There are many Filipino scientists. I've listed some with their respective contributions and branches.
Benjamin Cabrera, M.D., M.P.H. (Medical Parasitology)
-> He deals with incidence, distribution, and control of disease in a population, and life cycles. He published medical parasitology and public health papers.
Magdalena C. Cantoria, Ph.D (Botany)
-> She researched about morphology, physiology, and biochemistry of drug plants, pharmacognosy, and many more.
Felix D. Maramba, Sr. (Physics)
-> created a coconut oil-fueled power generator and developed a biogas system