Type B Flu Symptoms 2024. Past flu seasons plus icon.  — b/yamagata flu viruses have not circulated in the population since march 2020, so protection from trivalent and quadrivalent flu vaccines is expected to be similar.

 — b/yamagata flu viruses have not circulated in the population since march 2020, so protection from trivalent and quadrivalent flu vaccines is expected to be similar. Common symptoms from an infection can include: