Funnily enough, my speech when I was in year 12 was about the 'No jab no play' laws and I'm also very passionate about the topic.
I'll be echoing some of Bri's excellent points but I'll also add to them.
Not many will disagree with the points you've made, but I don't quite understand what your contention is. In your second paragraph, your first sentence "Children should not be enrolled to schools if they are not vaccinated" screams a contention, yet you don't seem to come back to this point at all. In fact, you almost change your focus to where you try to essentially convey that 'vaccines are good'. Try to pick a clear contention and make sure your arguments
directly support your central idea. This will help with the clarity of your speech as well.
Next, audience! Who is your audience here? The way you write and the substance of your speech needs to target them specifically.
Your sentences are too complicated. I found some that are 4 lines long. Your use of hyphens and the word "although" particularlu bothers me. Chop up your sentences. Eloquence in speech doesn't come from long sentences. It comes both from easy to understand thoughts which people can understand. Read your speech aloud to someone. If they struggle to understand it or don't seem engaged, it's not their fault. It's your's.
You've made some great refutations and counterarguments. I think if you just made them simpler, they will read very well. However, you also have some low forms of argument - mainly, ad hominem. I've found that attacking someone's character is the worst way to convince them of your point of view and often will increase their affinity to their beliefs. It often takes great discipline not to do so, especially when frustrated with opposing views. Attack the substance of your opponents' argument, not their persona. As much as it is the case that many people think anti-vaxxers are unintelligent for their views, you have to realise that they have been convinced by someone else's words. I don't believe for a second that anti-vaxx parents don't have the best in mind for their children. Most are misinformed, not deliberately turning a blind eye.
I highly suggest you watch
Kurzgesagt's video on vaccines. Pay particular attention to their conclusion from 9:35.