In 1918 a particularly virulent strain of influenza (an RNA virus) wiped out millions of health humans in the prime of their lives. Epidemiologists fear that such a super bug could revisit us in the future. And thus there was quest to find samples of the virus, and make a vaccine against it.
a)Explain why the fears of a recurrence are real.
b)Explain how they could find, isolate and make a vaccine for the 1918 strain.
c)Explain how the vaccine can help produce a humoral immunity.
Please help :)
a) The fears of a recurrence of a particularly virulent strain of influenza like the one that occurred in 1918 are real due to several reasons. Firstly, influenza viruses have the ability to undergo changes through a process called antigenic drift and antigenic shift. This means that they can change their surface proteins, particularly the hemagglutinin (H) and neuraminidase (N) proteins, making it easier for them to evade the human immune system and cause severe illness. Secondly, influenza viruses can also undergo reassortment, which occurs when two different influenza viruses infect the same host cell and exchange genetic material, creating a new strain with the potential to cause a pandemic. The 1918 influenza virus was an example of such a reassortment, which resulted in a highly pathogenic and transmissible strain. Therefore, the continuous evolution of influenza viruses and the potential for new reassortment events make it possible for a similar super bug to emerge in the future.
b) To find, isolate, and make a vaccine for the 1918 strain, scientists rely on several approaches. Firstly, archived samples of the virus can be obtained from reliable sources such as preserved lung tissues from victims of the 1918 influenza pandemic. These samples can be used to extract the viral RNA and sequence its genome. By comparing the genome of the 1918 strain to other influenza strains, scientists can identify the unique genetic characteristics that made the virus deadly. Secondly, once the viral genome is sequenced, scientists can use reverse genetics techniques to reconstruct a functional copy of the virus in a controlled laboratory setting. This enables them to study the virus, understand its properties, and develop diagnostic tools and vaccines. Finally, to create a vaccine, the scientists can grow the virus in a laboratory, inactivate it, and formulate it into a vaccine that can trigger an immune response without causing illness. This process involves ensuring the vaccine is safe, effective, and capable of inducing a protective immune response in recipients.
c) The vaccine for the 1918 strain, or any other influenza strain, can help produce humoral immunity. Humoral immunity involves the production of antibodies, which are proteins produced by specialized cells in the immune system called B cells. The influenza vaccine contains fragments of the viral proteins, such as the H and N proteins, or viral surface proteins. When the vaccine is administered, these viral fragments stimulate the B cells to produce specific antibodies against the influenza virus. In the case of the 1918 strain, the vaccine would induce the production of antibodies specifically targeting the H and N proteins of that strain. These antibodies circulate in the bloodstream and can bind to the surface proteins of the actual influenza virus if a person is exposed to it. The binding of antibodies to the virus prevents the virus from infecting host cells, neutralizing its ability to cause illness. In this way, the vaccine-induced humoral immunity provides protection against the specific strain of influenza included in the vaccine.