vaccine should not be administered to certain categories of the population, such as young women.

Whatever the case may be, there are three things that one should remember.

Firstly, the number of thrombosis cases linked to the AstraZeneca vaccine is extremely small. As epidemiology professor Sotiris Tsiodras said yesterday at an even organised by the Academy of Athens, at most one in 100,000 people (0.001 percent) to whom the vaccine has been administered will be afflicted with thrombosis, whereas the percentage among people with serious cases of COVID-19 is 69 percent.

Secondly, COVID-19 can have a very bad outcome in a person who is otherwise in perfect health, and approved vaccines are over 70 percent effective.

Thirdly, mass vaccination is the only way to get beyond this painful adventure. A gradual return to normalcy will require vaccination of 60-70 percent of the population and that requires use of all approved vaccines that are available.

That does not mean that we should not know the highly unlikely side effects of a vaccine and the ways to ensure protection against them.

Transparency was always the ally of science.