but it also finds a fourth dose may not provide enough of those antibodies to protect against the omicron variant. let s bring in cnn senior medical continue eliza correspondent elizabeth cohen. in israel, several weeks ago they started giving fourth doses to people who were immune compromised, to people who were 60 years of age or older, and also to health care workers. so they decided to see, when we give it to health care workers, what happens, let s take a look at what shiba did, they gave fourth doses to 274 health care workers, some got pfizer, some got moderna. the fourth dose did raise antibodies, they weren t sure. they didn t give any data as to whether or not getting that fourth dose did what we want it to do is prevent severe disease,
authorized booster shots for tens of millions of recipients who got moderna and johnson & johnson vaccines, something cdc advisers will also vote on this afternoon. more authorizations which also mean more questions. joining me right now is cnn s chief medical correspondent, dr. sanjay gupta, for more on this. good morning. sanjay, can you explain this all to us, who qualifies and who can get which vaccine at this point? yeah, sure. so this is going to sound familiar because this is basically the same pattern that pfizer followed with their authorization of the boosters and then the cdc recommendation. so if we look at moderna, for example, what they re going to say is who are the people most likely to develop a significant breakthrough infection, one that leads to severe illness? those are the people that may most benefit from a booster. people over the age of 65. any adult who has some sort of risk factor, which is a lot.
johnson vaccine a two-dose regimen now? i think you possibly could think of it that way. it s interesting, even if you go back and look at the original pfizer and moderna, what you hear from people like peter hotez, is there s always likely to be some boost at an interval. the first two shots together were just together to prime the immune system. you needed two together to prime the immune system. so the idea that you would need a boost later on was not that surprising to people who work on these vaccines. for johnson & johnson you re right, you could consider this a second shot. there s a difference in the terminology which most people don t use, but the boost is something to boost the immune system, whereas another shot like a third shot could be in people who did not respond to the vaccine well in the first place. like someone who has a weakened immune system, for example. but yes, two months at least for the johnson & johnson interval. there s one thing that i m curious about
moderna and pfizer and their kind of vaccine regimen here. you know, the guidance is the booster can come at least six months later. six months. if the maudeoderna booster i half the dose of the initial shot, is that significant? i think that s really interesting that you picked up on that and i think it is significant, but maybe for the exact opposite reason people think. i think what they do in these situations, they basically try and figure out what is the lowest dose we can use to get a significant antibody response. even with pfizer early on, you may remember they had some high doses they used that were causing some significant side effects and they just gradually settled in on the dose that they used for the pfizer vaccine, which is 30 micrograms. for moderna it was 100 micrograms so a higher dose, much higher. now they re saying 50 micrograms is enough for the boost. it s based on the data that they re collecting trying to
94%, 95% protected against getting sick from covid-19 but soon after the johnson & johnson vaccine it was 72%. 72% is still a god vaccine, but it s not as good as moderna and pfizer s, so i think there s more of a feeling of urgency that a second shot is especially important for those who got johnson & johnson. now, ana, you mentioned mixing and matching. these vaccine experts will hear about a study where some people got pfizer and then as a booster got moderna and then as a booster got johnson & johnson and all of the possible combinations. what they found was that it worked and that it was safe and that actually folks who got johnson & johnson, they were actually better off getting a booster from pfizer or moderna rather than getting another johnson & johnson shot of the right now this is a relatively small study. just under discussion. there will be no recommendations today about mixing and matching. ana? elizabeth cohen, thank you. we ll eel stay on top of that