Fact sheet published by the World Health Organisation shows that the diseases listed in the claim cannot be linked specifically to the election years.
From the above links, we can point out inaccuracies as the dates of major disease outbreaks do not match with election years presumably in the U.S. There is also no clarity on whether the claim speaks about the identification or date of the outbreak. Though some of the diseases occurred during U.S. election years including midterm elections, most of the outbreaks are misleadingly connected to the years listed in the claim.
SARS was identified in 2003, not 2004, Avian Flu in 2003, not 2008, Zika was 2015, not 2016. Likewise, Swine Flu was declared a pandemic in 2009, not 2010, and Covid-19 was first identified in the year 2019. Also, the claim that outbreaks can be planned during election years has no scientific basis.
The COVID-19 pandemic has given rise to a lot of potentially dangerous misinformation. For reliable advice on COVID-19 including symptoms, prevention and available treatment, please refer to the World Health Organisation or your national healthcare authority.