My daughter's boyfriend, an RN, has been fully vaccinated with the Pfizer vaccine. This week, on the advice of hospital management, he is getting the first of two jabs of the Moderna vaccine.

Anyone else heard of this double vaccination approach?

This seems strange, aren't the Moderna and Pfizer vaccines built using the exact same mRNA sequence?

They're not identical, though similar. You can see them here:

https://github.com/NAalytics/Assemblies-of-putative-SARS-CoV...