Pandemics: Unpredictable, But Another Caused By A New Influenza Virus is a Certainty

Pandemic influenza outbreaks are unpredictable. One million people around the world died in a 1957 outbreak that started in China but spread globally. In 1968, another outbreak took an estimated 1-3 million lives. In 2003, the re-emergence of A(H5N1) or so-called avian influenza, highlighted how the virus could pass from animals to people, but it did not reach the pandemic stage because it could not pass sustainably from person to person.

When 100 passengers on a flight from Dubai to New York in September 2018 fell ill with respiratory symptoms, health officials were concerned that they might be carrying a serious respiratory illness called MERS-CoV (Middle East respiratory syndrome coronavirus) and quarantined the plane until further health checks could be completed. Testing showed that several were positive for the influenza virus, which can be easily spread when people are in close contact or in contained spaces such as airports and planes for several hours.

Influenza may not always be thought of by most people as a serious illness – the symptoms of headaches, runny nose, cough and muscle pain can make people confuse it with a heavy cold. Yet seasonal influenza kills up to 650 000 people every year. That is why influenza vaccinations are so important, especially to protect young children, older people, pregnant women, or people who have vulnerable immune systems (click here for a Facebook live with Dr Martin Friede on the flu vaccine).

What most of us think of as ‘the flu’ is seasonal influenza, so called because it comes around in the coldest season twice a year (once in the Northern hemisphere’s winter, and once in the Southern hemisphere’s winter) in temperate zones of the world, and circulates year-round in the tropics and subtropics.

The influenza virus is constantly mutating – essentially putting on ever-changing disguises – to evade our immune systems. When a new virus emerges that can easily infect people and be spread between people, and to which most people have no immunity, it can turn into a pandemic. “Another pandemic caused by a new influenza virus is a certainty. But we do not know when it will happen, what virus strain it will be and how severe the disease will be,” said Dr Wenqing Zhang, the manager of WHO’s Global Influenza Programme. “This uncertainty makes influenza very different to many other pathogens,” she said.

edictably unpredictable

For the study, Visit WHO