INFLUENZA, AN EVER-CHANGING VIRUS

Influenza, or the flu, is a highly variable virus that changes constantly. Through ongoing mutations on its surface antigens, the virus is able to evade the body’s immune system and cause infection.

Each year, over 600 million people are infected with the flu. An annual flu shot is necessary to prevent influenza because the composition of the vaccine changes from year to year to match the strains of virus in circulation. Influenza viruses mutate so quickly that they can render one season’s vaccine ineffective by the next season.

Because the virus evolves with each new flu season, each year in September and February, the World Health Organization issues recommendations concerning the composition of the flu vaccine for the next season, which normally begins in May-June in the southern hemisphere and November-December in the northern hemisphere.

Different Faces of Flu

Human or seasonal

Human or seasonal is a highly contagious disease caused by the influenza viruses. It is transmitted from person to person through infected secretion droplets spread by coughing or sneezing. Each year the World Health Organization (WHO) issues the recommended vaccinate formulation to target the most widely circulating strains of the year.
The seasonal influenza vaccine does not protect against avian influenza infections in humans.

Pandemic

A pandemic is a worldwide epidemic. An influenza pandemic could occur approximately every 10 to 40 years. It can cause high levels of illness, death and economic loss. It may start when a new virulent influenza virus emerges, against which the population has no immunity. To create a pandemic, this new virus should be highly pathogenic and able to spread easily among humans.
The most infamous pandemic was “Spanish ” which affected large parts of the world population and is thought to have killed at least 40 million people in 1918-1919. More recently, two other influenza A pandemics occurred in 1957 (“Asian influenza”) and 1968 (“Hong Kong influenza”) and caused significant morbidity and mortality globally. In contrast to current influenza epidemics, these pandemics were associated with severe outcomes also among healthy younger persons, albeit not on such a dramatic scale as the “Spanish ” where the death rate was highest among healthy young adults.

The last pandemic occurred in 1968. The longest interval between pandemics is 39 years, so it is possible that another pandemic will happen in the near future. The pandemic clock is ticking, we just don’t know what time it is.

Avian

Avian influenza is an infectious disease of birds caused by type A strains of the influenza virus. The disease occurs worldwide. Although avian influenza mainly affects wild aquatic birds, domestic poultry may also develop the disease. The avian influenza virus has infected humans on rare occasions

Visit Bakuna.ph for more Info’s. about Flu