This is Dr Basu, experienced Internal Medicine Specialist.
I am here to address your concerns and provide great service.
There are other cold viruses besides flu like adenovirus, norovirus etc.
Flu vaccine will not work against them.
Your son may have got one of these viruses.
Another possibility can be bacterial infection like streptococcal infection which will respond to antibiotic course
Hence, your son should see his doctor for throat swab.
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