People infected with Influenza A and B exhibit the following symptoms within 2-5 days of contact with the virus:

• Fever greater than 39.0 °C;
• Cephalalgia (headache), myalgia (muscle aches), arthralgia (joint pain), dysphagia (throat ache);
• Marked asthenia (weakness);
• Dry cough, rhinorrhea (watery nasal secretions);
• Shivers;

In cases of bacterial superinfection, the cough becomes productive and nasal secretions change appearance and consistency, a situation in which antibiotic drug treatment is required.

Influenza C infection is manifested by very attenuated cold-specific symptoms similar to the common, trivial cold.