Why can't the flu virus be eradicated?

Influenza viruses are constantly changing, creating new strains to replace old ones, because it is difficult to find a 100% effective vaccine that limits the proliferation of pathogens.

Many people think that the flu is not a serious problem. It causes discomfort for a few days, requiring a period of time off work or school. The US Centers for Disease Control (CDC) reports that from 2010 to 2020, the country had 342,000 deaths due to the flu. The flu is classified as "the most pandemic in history" , with millions of deaths.

In theory, eradicating the virus could prevent many deaths. But scientists say it is impossible to do so.

The reason is that the flu virus is constantly mutating, with thousands of variants and strains. If one strain of the flu virus disappears, others will quickly replace it. When a new variant appears, the flu prevention method must also be quickly updated, including vaccines.

This is made more difficult by the time and complexity of vaccine production. To prepare for flu season, for example, experts have to predict which strains will dominate next season, put them into vaccines, and roll them out. Sometimes they don't get it right, says Marc Jenkins, an immunologist at the University of Minnesota Medical School.

Illustration of a person with the flu. (Photo: Vecteezy).

Some years, the flu virus mutates so quickly that it outpaces the rate at which vaccines are made. By the time the shot is ready for widespread use, it is no longer effective against the latest variants. The strains of virus used to make the vaccine also mutate, making them unsuitable for use. As a result, the effectiveness of the flu vaccine hovers around 60%, leading many to believe that the shot is unnecessary.

Another, less likely scenario: science succeeds in developing a nearly 100% effective 'all-in-one' flu vaccine and everyone is vaccinated . However, this is not enough to eradicate influenza, because the virus can spread and mutate in animals, then infect humans. History records 16 flu variants from animals, infecting humans since 1958, and by 2009, the virus continued to mutate.

Therefore, medicine has shifted, advising people to prevent the flu instead of trying to destroy the pathogen. Vaccines help reduce the possibility of contracting the virus by 40-60%, avoiding severe infections and death, and preventing pandemics from happening.

In addition, flu vaccination also helps reduce mortality rates by 70-80%. Pregnant women who get flu vaccination reduce the risk of hospitalization by 40%; the risk of stillbirth by 51%, the risk of premature birth by 25%, and the risk of children under 6 months of age being hospitalized due to flu by 72%.

Flu vaccination should be repeated for people 6 months of age and older . Pregnant women who get the flu shot in the second or third trimester of pregnancy protect the mother and pass antibodies to the fetus, protecting the newborn until they are old enough to be vaccinated. In the elderly, the flu shot reduces the risk of hospitalization by 30 to 57%, and reduces mortality in people with cardiovascular disease.

In addition, when showing symptoms of the disease, people should avoid crowded places, wear masks, and avoid contact with high-risk people such as children, pregnant women, and the elderly. Patients should limit strenuous exercise, rest properly, and eat nutritious foods to help the body recover quickly.