Split and simplify the following sentence while retaining its full meaning: "Pappi-Vit" ( Nutri-vet ) - provides puppies with everything necessary up to 9 months of age , the main focus of the drug is to strengthen immunity .
 Simplified version:
"Pappi-Vit" ( Nutri-vet ) - provides puppies with everything they need up to the age of 9 months . The main purpose of the drug is to strengthen the immune system .