How we all hollered with outrage in May when Emmanuel Macron closed France’s borders to people arriving from Britain on the dubious basis that Britons, and Britons alone, were in danger of infecting France with the Indian variant. I believed, and I still believe, that Macron and his government were in part motivated by Brexit — it was part of our ongoing punishment for daring to vote to leave the EU. It certainly wasn’t justified on scientific grounds: if Briton had more recorded Indian variant (or Delta) cases than other European countries at the time it was largely thanks to more samples of Covid being sequenced here. Some countries, France included, were not analysing more than a tiny fraction of cases.

But the unfortunate truth is that our own government is every bit as petty — perhaps even more so. First, it kept European countries on an ‘amber list’ even when they had dramatically lower infection levels than Britain. For several weeks Britain allowed its own citizens, vaccinated under the NHS programme, to return from amber list countries without having to isolate — while EU citizens who had received the very same vaccines were still obliged to isolate for ten days. Pointedly, France was singled out to be an ‘amber plus’ country — meaning that all travellers from there were still obliged to isolate.

Now this has been lifted and double-vaccinated EU citizens travelling from amber countries are allowed to travel to Britain without having to self-isolate. Or some of them are, at least. Quietly last week the government changed the rules once again so that if you are double-vaccinated and are travelling from an amber list country you are still required to self-isolate if your two doses were of different vaccines. This will affect large numbers of Europeans who were given a first shot of AstraZeneca followed — after the emergence of problems with blood clots — by a second shot of Pfizer.

What is the scientific justification for this measure? There is none that I can find. On the contrary, the UK government has itself sponsored research at Oxford University on mixed doses. When interim results were published at the end of June they suggested that mixed doses of AstraZeneca and Pfizer could actually be better at provoking an immune response than are two doses of the same vaccine. The most effective combination seemed to be AstraZeneca followed by Pfizer.

I have an interest to declare in that AZ-Pfizer is the combination I have been given. Just like many Europeans, I asked for a different second dose after the blood clot problems emerged (71 people have died so far as a result of the AstraZeneca vaccine, according to the Medicines and Healthcare Products Regulatory Agency) and I troubled my GP and local vaccination centre to let me have Pfizer instead. Now, it seems the government has found a way to punish me — along with EU citizens who felt the same way — for daring to reject the great UK-developed and manufactured vaccine.

Sorry, but it is the kind of petty-mindedness I expected of Emmanuel Macron but not of our own, supposedly outward-looking, welcoming government. Far from establishing Britain as standing above nationalistic squabbling over vaccines, the government seems determined to engage in a tit-for-tat battle with EU member states. Citizens on either side of the Channel will be the losers.