No, not every U.S. election year has had a disease outbreak and COVID-19 transmissibility is unconfirmed
Every year in the U.S. is an election year, if taking into account midterm elections as well as presidential elections, and contrary to the claim, not every election year has had a disease outbreak, as implied in the claim. In addition, the transmissibility of the coronavirus, represented by the “basic reproduction number”, is still under study. Currently, the basic reproduction numbers reported for the virus causing COVID-19 range between around 2 to more than 6.