Geoff said:
And there are 5,550,000 entries for "viruses" so if your criterion
for correct usage is frequency of occurrence, then viruses wins.
Language doesn't work like that, unless you are a school teacher.
English especially. A language can and will contain variant spelling of
many words (is it thru or through?) and real people have no problem with
this. Even dictionary compilers have no problems with it.
That just leaves the anally retentive language lawyers.
The Queen has nothing to do with it. Virus is Latin.
See below.
Again this is not how language works. What is the plural of octopus?
The dictionaries records 'octopi', however octopus is a Greek word and
should take a Greek ending; 'octopodes' but it has a Latinate ending -
tough; your petty rule is broken, get over it.
A language, its vocabulary, its grammar, its conventions, are all
arrived at by common usage even if this means accommodating multiple
spelling and overlapping usage.
And then there is jargon (professional or slang, it matters not).