Memorial gears up for COVID vaccines

Good news for sure. I'm a little perplexed at a few things though. Full disclosure, I know nothing about this other than what I'm reading in the article. First, the slightly more effective Moderna vaccine which the article states is to be made in Portsmouth, isn't what Memorial will be gearing up to get. That vaccine it also states, is less difficult to store. It indicates Memorial does have the ability to store the Moderna vaccine. The Pfizer vaccine needs special freezers and the article states that most hospitals don't have the freezers. It says Memorial does have the ability to store Moderna, which to me, means it doesn’t currently have the ability to store the Pfizer vaccine. But then goes on to say that it was 'gearing up' to get the Pfizer vaccine. So to me, this means that a locally manufactured vaccine that Memorial can already store, isn't what it's going to get? I understand that they most likely have no control over what they are going to get, but that’s a little bit of a downer. Still good news, but… It will have to get all the special freezers for the Pfizer one? Maybe that is what 'gearing up' means? Also, I am not a doctor or expert of any kind on this subject matter so I'm trying to figure out how "15,000" people were part of the study, and '5' people got Covid. Yet it said it's '94.5%' effective. I am guessing that the effectiveness is not actually the % of the 15,000 that got Covid because that would be way under 1%. It's more like 0.03%. So obviously I'm not understanding how they got the 94.5%. I'm sure it's right...I'm just not liking how it just kind of blindly eludes that 5 of 15,000 got Covid then mentions that %. There's more to it I'd like to understand, with regards to how they got those numbers. Any dr.s or research folks out there that can chime in w/ some additional info on how they get the effectiveness? Just wanting to better understand. Either way, it's exciting. There's just a bunch of details still I'm not sure about after reading this.