Growing Flu Vaccines Inside Eggs Makes Them Less Effective

Flu vaccines have become less and less effective over the years, and researchers have now finally offered an answer to why this happens. The method used to prepare the shots has a huge influence on their effects, so this might be to blame for their reduced effectiveness. Therefore, a recent study has revealed that they aren’t as good anymore because they’re grown inside eggs.

Mutations reduce the performance of flu vaccines

The study revealed that those flu vaccines grown inside chicken eggs have more mutations. These mutations increase the likelihood of the virus to get attached and develop inside chicken cells. This ease to attach and infect is given by a special compound found in viruses, called hemagglutinin.

Usually, flu vaccines target this compound and try to annihilate it. However, if the virus is able to undergo mutations, then the vaccine can no longer fight against it. Growing vaccines inside eggs doesn’t help, as it seems that the virus they contain builds up a sugar compound on top of the hemagglutinin. Once this happens, the shot becomes ineffective.

It’s easier for viruses to mutate while growing inside eggs

Researchers know that the process of developing flu vaccines is quite slow and complicated. Also, viruses keep evolving and, every year, they need to add something more to the shots to make them capable of dealing with the mutations.

In fact, growing flu vaccines in eggs facilitates mutations. Any shot contains an attenuated version of the virus, and this virus is the one which needs growing. However, to cultivate them in eggs requires the viruses to get adapted to this environment. In order to do this, it needs to undergo some mutations, which renders the vaccine ineffective even from the beginning.

This has been common practice for about 70 years, but the viruses never stopped evolving. Over time, they grew stronger, and kept undergoing mutations while inside the eggs. This reduced the performance of flu vaccines, so it suggests that researchers need to find new methods to produce shots.
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