An observational study in Group B Strep Infection, sponsored by St George's, University of London. Recruiting at 1 site in Uganda. Open to female participants. Per ClinicalTrials.gov, last updated 2026-05-01.
Sponsored by St George's, University of London · Observational
Collection of serum from women not living with HIV, who received the GBS6 vaccine in the "a placebo-controlled clinical trial investigating the safety and immunogenicity of GBS6 in pregnant women with and without human immunodeficiency virus (HIV) infection and their infants" (GBS6) Clinical Trial in Kampala, Uganda, for the Development of Group B Streptococcus quality assurance panel for the GASTON multiplex anti-CPS IgG immunoassay
This is a single-visit study designed to collect serum samples from women who previously participated in the GBS6 clinical trial, "A placebo-controlled clinical trial investigating the safety and immunogenicity of GBS6 in pregnant women with and without human immunodeficiency virus (HIV) infection and their infants" (GBS6 trial). The purpose of this follow-up study is to obtain serum samples for the development of Quality Control Sera (QCS) and Assay Bridging (AB) panels to support long-term quality control and performance monitoring of the GASTON immunoassay.
The GBS6 trial enrolled 300 pregnant women between October 2022 and July 2023 at Kawempe National Referral Hospital and Kisenyi Health Centre IV. The last participant completed follow-up on 23 October 2024. Of these, 150 participants (75 living with HIV and 75 not living with HIV) were randomized to receive either the GBS6 vaccine or placebo (normal saline). The GBS6 vaccine is a capsular polysaccharide conjugate vaccine targeting the six most common disease-causing GBS serotypes.
For this follow-up study, only participants who received the GBS6 vaccine and are not living with HIV (n=75) will be contacted via telephone using the contact details provided in the GBS6 trial records. Each consenting participant will attend a single study visit for serum collection. Collected samples will be shipped to the City, St George's laboratory for antibody screening. The GASTON assay will measure IgG concentrations for serotypes Ia, Ib, II, III, IV, and V. Based on these results, samples will be ranked by IgG values, and an appropriate pooling strategy will be developed to generate the QCS and AB panels.
146 studies on the registry are indexed under Streptococcal Infections; 14 are open to participants now.
This study's planned enrollment of 50 is below the median of 400 across 31 observational studies indexed under Streptococcal Infections.
Browse Streptococcal Infections studies →St George's, University of London is the lead sponsor of 106 studies on the registry; 12 are open to participants now.
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Women not living with HIV, who received the GBS6 vaccine in the "a placebo-controlled clinical trial investigating the safety and immunogenicity of GBS6 in pregnant women with and without human immunodeficiency virus (HIV) infection and their infants" (GBS6) Clinical Trial in Kampala, Uganda.
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.
Exclusion Criteria:
I. heart disease II. severe anaemia ( level less than 7.0g/dL)
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.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Women not living with HIV, who received the GBS6 vaccine in the "a placebo-controlled clinical trial investigating the safety and immunogenicity of GBS6 in pregnant women with and without human immunodeficiency virus (HIV) infection and their infants" (GBS6) Clinical Trial in Kampala, Uganda. The GBS6 trial enrolled 300 pregnant women between October 2022 and July 2023. Of these, 150 participants (75 living with HIV and 75 not living with HIV) were randomized to receive either the GBS6 vaccine (a capsular polysaccharide conjugate vaccine targeting the six most common disease-causing GBS serotypes) or placebo (normal saline). For this follow-up study, only participants who received the GBS6 vaccine and are not living with HIV (n=75) will be contacted via telephone using the contact details provided in the GBS6 trial records. Each consenting participant will attend a single study visit for serum collection.
Other: Collection of 50mls of blood
50mls of blood will be collected from all participants who give consent.
Creation of a quality control and bridging panels for the GBS multiplex immunoassay (GASTON assay)
Approx 50mL of blood will be collected from each study participant and will be used only for the development of QCS and AB panels. Blood samples will be processed and serum stored at -20C in Kampala, Uganda. The serum will be transferred to the City St George's, University of London laboratory, in the United Kingdom (UK), where the serum will be assayed for GBS6 serotype-specific anti-capsular antibodies using the GASTON multiplex anti-CPS IgG immunoassay. Concentrations of anti-capsular IgG for the 6 serotypes (Ia, Ib, II, III, IV, and V) will be determined and a serum pooling strategy developed to produce a QCS panel consisting of three samples that span high, medium and low IgG values for each serotype and a 22- member bridging panel that will span the range of the assay for all serotypes. The QC panels will be distributed to members of the GASTON consortium for the purpose of assay performance monitoring until they are depleted.
Time frame: 1 year
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