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The days are getting shorter and it’s cold and windy outside. As with every year, it’s that time again when we are at greater risk from catching coughs and colds. Meanwhile, doctors in the Northern Hemisphere are advising people to get their flu vaccination in time. This year however, they are strongly recommending it, as they understand the potential hazards. This year’s influenza season south of the Equator has been severe. The flu virus spreads to an alarming degree and could well cross to North America, Europe and to Northern parts of Asia as well.
Image source: Jarun Ontakrai/shutterstock.com
During the Australian winter season from June to August, 2.5 times more people were infected with flu than in the year before. Also, besides the huge overall increase in infections, the Australians have observed that one of the current influenza strains seems to recently have mutated and become more aggressive. Even middle-aged people and children, without any previous medical problems have died, as well as hundreds of elderly people in care homes. Doctors assume that the actual flu vaccine is probably not working so effectively against this aggressive flu mutant, which the media have already nicknamed “The Killer Strain”.
What is flu and what makes it as serious?
Flu is an infection whereby influenza viruses are spread through airborne infection. Typical symptoms include a sudden high fever, serious headaches, sinus pressure, fatigue and dull pain. However, every flu infection also carries the risk of serious complications, hospitalization and death. Flu may cause severe illness, such as pneumonia, heart muscle inflammation or meningitis.
So, what happens during flu? Initially, the disease starts through inhaling the influenza viruses which infect the upper and lower respiratory tract. The virus eliminates the protective mucus coating of the cells, before docking onto their surfaces and penetrating them. Inside the cell, the virus starts to replicate by using the components of the host cells to make pathogen proteins. The infected cells die and release millions of new viruses that infect other cells. While the influenza virus rapidly multiplies, the body activates its own immune defense. Scavenger cells start the fight against the virus, the body temperature rises, mucus accumulates in the bronchia and secondary diseases as well as subsequent bacterial infections may take their course.
Mutability is the challenge
Influenza viruses belong to the most adaptable pathogens at all - they are the chameleons of the viral world. Several subtypes are known and these are subject to continuous genetic mutation. For optimal protection, it is therefore vital to get a specifically tailored vaccination every year.
The World Health Organization, WHO and national health authorities provide clear vaccination recommendations: people of 60 years old and above, the chronically sick, pregnant women and medical professionals should receive an annual flu vaccination. However, even timely vaccination cannot provide 100 % protection against influenza infections. Because production of the vaccine takes many months, it must already be produced well in advance. It is therefore unclear whether the vaccine will fully reflect the composition of the season’s flu viruses.
The flu vaccine
Despite this, flu vaccination is the most effective way to protect individuals from serious infections.
The most common method to produce flu vaccines is using specific, pathogen-free eggs. The eggs are infected with the influenza virus to multiply the virus material on an industrial scale. For this purpose, the WHO sends out a combination of specifically selected seed viruses to the vaccine manufacturers each February. These seed viruses represent the three or four most common, or potentially new, virus subtypes from the last flu season. The production process, including clinical studies, takes about 6 months to complete.
The fear of pandemics
Influenza is a global issue. Worldwide, about 3-5 million people are infected with influenza annually and of these 50.000 – 500.000 die as a consequence. Moreover, there have been some terrifying pandemics in the past. In the 1950s and 60s, for example, about 2 million people died through two flu pandemics. Worse still, was the outbreak of “Spanish Flu” of 1918/19, which accounted for more than 50 million deaths.
Although these are dramatic single instances, some experts warn that huge pandemics can occur at any time. This year could also be a bad one too, with the southern hemisphere flu season giving us cause for concern.
However, you can make your own personal contribution to preventing a new flu pandemic: Get your vaccination in time, stay away from ill people and wash your hands frequently.