ModeRna have announced that their vaccine is 95% effective. the trial used 30,000 people. Half had a dummy (placebo) injection and half had two doses of vaccine, four weeks apart.
95 of these developed Covid-19 symptoms. Of those, 5 had been vaccinated, 90 had not. 90/95 works out at 95%, There were 11 cases of severe Covid - none of them were in the vaccinated people.
The ModeRna vaccine is not one of the ones that the UK government pre-ordered, so if that vaccine is used in the UK, that won't be until well into 2021.
One of the good characteristics of this vaccine, is that it can be stored in an ordinary freezer (at -20C) - it doesn't need the -75C that the Pfizer vaccine needs.
For both the Pfizer and the ModeRna vaccine, we don't know if it also stops people from spreading the virus. This is because you can become infected. Your immune system immediately starts fighting the virus, having been given the heads-up by the vaccine. But while this is happening, can you spread the virus? We don't know yet, but it's thought that maybe half of those infected on't be spreaders.
Side effects? Yes, but slight. When I had my recent flu jab, my left upper arm felt like it had been bruised, but this stopped after a couple of days.
Is 95% better than the 90% of the Pfizer vaccine? I dn't think there's much in it. At this level of protection, and with the relatively small number of people that were vaccinated and got Covid (five), you can see that those five might have been a few more. I'd say that it's not statistically different.
In America, Trump is refusing to allow health officials to talk to the incoming Biden administration. If this continues, then on January 20th, there will be a hiatus in the vaccine distribution system.