CLS is more hands-on and vocational than a biology or chemistry major. (IIRC, the last year of CLS is basically a full time internship.) CLS does, however, provide a better Plan B should med school not work out for you.
I think you need to backtrack a bit to look at potential career pathways. Epidemiology isn’t a medical specialty. It has it’s own career pathway that does NOT include medical school. Epidemiology requires a strong background in statistics/biostatistics and public health. Epidemiology jobs require a MPH, or a MS or a PhD in epidemiology.
Although entry into a MPH does not require any specific undergrad degree, you will need coursework in biology, chemistry, mathematics, statistics, public health, sociology and behavioral science. Some programs also like applicants to be comfortable using computer software like MATLab, R or SPSS.
Depending on the exact degree requirement at your undergrad, CLS may or may not provide you with an appropriate background for a MPH or epidemiology degree.
Pathology is a medical specialty and requires a MD or DO degree. CLS can be used as a stepping stone to med school; however, realize that vocational majors (like CLS, nursing, dietetics, or kinesiology) tend to do worse in med school admissions than do more academically oriented majors. Does this mean you won’t be able to gain a med school admission of you major in CLS? No, it just means a CLS major may make your road a bit more difficult. Med school adcomms also typically expected that those with vocationally oriented degrees to have worked in their career field for a few years before applying to med school so they can strongly articulate why they prefer a medical career over their major/current career.
In the end, the decision about what major to pursue as an undergrad is a very personal one, one that may involve a number of trade-offs.
If med school is your ultimate goal, then choose a major that will allow you the best opportunity to earn strong grades while also offering the best Plan B career alternatives.