Question: I want to be a medical researcher in immunology and genetics. I am not sure if you have to go to med school to be a medical researcher or if you just have to major in biology. Please help me to clear up this confusion.
You may take a number of roads to reach your goal in research. You don't have to be an MD to do the research. However, there are quite a few doctors doing research today, especially at the premier research facilities around the world.
Perhaps the most traditional path for you may be to get your undergraduate (UG) degree in some form of life science, such as molecular biology or any of the other subsets of biology or chemistry. A quality UG college or university should give you the opportunity to do research with tenured faculty, which will be the first important step for you to find out if the rigors of research are right for you. If you are determined to become an MD, you could try for one of the very prestigious (and super-competitive) college-medical degree programs, such as Brown's PLME program. See:
Or, more traditionally, with your UG degree in hand, perhaps you can land a graduate fellowship that would allow you to work with precisely focused experts in the fields of immunology or genetics. Your move to this level should put you at an institution where there are plenty of opportunities to network with many others in your chosen specialty. After your Masters work, you can choose to go for a doctorate (Ph.D.) or go on to medical school, to which you can go directly from you UG program.
There are no doubt other paths you can take, but the bottom line is that you don't have to be an MD to do research in these fields. However, you may find that you like the challenge (and long hours) of the medical-doctor route. The less-difficult routes can get you where you want to be too, but which one you choose will be determined by your resolve, willingness to fulfill rigorous requirements, and, of course, your financial circumstances.