spike in antibodies. cnn's senior medical correspondent elizabeth cohen has been looking at the data here.ause it shows that not only one vaccine, if you get that booster, you can really boost your immunity to this. >> that's right. let's go over a little bit what the johnson & johnson vaccine is. it's been a while since we've spoken about it. so, johnson & johnson has been called the one-shot wonder. you only need one shot. but remember, in their clinical trials it was 66% effective against moderate and severe covid. good, but not as good as the other two vaccines that at that time were more around 95%. so let's take a look at what the study did. it was a small study. what they did was give everyone one shot. waited six months later, and antibodies increased nine fold. in other words, from the one shot, about 28 days later, antibodies reached a certain level. but when they waited 28 days after the second shot, antibodies increased nine times where they were shortly after that first shot. that really is saying something. now, jim, i'll adhere that one-shot wonder, several public health exp