*2.5. Systematic Literature Review*

A search was performed on the PubMed database up to 2022. Search terms used were: "giardia" OR "giardiasis", AND "common variable immunodeficiency" (37 results). Articles available in English and Spanish were included, and articles that were not related to the subject of the study or did not provide sufficient data on treatment for giardiasis, microbiological and immunological diagnosis were excluded. Finally, 16 articles were included (Figure 2).

**Figure 2.** Flowchart of study selection for the narrative review.
