risk of hospitalization. cnn's senior medical correspondent elizabeth cohen joins us. walk us through the findings and what this means in the fight against covid. >> so, aprila this, study is from a very large insurance company in south africa. it's with more than 200,000 mashts, but what's good is it very much resonates, it's very much the same thing that was found by pfizer and that was found by another lab in south africa as well as a lab in the uk, so let's get right to the findings for this group in south africa. what they found is that folks who got two dose of the pfizer vaccine, they were only 33% protected against infection. that's not great. that's a very low number. only 33% protected against infection, but they found that pfizer was -- two dozes of pfizer was 70% effective against hospitalization, so that is the good news there. now, when pete -- when we hear, and this will happen in the u.s. because omicron is here and it's