Immunity: A new approach to the development of yellow virus vaccines.

Oct 4, 2020 /--- -- The results of a new study by researchers in health science at the University of Arizona are a step closer to developing an effective vaccine against the yellow virus.
when infected, the body produces antibodies to fight the virus and provide immunity against re-infection.
In the case of yellow viruses, however, if the human body is re-infected with the yellow virus (for example, they are initially infected by Zika and then dengue), the presence of antibodies can lead to more severe symptoms through an effect called antibody dependence enhancement (ADE).
(Photo: www.pixabay.com) "If you've been infected with the Zika virus in the past, the risk of serious illness increases significantly later when you're unfortunate enough to get dengue."
antibodies produced by memory B cells due to Zika virus infection can bind to certain parts of the dengue virus, but do not have the effect of killing the dengue virus.
," said Dr. Deepta Bhattacharya, an associate professor in the Department of Immunobiology.
, the antibodies produced by memory B cells can work like 'Trojan horses' and help the virus enter the cells, making the disease worse, " he said.
"s findings provide Dr. Bhattacharya and his team with a new way to think about the production of yellow virus vaccines.
they recommend designing not for the entire virus, but for the unique table of each type of virus.
, they will try to remove memory B cells.
. Bhattacharya, said, "We wanted to study how the immune system and antibody responses were treated for different types of yellow virus infections.
antibody-dependent increased response is the main reason for the difficulty of vaccine development against yellow viruses, especially dengue fever.
" results were published in the journal Immunity.
"memory B cells with limited affinity dominate the response to different types of yellow virus infection."
study focused on two types of antibody-producing cells: plasma cells and memory B cells.
cells are the main driver of long-lasting immunity because once the infection is cleared or vaccinated, they continue to produce antibodies.
and memory B cells produce antibodies only when a second infection occurs.
a long-standing question is, what is the purpose of those memory B cells? If you already have antibodies from plasma cells, why do you need other cells? Dr. Bhattacharya and his team used a combination of yellow virus infection, vaccination, and genetic mouse models to study the response of memory B cells to subsequent yellow virus infections.
they found that when memory B cells are activated by a new infection, they produce a variety of antibodies and are able to target viruses that have mutated since the first infection.
there is a lot of hidden diversity in the "memories" B cells.
is a good thing for most viral pathogens, such as influenza or SARS-CoV-2.
means that memory B cells are ready to make new antibodies and respond to mutations.
," Dr. Bhattacharya said.
, however, this is not a good thing for yellow viruses.
found that memory B cells produce many poor-quality antibodies that trigger the ADE effect.
"Although memory B cells are capable of producing new viruses and antibodies, these antibodies do not prevent new viruses from infecting cells."
, they may actually make a second infection worse.
the same is true when you are vaccinated.
the vaccine is designed to stimulate the immune response and encourage plasma and memory B cells to produce antibodies against the virus.
if people who have never been infected with dengue fever are vaccinated and produce antibodies, followed by another yellow virus, the antibodies produced by memory B cells after vaccination may increase the severity of the disease.
(bioon.com) Source: Researchers identify new target for creating flavivirus vaccines Original source: Rachel Wong et al, Affinity-Restricted Memory B Cells Dominate Recall Responses to Heterologous Flaviviruses, Immunity (2020). DOI: 10.1016/j.immuni.2020.09.001.