He didn't cut CDC funding. He submitted BUDGET PROPOSALS which reduced funding. The PROPOSAL WAS NEVER ENACTED.
just for reference, Obama also submitted multiple budget proposals that reduced CDC funding.
"After weeks of criticism, the Trump administration has reversed course on its request to cut funds for the Centers for Disease Control and Prevention (CDC) and the National Institute of Allergy and Infectious Diseases (NIAID) in its 2021 budget."
Keywords = REQUESTS to cut funds
In fact, the CDC's budget is now larger than when Obama was President.
"But here's the reality: the CDC's budget is now more than 7 percent larger than it was under President Obama's last two budgets. That is, the actual enacted program budgets for the CDC in 2016 and 2017 were both under $7.2 billion, but for 2020 the budget Congress adopted for it is nearly $7.7 billion."
https://mises.org/wire/cdcs-budget-larger-now-under-obama
"Under Obama’s proposal, the Centers for Disease Control and Prevention would take a $660 million cut to its budget authority. Some of that loss would be made up by taking money from the Prevention and Public Health Fund and fund transfers from HHS, so in the end the cut to CDC would be about $220 million."
http://thenationshealth.aphapublications.org/content/42/3/1.2