Immune responses to gametocyte antigens in a malaria endemic population—the African falciparum context: a systematic review and meta-analysis
Background: Malaria elimination remains a priority research agenda with the need for interventions that reduce and/or block malaria transmission from humans to mosquitoes. Transmission-blocking vaccines (TBVs) are in development, most of which target the transmission stage (i.e., gametocyte) antigen...
| Main Authors: | , , , , , |
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| Format: | Journal article |
| Language: | English |
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Frontiers Media
2019
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| _version_ | 1797089952517849088 |
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| author | Muthui, MK Kamau, A Bousema, T Blagborough, AM Bejon, P Kapulu, MC |
| author_facet | Muthui, MK Kamau, A Bousema, T Blagborough, AM Bejon, P Kapulu, MC |
| author_sort | Muthui, MK |
| collection | OXFORD |
| description | Background: Malaria elimination remains a priority research agenda with the need for interventions that reduce and/or block malaria transmission from humans to mosquitoes. Transmission-blocking vaccines (TBVs) are in development, most of which target the transmission stage (i.e., gametocyte) antigens Pfs230 and Pfs48/45. For these interventions to be implemented, there is a need to understand the naturally acquired immunity to gametocytes. Several studies have measured the prevalence of immune responses to Pfs230 and Pfs48/45 in populations in malaria-endemic areas. Methods: We conducted a systematic review of studies carried out in African populations that measured the prevalence of immune responses to the gametocyte antigens Pfs230 and Pfs48/45. We assessed seroprevalence of antibody responses to the two antigens and investigated the effects of covariates such as age, transmission intensity/endemicity, season, and parasite prevalence on the prevalence of these antibody responses by meta-regression. Results: We identified 12 studies covering 23 sites for inclusion in the analysis. We found that the range of reported seroprevalence to Pfs230 and Pfs48/45 varied widely across studies, from 0 to 64% for Pfs48/45 and from 6 to 72% for Pfs230. We also found a modest association between increased age and increased seroprevalence to Pfs230: adults were associated with higher seroprevalence estimates in comparison to children (β coefficient 0.21, 95% CI: 0.05-0.38, p = 0.042). Methodological factors were the most significant contributors to heterogeneity between studies which prevented calculation of pooled prevalence estimates. Conclusions: Naturally acquired sexual stage immunity, as detected by antibodies to Pfs230 and Pfs48/45, was present in most studies analyzed. Significant between-study heterogeneity was seen, and methodological factors were a major contributor to this, and prevented further analysis of epidemiological and biological factors. This demonstrates a need for standardized protocols for conducting and reporting seroepidemiological analyses. |
| first_indexed | 2024-03-07T03:11:27Z |
| format | Journal article |
| id | oxford-uuid:b4581aa8-ae84-4e69-9403-c4429cf9e90f |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T03:11:27Z |
| publishDate | 2019 |
| publisher | Frontiers Media |
| record_format | dspace |
| spelling | oxford-uuid:b4581aa8-ae84-4e69-9403-c4429cf9e90f2022-03-27T04:25:26ZImmune responses to gametocyte antigens in a malaria endemic population—the African falciparum context: a systematic review and meta-analysisJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:b4581aa8-ae84-4e69-9403-c4429cf9e90fEnglishSymplectic Elements at OxfordFrontiers Media2019Muthui, MKKamau, ABousema, TBlagborough, AMBejon, PKapulu, MCBackground: Malaria elimination remains a priority research agenda with the need for interventions that reduce and/or block malaria transmission from humans to mosquitoes. Transmission-blocking vaccines (TBVs) are in development, most of which target the transmission stage (i.e., gametocyte) antigens Pfs230 and Pfs48/45. For these interventions to be implemented, there is a need to understand the naturally acquired immunity to gametocytes. Several studies have measured the prevalence of immune responses to Pfs230 and Pfs48/45 in populations in malaria-endemic areas. Methods: We conducted a systematic review of studies carried out in African populations that measured the prevalence of immune responses to the gametocyte antigens Pfs230 and Pfs48/45. We assessed seroprevalence of antibody responses to the two antigens and investigated the effects of covariates such as age, transmission intensity/endemicity, season, and parasite prevalence on the prevalence of these antibody responses by meta-regression. Results: We identified 12 studies covering 23 sites for inclusion in the analysis. We found that the range of reported seroprevalence to Pfs230 and Pfs48/45 varied widely across studies, from 0 to 64% for Pfs48/45 and from 6 to 72% for Pfs230. We also found a modest association between increased age and increased seroprevalence to Pfs230: adults were associated with higher seroprevalence estimates in comparison to children (β coefficient 0.21, 95% CI: 0.05-0.38, p = 0.042). Methodological factors were the most significant contributors to heterogeneity between studies which prevented calculation of pooled prevalence estimates. Conclusions: Naturally acquired sexual stage immunity, as detected by antibodies to Pfs230 and Pfs48/45, was present in most studies analyzed. Significant between-study heterogeneity was seen, and methodological factors were a major contributor to this, and prevented further analysis of epidemiological and biological factors. This demonstrates a need for standardized protocols for conducting and reporting seroepidemiological analyses. |
| spellingShingle | Muthui, MK Kamau, A Bousema, T Blagborough, AM Bejon, P Kapulu, MC Immune responses to gametocyte antigens in a malaria endemic population—the African falciparum context: a systematic review and meta-analysis |
| title | Immune responses to gametocyte antigens in a malaria endemic population—the African falciparum context: a systematic review and meta-analysis |
| title_full | Immune responses to gametocyte antigens in a malaria endemic population—the African falciparum context: a systematic review and meta-analysis |
| title_fullStr | Immune responses to gametocyte antigens in a malaria endemic population—the African falciparum context: a systematic review and meta-analysis |
| title_full_unstemmed | Immune responses to gametocyte antigens in a malaria endemic population—the African falciparum context: a systematic review and meta-analysis |
| title_short | Immune responses to gametocyte antigens in a malaria endemic population—the African falciparum context: a systematic review and meta-analysis |
| title_sort | immune responses to gametocyte antigens in a malaria endemic population the african falciparum context a systematic review and meta analysis |
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