Immunity to SARS-CoV-2 in Africa

Continuing epidemic waves of COVID-19 are anticipated in
many countries because of emerging viral variants, the moderate
efficacy of vaccines being implemented in many countries,
waning immunity and incomplete vaccine coverage. 

The protective efficacy and longevity of immune responses induced
by SARS-CoV-2 infection and vaccines vary markedly between
individuals and populations. Knowledge on immunity to SARS-CoV-
2 in African populations, and factors that impact on
immunity, is very limited but is important for understanding
COVID-19 morbidity and prevention in the Africa region and globally. Repeated exposure to malaria, intestinal parasites, and respiratory viruses, as well and specific nutritional deficiencies are common in sub-Saharan Africa, and can impact on innate and adaptive immunity to influence the magnitude and longevity of immunity.

As part of an international collaborative program, this project
will investigate immunity in cohorts of naturally infected and
vaccinated individuals in Malawi (central Africa) and address
important knowledge gaps. The project will involve laboratory based
studies in Melbourne that assess the acquisition and
longevity of immunity generated by SARS-CoV-2 infection and
vaccination and determine how malaria and intestinal parasite
infections, undernutrition, and anemia impact on immunity. 

We will use a comprehensive range of immunoassays including
quantification of antibody magnitude (subclasses and isotypes),
neutralizing antibodies to different variants, avidity and
antibody-dependent cellular cytotoxicity. Additionally, studies
will profile specific epitopes targeted by immunity and their
relationship to immune escape by virus variants. 

The overall objective of this work is informing strategies to improve
protection from COVID-19, and identifying those most at risk,
by understanding key gaps in natural and vaccine induced
immunity.