" Why are you multiplying the two numbers to get 19.2%???"
Because the two events are DEPENDENT, according to the wording in the article. Only 60% of Repubs got an initial vaccination. And OF that 60% only 32% got the boost. So the percent of ALL Republicans who are vaccinated + 1 time boosted is only 32% of the 60%. Put conversely, only 19.2% of Repubs are both initially vaccinated AND single boosted.
The follow on question on "intention" to get an *additional* boost is especially telling...almost as many as who got the 1st boost. Dems seem kind of addicted to boosts.
Best evidence says that each additional boost adds to the injury and, presumably, risk of death. So, if you keep getting boosted twice a year, you will eventually run out of "luck".
Now, it remains to be proven that damage compounds on damage, but there are some decent reasons to suspect that.