Have I correctly used 'persuaded,' 'the,' and 'help prevent' in these sentences?

Have I correctly used 'persuaded,' 'the,' and 'help prevent' in these sentences?

1. My friend, a nurse, has persuaded my schoolmates to take the necessary precautions against the spread/transmission of measles and influenza.
2. Dr. Morgan motivates young people to help prevent the spread/transmission of chickenpox.