I get the need for the absolute risk reduction number but it would seem to me the only way to find that is to know how many who've been vaccinated have been exp

I get the need for the absolute risk reduction number but it would seem to me the only way to find that is to know how many who've been vaccinated have been exposed to the virus afterwards, or to purposely expose them. It would seem that could take some time to get accurate results for the general population. And then we also have the variants of the virus to deal with too. Finally, I don't have any real perspective on the "absolute risk reduction, 0.7%" number in relation to other vaccines. It sounds very low, but the article doesn't offer comparisons to other vaccines.