I think it's because all the contents used in your paper have been studied by others. I'm also doing a paper on viruses now. I wrote a technical outline about viruses similar to yours in my thesis, but my tutor didn't read those. He only asked me what I did, mainly what I did. But coincidentally, I also started with the "panda burning incense" virus! ^_^

In the thesis, it should be almost enough to mainly write out what you have done. Come on! ! ! ^_^