An observational study in SARS CoV 2 Infection and SARS CoV 2 Vaccination, sponsored by Boston University. Recruiting at 2 sites in 2 countries. Open to participants aged 5 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-05-28.
Sponsored by Boston University · Observational
SARS-CoV-2 transmission was expected to have a devastating impact in sub-Saharan African countries. Instead, morbidity and mortality rates in nearly the whole region are an order of magnitude lower than in Europe and the Americas. To identify what is different requires a better understanding of the underlying immunological substrate of the population, and how these factors affect susceptibility to infection, progression of symptoms, transmission, and responses to SARS-CoV-2 vaccination.
Study objectives
The investigators hypothesize that malaria and intestinal parasitic diseases may result in enhanced or tolerogenic innate immune responses that decrease the risk of symptomatic COVID-19. On the other hand, these conditions and deficiency of micronutrients may decrease the acquisition and longevity of antibodies induced by natural infection and SARS-CoV-2 vaccines, increasing the risk of re-infection and breakthrough infections to vaccination.
To test these hypotheses, up to 200 symptomatic individuals (index cases)will be enrolled, their household contacts (anticipated \~700), and up to 600 vaccinees. The specific innate immune phenotypes that differentiate uninfected Malawians from Western controls (based on samples from blood banks) and whether those responses are protecting Malawians from infection and/or progression of disease will be assessed. Infected participants and vaccinees will be followed for up to 1.5 years to assess acquisition and longevity of Ab responses and memory B cells.
7,990 studies on the registry are indexed under COVID-19; 466 are open to participants now.
This study's planned enrollment of 1,500 is above the median of 268 across 3,208 observational studies indexed under COVID-19.
Browse COVID-19 studies →Boston University is the lead sponsor of 270 studies on the registry; 36 are open to participants now.
Of its 31 completed or terminated interventional studies of FDA-regulated products, 24 (77%) have results posted.
Counted across the registry records on this site, refreshed daily.
This study will take place in Blantyre, in one or all of the following health centers and their catchment areas: Bangwe, Chileka, Chilomoni, and Mpemba. These health centers were chosen because transmission of SARS-CoV-2 and malaria were recorded in their catchment area in the past two years. If needed, to reach the recruitment target, different health services in Blantyre may be considered for this research.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Household Contacts of the Confirmed SARS-CoV-2 Case
Vaccinees
1) Aged 18 years to 75 years; 2) Willingness to receive the primary regimen of the AZ and/or JJ vaccines 2) Not in the other 2 cohorts; 4) Willingness to comply with study procedures and follow-up visits and provides informed consent.
5) Has not received a prior dose of a SARS-CoV-2 vaccine
Exclusion Criteria Index Cases
Household Contacts of the Confirmed SARS-CoV-2 Case
Vaccinees
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Up to 200 symptomatic subjects (index cases) will be enrolled when they seek diagnosis for their symptoms of COVID-19 and have their SARS-CoV-2 infection confirmed. All their household contacts (anticipated 700) aged 5-75 years who provide consent (participants) will be examined for infection through two consecutive SARS-CoV-2 RT-PCR. Blood will be drawn from all participants who provide consent. Venous Blood will be drawn at the first visit (so called W0). A second collection is planned for 15 days after the first visit, a third collection at three months after the first visit, and subsequent collections are planned at six, nine, and 15 months after the first visit. At the visits one month, nine months and 15 months after the first visit, capillary blood will be collected. A stool sample will be collected for diagnosis of intestinal parasites.
Up to 600 subjects 18-75 years will be recruited when they attend a vaccination clinic at one of the study health centers in Blantyre to receive their 1st dose of the AstraZeneca (AZ) or the Johnson and Johnson (JJ) COVID-19 vaccines. Venous blood will be collected at that time. For AZ vaccinees, at their 2nd vaccine dose, about 90 days after the 1st dose, they will be given a stool sample container. JJ vaccinees will receive the stool sample container when they receive the first vaccine dose. Two weeks after completion of the primary regimen (2nd dose of the AZ \[M3.5\] and 1st dose of the JJ vaccines \[M0.5\]), venous blood draws will be repeated and stool containers will be collected. Subsequent visits/procedures will happen at one month thereafter (M4.5 for AZ and M1.5 for JJ), and 3, 6, 9, and 12 months after the primary regimen. Venous blood will be collected at the visit 1.5, 3, 6, and 12 months after the primary regimen and capillary blood will be collected at the other visits.
Risk of asymptomatic infection among contacts who acquire infection
Proportion of household members who acquire an asymptomatic (vs. symptomatic) infection among household contacts of an index case
Time frame: up to 2 weeks
Duration of neutralizing antibody (NAb) responses against two viruses
Among participants who develop neutralizing antibody responses, days to decay antibody levels to a 25% level from baseline. NAbs levels, defined as dilution of serum or plasma required to inhibit 50% of virus entry into a target cell lines (ID50) will be measured against the vaccine matched viruses and an additional predominant circulating variant of concern at the time participant samples are collected.
