Publications by authors named "Alexandra Melton"
The effects of immunodeficiency associated with chronic HIV infection on COVID-19 disease and viral persistence have not been directly addressed in a controlled setting. In this pilot study, we exposed two pigtail macaques (PTMs) chronically infected with SIVmac239, exhibiting from very low to no CD4 T cells across all compartments, to SARS-CoV-2. We monitored the disease progression, viral replication, and evolution, and compared these outcomes with SIV-naïve PTMs infected with SARS-CoV-2.
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- * A pilot study involved two pigtail macaques infected with SIV (a simian version of HIV), which were exposed to SARS-CoV-2 and monitored to observe clinical disease and viral behavior over six weeks, compared to non-SIV-infected macaques.
- * Despite lacking robust immune responses, the SIV-infected macaques showed similar patterns of viral replication and clearance as non-infected macaques, suggesting that their immunodeficiency didn't affect the progression or evolution of SARS-CoV-2. *
Article Synopsis
- Recent SARS-CoV-2 variants are more transmissible and can evade immune responses, making tracking their evolution essential.
- A study sequenced viral RNA from rectal swabs of African green monkeys infected with SARS-CoV-2 to understand its evolution in nonhuman primate models.
- Two key findings emerged: mutations in the furin cleavage site were absent in the monkeys, indicating its importance for infection, and three specific amino acid changes were consistently found in all samples, suggesting a possible host-adapted variant for future research.
The novel coronavirus SARS-CoV-2, the causative agent of COVID-19 disease, has killed over five million people worldwide as of December 2021 with infections rising again due to the emergence of highly transmissible variants. Animal models that faithfully recapitulate human disease are critical for assessing SARS-CoV-2 viral and immune dynamics, for understanding mechanisms of disease, and for testing vaccines and therapeutics. Pigtail macaques (PTM, Macaca nemestrina) demonstrate a rapid and severe disease course when infected with simian immunodeficiency virus (SIV), including the development of severe cardiovascular symptoms that are pertinent to COVID-19 manifestations in humans.
View Article and Find Full Text PDFMany countries in sub-Saharan Africa have experienced lower COVID-19 caseloads and fewer deaths than countries in other regions worldwide. Under-reporting of cases and a younger population could partly account for these differences, but pre-existing immunity to coronaviruses is another potential factor. Blood samples from Sierra Leonean Lassa fever and Ebola survivors and their contacts collected before the first reported COVID-19 cases were assessed using enzyme-linked immunosorbent assays for the presence of antibodies binding to proteins of coronaviruses that infect humans.
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