This is an administrative change: a change in the coding of vaccination certificates with Johnson & Johnson's single-dose vaccine, named Janssen.

"Luxembourg has aligned itself with a recent European recommendation which recommends encoding a first dose of Janssen vaccine as 1/1 (first dose on an initial single-dose schedule), and then, if necessary, the booster vaccination with a second Janssen dose or an mRNA vaccine (a so-called mix&match schedule) with the code 2/1. It is important to understand that the certificate coded 2/1 is read in exactly the same way as the old 3/3 certificate by the CovidCheck application in Luxembourg and that the 2/1 dose is therefore currently considered as a booster dose.

This change has "led to a number of people being issued with new, corrected certificates,” the ministry said.

The rule is the same for travel within the European Union, which recognises the European digital Covid certificate. But some countries may have fallen behind in updating the encoding rules, which is why Luxembourg recommends keeping its old 3/3 certificate, which "remains valid".

Not to be confused with the new German rule

No big change then: two doses are still sufficient in Luxembourg and in most of the country with the Johnson & Johnson vaccine.

At least for the time being. Germany, on the other hand, has decided since 15 January to require a three-injection vaccination schedule for people who have received their dose of Janssen. The country "considers that the protection provided by a vaccination schedule based on an initial injection of Janssen vaccine, followed by a simple booster, is not equivalent to the protection provided by other three-injection booster vaccination schedules. Others may follow. "Other European countries, as well as Luxembourg through its Higher Council for Infectious Diseases, are conducting similar reflections," writes the Ministry of Health.

This story was first published in French on . It has been translated and edited for Delano.