Prevent is often followed either by a possessive adjective + gerund or by an object + from + gerund. Prevent can also be followed by the gerund directly when the subject is unnecessary, and it can be followed by a noun.
- You can't prevent my leaving.
- You can't prevent me from leaving.
- I want to prevent his getting sick.
- I want to prevent him from getting sick.
- This campaign is designed to prevent drowning.
- Preventing stealing is our main goal this year.
- We are working to prevent forest fires.
- This vaccine will prevent malaria.