Research on vaccines can help us find better treatments for diseases that spread quickly. However, there are still some big challenges we need to tackle:

1. Understanding Immune Response: It’s tough to figure out how vaccines help our bodies remember how to fight off diseases. Everyone reacts differently to vaccines, mainly because of our unique genes and backgrounds.

2. Vaccine Effectiveness: Some vaccines don't work well against germs that change quickly. This makes it tricky to create vaccines that last over time.

3. Public Doubt: Many people are unsure about vaccines. This doubt can make it harder for everyone to stay safe.

To tackle these issues, here are some ideas:

• Do more research on adjuvants, which are substances that help vaccines work better.
• Create vaccines that are customized for each person based on their genetic information.
• Work on better ways to explain vaccines to the public so they understand why they are important.