I got my first Moderna vaccine a couple of days ago. A little tenderness in the shoulder, not enough to even say ache and only if I raise my arm above horizontal. Looking forward to the next shot. Until then, I'm still doing the 'safer at home' routine.
I went in to my doctor for something unrelated to Covid. I asked her about the vaccine and she already had her first dose.
Y'know that there's a version of the vaccine that needs extreme cold and one that need just pretty cold? My doctor said that there's also one that can handle more normal-ish temps (I think it's from Pfizer). This is the one that they're going to try to help 3rd world countries with and/or just really hard to get to places. It's supposed to be in the mid-70% effective.
I was listening to the news on the radio, on the same day I went to the dr. Seems you have to be almost exactly on time for your scheduled second shot or you can have problems. One of the interviewed folks said that only the one dose is about 50% effective in stopping Covid. So, the conclusion was, unless we do the second shot on time, we're not going to be building enough herd immunity to cover folks that can't take the vaccine, for whatever reason. Kinda like how I'm allergic to the flu vaccine: I count on other people around me getting the shot so I don't get sick.
FWIW, even after I get the two shots, you're not going to see me in public without a mask.
The Pfizer version is the one that has to be stored at -70 to -80 deg C. They are shipped in batches of 975 doses (195 vials of 5 doses each) which once opened, must all be used within 3 and half days. Once reconstituted, each vial must be used within 6 hours. Although each vial is said to have 5 doses, you can actually get 6 doses from them if care is taken drawing up into syringes. They are 90% effective within 12 days of the first shot, and becomes 95% effective son after the second shot if the booster is done 21 days later. There is no evidence to say the second booster can be delayed beyond a 3 week gap, but UK are assuming it can, with no reduction in efficacy.
The Astra Zenica (Oxford) vaccine is the one that can be stored at 2-8 deg, normal fridge temp. This is the one likely to be used around the world in places where it is important to not have any specialist refrigeration. It is 70% effective 2-3 weeks after the first dose, and although intention is to boost at 4 weeks, they actually have evidence that it is more effective if that is delayed, but not beyond 12 weeks after the first vaccination.
The USA vaccine (Moderna) I believe must be stored at -20 deg, but UK will not be taking delivery of that for a couple of months yet, so I can't give any more detail.
UK are delaying all second doses until 11 to 12 weeks in a bid to get as many first doses out there as possible, starting with elderly and health care workers.
I hope an effective vaccination programme is rolled out as quickly as possible wherever you are, and that as many people take advantage of it as possible.