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Molecular Biotechnology Jul 2023Emerging infectious diseases have vigorously devastated the global economy and health sector; cost-effective plant-based vaccines (PBV) can be the potential solution to... (Review)
Review
Emerging infectious diseases have vigorously devastated the global economy and health sector; cost-effective plant-based vaccines (PBV) can be the potential solution to withstand the current health economic crisis. The prominent role of tobacco as an efficient expression system for PBV has been well-established for decades, through this review we highlight the importance of tobacco-based vaccines (TBV) against evolving infectious diseases in humans. Studies focusing on the use of TBV for human infectious diseases were searched in PubMed, Google Scholar, and science direct from 1995 to 2021 using the keywords Tobacco-based vaccines OR transgenic tobacco OR Nicotiana benthamiana vaccines AND Infectious diseases or communicable diseases. We carried out a critical review of the articles and studies that fulfilled the eligibility criteria and were included in this review. Of 976 studies identified, only 63 studies fulfilling the eligibility criteria were included, which focused on either the in vitro, in vivo, or clinical studies on TBV for human infectious diseases. Around 43 in vitro studies of 23 different infectious pathogens expressed in tobacco-based systems were identified and 23 in vivo analysis studies were recognized to check the immunogenicity of vaccine candidates while only 10 of these were subjected to clinical trials. Viral infectious pathogens were studied more than bacterial pathogens. From our review, it was evident that TBV can be an effective health strategy to combat the emerging viral infectious diseases which are very difficult to manage with the current health facilities. The timely administration of cost-effective TBV can prevent the outburst of viral infections, thereby can protect the global healthcare system to a greater extent.
Topics: Humans; Nicotiana; Vaccines; Vaccines, Virus-Like Particle; Malaria Vaccines; Virus Diseases
PubMed: 36528727
DOI: 10.1007/s12033-022-00627-5 -
PloS One 2022Malaria is the second leading cause of death in children after diarrheal disease, with low- and middle-income countries (LMICs) accounting for over 9 in 10 incidence and... (Meta-Analysis)
Meta-Analysis
A systematic review and meta-analysis of the prevalence of caregiver acceptance of malaria vaccine for under-five children in low-income and middle-income countries (LMICs).
INTRODUCTION
Malaria is the second leading cause of death in children after diarrheal disease, with low- and middle-income countries (LMICs) accounting for over 9 in 10 incidence and deaths. Widespread acceptance and uptake of the RTS,S vaccine, recently approved by the world health organization (WHO), is projected to significantly reduce malaria incidence and deaths. Therefore, we conducted this systematic review and meta-analysis with the aim to determine the malaria vaccine acceptance rate and the factors associated with acceptance.
METHODS
We searched six databases including Google Scholar, PubMed, Cochrane, African Index Medicus, The Regional Office for Africa Library, and WHO Institutional Repository for Information Sharing (IRIS) to identify studies evaluating the malaria vaccine acceptance rate. This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. Studies were included if they were original articles published in the English language in peer-reviewed journals and assessed the prevalence of willingness to accept a free malaria vaccine, and not qualitative. The risk of publication bias was checked using both Beggar's funnel plot and Egger's test, while the I2 statistic was used to assess the heterogeneity of the included studies. Study quality was determined using the Newcastle-Ottawa scale. A meta-analysis was performed using a random effects model to evaluate the pooled prevalence of malaria vaccine acceptance. The protocol for this article was registered prospectively on the International Prospective Register for Systematic Reviews (PROSPERO), with ID number CRD42022334282).
RESULTS
Our analysis included 11 studies with a total sample size of 14, 666 participants. The aggregate malaria vaccine acceptance rate was 95.3% (95% CI:93.0%-97.2%). Among the general population, the acceptance rate was 96.3% (95% CI:92.0%-99.0%) and among mothers, it was 94.4% (95% CI:90.8%-97.2%). By country, Nigeria had the highest acceptance rate (97.6%, 95% CI:96.0%-98.8%), followed by Ghana (94.6%, 95% CI:93.8%-95.3%) and Tanzania (92.5%, 95% CI:84.4%-97.8%). Sociodemographic determinants of vaccine acceptance included place of residence, tribe, age, sex, occupation, and religion. Reasons for low acceptance included safety concerns, efficacy profile, vaccine's requirement for multiple injections, and poor level of awareness.
