Which statement best explains why the influenza vaccine must be updated every year?
1 point
Some years, the influenza vaccine is not as strong as in others.
Some years, the influenza vaccine kills the virus, while in other years it does not.
The influenza virus adapts and mutates every year, so new vaccines must be produced.
The influenza vaccine does not necessarily stimulate the immune system to produce antigens.
The influenza virus adapts and mutates every year, so new vaccines must be produced.
The statement that best explains why the influenza vaccine must be updated every year is: "The influenza virus adapts and mutates every year, so new vaccines must be produced." To understand why this is the case, we need to consider the nature of the influenza virus.
Influenza viruses are constantly changing and mutating, which means that new strains of the virus can emerge each year. This is known as antigenic drift. These changes can affect the surface proteins of the virus, particularly the hemagglutinin (HA) and neuraminidase (NA) proteins. These proteins are targeted by the immune system in response to infection.
The influenza vaccine works by introducing small, harmless pieces of the virus or weakened versions of the virus into the body. This stimulates the immune system to produce antibodies that can recognize and neutralize the virus. However, if the virus undergoes significant changes in the HA and NA proteins, the antibodies generated by a previous vaccine may not effectively recognize the new strains.
To ensure that the vaccine remains effective, scientists continuously monitor the circulating strains of influenza viruses worldwide. Based on this surveillance, they update the vaccine each year to include the most likely strains that will be circulating in the upcoming flu season. By doing so, the vaccine can provide optimal protection against the most current strains of the influenza virus.
Therefore, the need to update the influenza vaccine every year is driven by the constant adaptation and mutation of the influenza virus, ensuring that the vaccine remains effective in preventing infection and reducing the severity of illness.