NCT05973084 · Boston University
COVID-19 Transmission and Morbidity in Malawi
(COVID-TMM)
What this study is about
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.
View original scientific description
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 1. Determine the risk and predictors of infection and disease among contacts of SARS-CoV-2 infection subjects in Malawi 2. Determine whether innate immune responses lower the risk of SARS-CoV-2 infection and disease, and acquisition and duration of vaccine responses. 3. Assess whether alterations in innate immune responses relevant to SARS-CoV-2 are associated with malaria or intestinal parasite infections. 4. Assess the acquisition and longevity of antibodies (Ab) and cellular adaptive responses elicited by SARS-CoV-2 infection and vaccination. 5. Assess whether malaria and intestinal parasite infections, chronic/mild undernutrition, and anemia mediate alterations in Ab and other adaptive cellular responses to SARS-CoV-2 through innate immune responses or a different unknown mechanism.
Primary outcome measures
Risk of asymptomatic infection among contacts who acquire infection
Time frame: up to 2 weeks
Proportion of household members who acquire an asymptomatic (vs. symptomatic) infection among household contacts of an index case
Duration of neutralizing antibody (NAb) responses against two viruses
Time frame: up to 15 months
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.
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
Time frame: baseline, 2 weeks
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
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Index Cases
- Presents with symptoms of COVID-19 and has infection confirmed through RT-PCR or a rapid antigen test;
- Aged 5 years to 75 years and plans to live in Blantyre, in the catchment area of the target research health centers for the following 6 months;
- Confirmed SARS-CoV-2 infection and share a household with 1 or more individuals of eligible age;
- Has not received a SARS-CoV-2 vaccine in the previous 3 months
- Willingness to comply with study procedures and visits, and provides informed consent. Household Contacts of the Confirmed SARS-CoV-2 Case
- Aged 5 years to 75 years and plans to live in Blantyre, in the catchment area of the target research health centers in the following 6 months;
- Willingness to comply with study procedures and follow-up visits and provides informed consent.
- Has not received a SARS-CoV-2 vaccine in the previous 3 months 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
- Conditions that precludes from adherence to the visit schedule;
- 50% or more of household members decline to participate.
- Pregnancy at the enrollment visit
- Long term use of cotrimoxazole prophylaxis Household Contacts of the Confirmed SARS-CoV-2 Case
- Conditions that preclude adherence to the visit schedule.
- Participants with 2 consecutive negative SARS-CoV-2 RT-PCRs will be excluded from visits after M1.
- Pregnancy at the enrollment visit
- Long term use of cotrimoxazole prophylaxis Vaccinees
- Conditions that preclude adherence to the visit schedule.
- Pregnancy at the enrollment visit
- Long term use of cotrimoxazole prophylaxis
Where
- Boston, Massachusetts
Collaborators
National Institute of Allergy and Infectious Diseases (NIAID), Kamuzu University of Health Sciences, Burnet Institute
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced May 28, 2026 · Source of record for eligibility and locations