Time frame: up to 15 months
Change in frequencies of classical (CD14+CD16-) monocytes and markers of activation/inflammation with and without stimulation by by toll like receptor (TLR) and retinoic acid-inducible gene I (RIG-I) like receptors (RLR) ligands
Difference between measures obtained at 2 weeks and baseline in percentage positive. Percentage positive can range from 0 to 100. Change = Percentage positive at 2 weeks - Percentage positive at baseline
Time frame: baseline, 2 weeks
Probably of infections in a household
Estimated probability of infection among household contacts of an index case
Time frame: up to 2 weeks
Duration of COVID-19 symptoms, reinfection rates, and breakthrough infection rates
Days to resolve symptoms in each symptomatic episode and number of confirmed SARS-CoV-2 infection through RT-PCR after a first infection or vaccination
Time frame: up to 15 months
Change in activation status of monocytes and monocyte-derived macrophages (MDMs) with and without stimulation with TLR and RLR agonists in vitro
Percentage positive of activation markers (CD169, CD86, and CD80) will be quantified by flow cytometry and can range from 0 to 100 of percent positive cells. Change = Percentage positive of CD169, CD86, and CD80 at 2 weeks - Percentage positive at baseline
Time frame: baseline, 2 weeks
Change in cell activation markers among stimulated and unstimulated classical monocytes and MDMs
Difference between measures obtained at 2 weeks and baseline in percentage positive of CD169, CD86 and CD80 expression will be measured quantified through flow cytometry. Change = Percentage positive of CD169, CD86, and CD80 at 2 weeks - Percentage positive at baseline
Time frame: baseline, 2 weeks
Change in concentrations of pro-inflammatory cytokines and chemokines produced by classic monocytes and MDMs
Difference between measures obtained at 2 weeks and baseline in concentration (median fluorescence intensity (MFI)) from M0 to M2 of chemokines and cytokines (e.g., MCP-1, IFNα, IFNβ, IFNλ, IP-10, IL-6, and IL-1 β) quantified through Luminex-based assays
Time frame: baseline, 2 weeks
Change in expression of 770 host response genes in classical monocytes and MDMs
Host gene expression will be quantitated through NanoString nCounter Infectious Disease Host Response Panel, focusing on Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and Interferon regulatory factor 3 (IRF3)-controlled dependent transcripts. Changes in gene expression will be reported as fold increase at 2 weeks over that observed at baseline
Time frame: baseline, 2 weeks
Antibody magnitude to 3 SARS-COV-2 antigens and 3 trimers
Concentration (in Optical Density) of Immunoglobulin G (IgG) against Spike (S) protein, Receptor binding domain (RBD), and Nucleocapsid based trimer (N trimers) based on the vaccine matched variant and two other circulating variants of concern will be measured by Enzyme Linked Immunosorbent Assay (ELISA))
Time frame: up to 12 months and 18 months, depending on the cohort
NAb responses measured against 3 viruses and through a surrogate assay (sENAB)
Inhibition of binding by RBD to ACE2 (ID50) receptor by plasma antibodies using a plate based surrogate neutralization assay.
Time frame: up to 12 months, 15 months
Fc-gamma receptors (FcγR) -II/III binding functional antibody activities
Binding activity (in Optical Density) of FcγR against S, RBD antigens based measured by plate-based assay
Time frame: 1 month
Duration of antibody-dependent cellular cytotoxicity (ADCC) responses
Using fresh Natural Killer (NK) cells that were incubated with interleukin 2 (IL-2), the investigators will quantify CD107a expression (determined by flow cytometry) by Natural Killer cells after incubation with opsonized antigen-coated beads (S antigen). Percentage of NK cells positive for CD107a
Time frame: up to 12 months
Magnitude of dimeric Immunoglobulin A (dIgA)
Binding activity (in Optical Density) of IgA against S, RBD antigens based measured by ELISA.
Time frame: 1 month
Frequencies of B (S-antigen specific and total) and plasma cells, and innate immunity parameters
Proportion of B cells (S-antigen and total) and plasma cells as a percentage of total B cells and total lymphocytes and innate immune parameters as a percentage of total immune cells at 12 and 15 months. Possible units can range from 0 to 16. Proportions will be compared between different patient groups, for example percentage positive in malaria uninfected compared to percentage positive in malaria infected patients.
Time frame: up to 12 months, 15 months
Not enrolling at this site.
Plan to share: No
No publications or documents are linked to this record.
Started Jan 2023 (actual). Primary completion is estimated for Mar 2028, 62 months after the start.
Of 1,640 non-industry observational studies under COVID-19, half reached primary completion within 14 months of starting (the median), counting those still running; a quarter within 5 and three quarters within 30. This study's planned 62 months is above that.
Counting every sponsor, half of 1,774 studies reached it within 13 months; a quarter within 5 and three quarters within 29.
How these figures are worked out, and which studies are left out of them.
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