For a 15-month-old child, deworming with albendazole is commonly recommended, and the usual dose is 200 mg as a single dose (this equals 5 ml if using a 200 mg/5 ml suspension), which may be repeated after 2 weeks if advised by a doctor, depending on the type of worm infection. It is generally given after food to reduce stomach upset. However, since your child is under 2 years of age, it is best to give this medicine only after consulting a paediatrician to confirm the need and exact dose, as safety and dosing may vary slightly based on the child's weight and condition. Also, maintain good hygiene practices like regular handwashing, keeping nails short, and washing fruits and vegetables properly to prevent reinfection.