How do scientists know how to make a flu vaccine if viruses can be different every year?
he flu virus changes every year. However, scientists gather information about virus mutations, or changes, before the flu-virus season begins. This lets them predict what each year’s flu virus might look like. Based on that, a vaccine is made that we hope will be accurate enough to help people fight off major cases of the flu.
Scientists know how to make a flu vaccine even though the flu virus can be different every year because they use a process called surveillance. Surveillance involves monitoring and collecting data on the different strains of the virus that are circulating. This data is collected from around the world through a network of laboratories and health organizations.
To make a flu vaccine, scientists first analyze the genetic information of the different flu virus strains that are circulating. They look for specific changes in the genes of the virus. These changes are known as mutations and they occur naturally as the virus replicates and spreads.
Once the scientists have identified the specific mutations in the flu virus strains, they try to predict which strains are most likely to cause illness in the upcoming flu season. This prediction is made based on various factors, including how the virus has been evolving and spreading in different parts of the world.
Using this information, scientists select a few strains of the flu virus that they believe will be the most common and harmful in the upcoming season. They then use these strains to create a vaccine by growing the viruses in eggs or cells. The vaccine is usually a mixture of different virus strains.
When a person receives a flu vaccine, their immune system recognizes the viral proteins in the vaccine as foreign and mounts an immune response. This response produces antibodies that help the body fight off the flu virus if they are exposed to it later on.
It's important to note that the flu vaccine is not always a perfect match for the circulating strains of the virus. Sometimes, unexpected strains can become more dominant, or the viruses can mutate further after the vaccine has been manufactured. However, even if the vaccine is not an exact match, it can still provide some level of protection and reduce the severity of symptoms.
In summary, scientists use surveillance to monitor and collect data on the different flu virus strains that are circulating. They analyze this data and predict which strains will be the most common in the upcoming flu season. Based on these predictions, they create a vaccine that contains weakened or inactivated forms of the selected strains. This vaccine helps the immune system recognize and fight off the virus if a person is exposed to it.