HOW MANY TYPES OF VIRUS EXIST is a different question from how many individual viral particles exist (10(31)). “At present only a small part of the total diversity of viruses has been studied, with analyses of samples from humans finding that about 20% of the virus sequences recovered have not been seen before, and samples from the environment, such as from seawater and ocean sediments, finding that the large majority of sequences are completely novel.” The large majority! https://lnkd.in/eF3wTsF View in LinkedIn