In this study we aim to characterize SARS CoV-2 strain specific immune response(SARS-CoV-2 Spike IgG) in health care workers and general populations at the JimmaMedical Center and the St. Paul Hospital in Addis Ababa in association to clinical immuneprotection and Covid-19 disease. Participants, stratified by SARS-CoV-2 infection andvaccination status, will be followed at 3-month intervals for a maximum of 2 years.Prevalence, incidence, and dynamics of SARS-CoV-2 specific antibodies as well as clinicalassessments especially related to COVID-19 breakthrough disease in previouslyexposed/vaccinated participants will be performed. From a subset of selected participantblood sample, more in depth immunological analysis will be performed that include virusculture-based neutralization assays, antibody avidity assays, SARS-CoV-2 specificantibody epitope recognition using peptide arrays, and T-cell immunity assays (IGRA).We also plan to analyze and model cost-effectiveness considerations related to adaptedCOVID-19 vaccine strategies, specifically if SARS-CoV-2 the costs for routinesero-diagnosis in high SARS-CoV-2 prevalent population prior to vaccination will impactthe decision to vaccinate (no vaccination for low-risk populations or reduced vaccinedosing) and is cost-efficient. The study is largely exploratory, providing deeperinsights in SARS-CoV-2 specific immune responses and interaction with SARS-CoV-2 viralvariants.
The COVID-19 pandemic has severely impacted health systems, interventions for infection
control and resulting preventive public life restrictions. In a recent study, we
determined high rates of previous SARS-CoV-2 infection in health care worker (over 70%)
and communities in Ethiopia (up to 60%), with resulting potential natural acquired
SARS-CoV-2 specific immunity. In contrast to the situation in Europe, the scale out of
COVID-19 vaccination is however very low, and currently there is a scarcity of COVID-19
vaccines available all over Africa. Naturally acquired or vaccine induced SARS-CoV-2
immune responses have shown to protect against (severe) COVID-19 disease. However, immune
responses are waning over time and new SARS-CoV-2 viral variants increasingly demonstrate
immune escape properties. Correlates of clinical immune protections are currently
investigated including binding SARS-CoV-2 spike IgG or neutralizing antibody levels, as
well as cellular immune responses. However, threshold of immune protection are not yet
defined that would guide the need of booster vaccinations, including for individuals with
natural acquired immunity. There is evidence, that vaccination regimens in those
individuals could be abbreviated to single shot booster, that would greatly economize
challenged COVID-19 strategies in Africa.
The CoVICIS is a network of European and African researcher who collaborate on the
overall objective to investigate SARS-CoV-2 specific immune response and correlates of
immune protection in the context of circulating SARS-CoV-2 viral variants. In this
affiliated study, we aim to investigate these outcomes in Ethiopian health care worker
and community members throughout a longitudinal, prospective cohort study. Participants,
stratified according to their SARS-CoV-2 infection and vaccination status, will be
followed-up in 3-monthly intervals To characterize SARS CoV-2 strain specific immune
response (SARS-CoV-2 Spike IgG) in health care workers and general populations stratified
by previous (1) SARS CoV-2 exposure (SARS-CoV-2 anti-nucleocapsid antibody positive
versus negative) and (2) vaccination status at the Jimma Medical Center (JMC) and the St.
Paul Hospital in Addis Ababa in association to clinical immune protection and Covid-19
disease. Prevalence, incidence, and dynamics of SARS-CoV-2 specific antibodies as well as
clinical assessments will be performed in 3-monthly intervals over a maximum period of 24
months.
At each study visits, immune responses including SARS-CoV-2 spike IgG and neutralizing
antibody will be measured. In addition, SARS CoV-2-specific T cell responses will be
studied in each of the study groups. COVID-19 disease or SARS-CoV-2 infections will be
assessed throughout the study by clinical history, SARS-CoV-2 PCR diagnostics, and
seroconversion of SARS-CoV-2 anti-nucleocapsid antibody testing as appropriate. In
addition, more in-depth analysis will be performed in a subset of stored blood samples at
collaborating specialized laboratories in Germany and Switzerland, including peptide
array mapping, T-cell assays and affinity/avidity analysis against the ACE-II receptor.
We further aim to characterize circulating SARS CoV-2 strains from PCR isolates in the
context of investigated immune responses. Outcome results will be provided for
computational analysis, integrating models for immune protection. Finally, we will
explore the feasibility and cost-effectiveness of abbreviated single shot COVID-19
vaccination for individuals with pre-existing natural immunity to assess COVID-19 vaccine
strategies that are especially applicable in African settings.
Findings from this study aim to help in guiding the current Covid-19 control strategy in
Ethiopia. It might also give the first insight about the dynamics and level of antibodies
produced against SARS-CoV-2 in the Ethiopian population.
Inclusion criteria:
1. Adults, 18 years of above
2. Provision of oral as well as written informed consent
3. Available estimation of the period or the time-point when SARS-CoV-2 infection
occurred (e.g. confirmed or highly suspected COVID-19 disease, SARS-CoV-2
anti-nucleocapsid seroconversion) (only applicable for participants included in
group 1 and 2).
4. Employed/working in hospital (medical doctors, nurses/midwives, students, auxiliary
personnel such as cleaner, runner, social worker) for HCW
5. Willingness to provide blood samples by venipuncture for serology and immunological
characterization
6. Willingness to provide health information, report medical events and to performed
SARS-CoV-2 diagnostics (swabs for PCR) in the case of suspected COVID-19 disease
Exclusion criteria:
1. Prisoners
2. Mentally disturbed persons
3. Persons for whom study participation will induce an unacceptable risk or burden as
judged by the investigator (e.g. seriously sick persons)
Department of Microbiology Immunology and Parasitology
Addis Ababa, Ethiopia
Jimma University
Jimma, Ethiopia
Arne Kroidl, MD
+49-89-4400 - 59816
Arne.Kroidl@med.uni-muenchen.de
Rebecca Kisch
Not Provided