This is a really good point. Imagine if in six months, the CDC was discovered to have had covered up a dozen deaths and a hundred blood clot cases caused by the vaccine after insisting the vaccine is completely safe the whole time in order to not pause vaccine distribution. People already get on the CDC's case on change in stance in wearing masks last year. A direct cover up on deaths (even if the number of deaths is small) would severely damage the CDC's reputation and public's trust in vaccines in the future. It's better to take a week break, be open and honest and assess risks vs benefits of the vaccine, and adjust recommendations if necessary.