Angela Merkel was given the Moderna vaccine two months after taking AstraZeneca as her first dose as Germany changes course with its cross-dose strategy.

The veteran chancellor’s spokesman announced on Tuesday that she received her second shot over the last few days.

Ms Merkel was given a dose of AstraZeneca in mid-April, some two weeks after Germany’s vaccine commission recommended that it only be given to people aged 60 and over.

The country’s vaccine commission at that time recommended cross vaccinating those under 60 who had already had a first jab with AstraZeneca as the second dose.

How the Covid-19 vaccines compare

But with deliveries of AstraZeneca and Johnson & Johnson way behind target, Germany may have to rely on combining vector and mRNA vaccines – such as Moderna and Pfizer – in order to fulfil its pledge of offering every adult a vaccine by the end of the summer.

The 66-year-old chancellor’s decision to have an mRNA shot as her second dose will be taken as a signal by Germans of all ages that this is a reliable way of building immunity against the virus.

Studies have shown that people who are cross-vaccinated with one shot of AstraZeneca and one shot of an mRNA vaccine have a slightly improved immune response over those who have received a double shot of the vector-based vaccine.

Germany has had to cope with massive delivery disruptions of the single-shot Johnson & Johnson vaccine due to suspected contamination in a US factory that led to 60 million doses being destroyed.

Berlin had purchased 10 million shots from the US company for the end of June, but it now only expects to receive 3.4 million by then.

Sebastian Dullien, an economist at the Institute for Macroeconomy in Berlin, estimates that Berlin will only hit its targets if it uses its abundant supplies of the Pfizer jab to give second doses to those who’ve had AstraZeneca.

Germany’s rollout got off to a slow start at the beginning of the year, but gained rapidly in momentum through April and June. Over half of the population has now been vaccinated at least once.