Pedro L. Alonso spends much of his time researching Malaria, Pediatrics, Plasmodium falciparum, Pregnancy and Incidence. His studies in Malaria integrate themes in fields like Randomized controlled trial and Vaccine efficacy. The various areas that Pedro L. Alonso examines in his Pediatrics study include Chemoprophylaxis, Surgery, Placebo and Epidemiology.

His Plasmodium falciparum research is multidisciplinary, incorporating perspectives in Internal medicine, Chloroquine, Public health and Virology. His study looks at the intersection of Pregnancy and topics like Obstetrics with Gestation, Gestational age and Birth weight. His study in Incidence is interdisciplinary in nature, drawing from both Disease burden, Adverse effect, Diarrhea and Bacteremia.