Influenza B Surge: Understanding the Rising Flu Trend and Its Impact

As flu season ramps up, the Centers for Disease Control and Prevention (CDC) has reported a notable surge in influenza cases. In the latest release of data, a 19% increase in flu infections was observed, underscoring the virus’s widespread impact.

Currently, the majority of flu cases are attributed to strains of influenza A. However, a shift is underway as influenza B begins to take hold. This variant, while typically less prevalent, has been consistently rising over the past three weeks, now accounting for approximately one-third of flu cases across the country.

Influenza B, although not as common as its counterpart, influenza A, is more frequently observed in children. Its seasonal pattern also differs; influenza A generally marks the onset of flu season during the early winter months, whereas influenza B tends to emerge later, often spreading in the early spring months.

Another key distinction between the two types is their range of hosts. Influenza B is exclusive to humans, whereas influenza A is capable of infecting both humans and various animals, broadening its potential impact.

Overall, influenza B is less common than influenza A, but B types are more common among children.

Influenza B also tends to hit later in the flu season. While influenza A usually kicks off flu season in the early winter months, influenza B typically spreads later, around early spring.

Another difference between the two types: While influenza B affects only humans, influenza A can infect humans and other animals.

Both influenza A and B have similar symptoms: fever, cough, sore throat, congestion, body aches, headaches and fatigue. However, influenza A is thought to cause more severe illness than influenza B, in general.

The annual flu vaccine protects against both types of flu.

There are also two other types of influenza — C and D — but we don’t worry about them as much. Influenza C typically causes mild illness and doesn’t cause widespread epidemics, while influenza D mostly affects cattle.