Immunology Question

Arthropod-borne viruses(arboviruses)posea majorandglobal threat to human health, aided and abetted in

widespread and efficient transmission by their formidable mosquito vectors. While there are multiple viruses that
fall under this category worldwide, only a small proportion cause human disease.
In the Americas the region covering South, Central, and North America, and the Caribbean Islands the
increasing incidence and expanding geographic reach of arboviruses pose a growing and significant public health
challenge. Of greatest concern are the most prevalent of the arboviruses: dengue virus, chikungunya virus, and
Zika virus. How do these viruses cause disease and what are their clinical manifestations? How does our immune
system combat these viral infections? How do we test for and treat arboviral diseases? Are vaccines available for
any of these viral diseases or are they still in the developmental pipeline?
Arboviral infections have clinical and laboratory features similar to COVID-19, SARS-CoV-2, and influenza virus,
which can complicate treatment, especially in regions where only limited access to well-resourced testing and
treatment facilities might be available. What factors could pose additional challenges to disease control, and how
can some of these obstacles be overcome?
Arboviruses can be imported from endemic areas into non-endemic countries by infected travellers and may
establish new areas of local transmission in the presence of vectors and a susceptible population. Diseases caused
by dengue, chikungunya, and Zika viral infections are transmitted to humans through bites of infected mosquitoes,
primarily females of the Aedes genus (mainly, Aedes aegypti). Does this mean that vector-borne diseases might
be easier to prevent and control when the vector is targeted instead of the virus, or is it more complicated than
that? Recent advances in scientific technologies like genome sequencing and transcriptomics have increased our
understanding of vector biology, especially A. aegypti. What anti-arboviral immune responses are activated in
mosquitos? Are they immune tolerant to arboviruses? Could our knowledge of mosquitoes on a molecular level
help in treatment of arboviral diseases in humans?
Arboviral diseases are currently considered one of the greatest public health concerns in the Americas. To
underscore this growing concern, in March 2022, the World Health Organisation (WHO) launched the Global
Arbovirus Initiative, “an integrated strategic plan to tackle emerging and re-emerging arboviruses with epidemic
and pandemic potential, focusing on risk monitoring, pandemic prevention, preparedness, detection and response,
and building a coalition of partners”. In March 2023, the WHO reported increased transmission and expansion of
dengue and chikungunya cases outside of their historic areas of transmission in Central and South America and
the Caribbean. Even higher transmission rates are expected in the summer of 2023 due to weather conditions
favouring vector proliferation. Climate is closely linked to the ecological range, population dynamics, and disease
transmission rates of mosquitos. Northwards habitat expansion of some Aedes genus mosquitoes has already
been established from the United States into Canada, despite the harsh Canadian winters which would typically
be detrimental to mosquito reproduction. What would be the impact of climate change, warmer seasonal
temperatures, and extreme weather events, on the incidence and spread of arboviral diseases? What could this
mean in terms of the burden to public health?

Format: Your paper can
refer to any assigned course content (required/recommended readings (e.g., papers, textbook), references
provided on slides), or additional references that you find on your own. Please do NOT reference lecture slides.
Assignment Content: Your assignment can be approached in several ways, including (but not limited to) the
above prompts where you can focus on the:
1. Pathogenesis of arboviral diseases with a focus on 1 to 2 arboviruses (either dengue, chikungunya, or Zika
virus). How do these viruses cause disease and what are their symptoms? You should include a discussion of
anti-arboviral immune responses in humans. Consider how immune responses might differ in healthy versus
immunocompromised populations, and what that might mean in terms of treatment.
2. Transmission in endemic versus non-endemic regions of the Americas. What roles do vectors play and how
does our understanding of vector biology help in combatting and controlling arboviral diseases?
3. Epidemiological factors determining arboviral occurrence rates, distribution, and control of spread in
endemic compared to non-endemic regions. Do historical trends match what we are currently seeing?
Discuss the factors that might be contributing to changes in the epidemiology of arboviruses and their
vectors.
4. Focus on the treatment and prevention of arboviral diseases. What antiviral therapies are currently used to
treat patients with arboviral infections? What might be done to protect people from infection in the first
place? Do vaccines against arboviruses exist, or can we leverage our knowledge of mRNA vaccine technology
developed against COVID-19 to target arboviruses?