A new study analyzing the immune response to COVID-19 in a Catalan cohort of health workers sheds light on an important question: does it matter whether a person was first infected or first vaccinated?

According to the results, the order of the events does alter the outcome, at least when it comes to long-term protection against omicron.

The study, published in Nature Communications, was led by the Barcelona Institute for Global Health (ISGlobal) in collaboration with the Catalan Health Institute (ICS) and the Jordi Gol Institute (IDIAP JG), and with support from the Daniel Bravo Andreu Private Foundation (FPDBA).