CONCLUSION
Future efforts should be focused on identifying factors that may improve the actual uptake of the RTS,S vaccine in malaria-endemic communities.
Topics: Child; Humans; Malaria Vaccines; Prevalence; Caregivers; Developing Countries; Ghana
PubMed: 36455209
DOI: 10.1371/journal.pone.0278224 -
Vaccine Oct 2020Leishmania (L.) infantum is a vector-borne parasite currently endemic in several Southern countries of European Union (EU), and dogs represent the main reservoir and... (Meta-Analysis)
Meta-Analysis Review
Leishmania (L.) infantum is a vector-borne parasite currently endemic in several Southern countries of European Union (EU), and dogs represent the main reservoir and hosts. Data from clinical trials are inconsistent with respect to the efficacy of vaccination against L. infantum infection. Therefore, a quantitative synthesis via pairwise meta-analysis was performed in agreement with the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) to increase the strength of evidence and assess the real efficacy profile of vaccines against L. infantum currently approved in EU. Data obtained from 1,394 dogs were extracted from 10 studies. The overall analysis indicated that vaccination is significantly effective in protecting against L. infantum infection (RR 0.40, 95%CI 0.23-0.72; I 70%; P < 0.01 vs. negative controls). The subset analysis performed by excluding the effect modifiers and by considering only the studies that assessed the efficacy of vaccines currently available in EU, indicated that CaniLeish® (RR 0.38, 95%CI 0.20-0.72; I 0%), but not Letifend® (RR 0.43, 95%CI 0.15-1.22; I 37%), significantly protected against L. infantum infection when compared to negative controls (P < 0.05). The number needed to treat analysis showed that 3.77 (95%CI 2.59-6.94) and 10.99 (95%CI 8.28-16.34) dogs had to be treated with CaniLeish® and Letifend®, respectively, to prevent one case of infection compared to negative controls. Vaccination is effective in protecting against the risk L. infantum infection, but further studies are needed to assess whether CaniLeish® and Letifend® are characterized by similar efficacy profile.
Topics: Animals; Antibodies, Protozoan; Dog Diseases; Dogs; European Union; Leishmania infantum; Leishmaniasis, Visceral; Vaccines
PubMed: 32883556
DOI: 10.1016/j.vaccine.2020.08.051 -
BMC Infectious Diseases Dec 2021The development of novel malaria vaccines and antimalarial drugs is limited partly by emerging challenges to conduct field trials in malaria endemic areas, including...
BACKGROUND
The development of novel malaria vaccines and antimalarial drugs is limited partly by emerging challenges to conduct field trials in malaria endemic areas, including unknown effects of existing immunity and a reported fall in malaria incidence. As a result, Controlled Human Malaria Infection (CHMI) has become an important approach for accelerated development of malarial vaccines and drugs. We conducted a systematic review of the literature to establish aggregate evidence on the reproducibility of a malaria sporozoite challenge model.
METHODS
A systematic review of research articles published between 1990 and 2018 on efficacy testing of malaria vaccines and drugs using sporozoite challenge and sporozoite infectivity studies was conducted using Pubmed, Scopus, Embase and Cochrane Library, ClinicalTrials.gov and Trialtrove. The inclusion criteria were randomized and non-randomized, controlled or open-label trials using P. falciparum or P. vivax sporozoite challenges. The data were extracted from articles using standardized data extraction forms and descriptive analysis was performed for evidence synthesis. The endpoints considered were infectivity, prepatent period, parasitemia and safety of sporozoite challenge.
RESULTS
Seventy CHMI trials conducted with a total of 2329 adult healthy volunteers were used for analysis. CHMI was induced by bites of mosquitoes infected with P. falciparum or P. vivax in 52 trials and by direct venous inoculation of P. falciparum sporozoites (PfSPZ challenge) in 18 trials. Inoculation with P. falciparum-infected mosquitoes produced 100% infectivity in 40 studies and the mean/median prepatent period assessed by thick blood smear (TBS) microscopy was ≤ 12 days in 24 studies. On the other hand, out of 12 infectivity studies conducted using PfSPZ challenge, 100% infection rate was reproduced in 9 studies with a mean or median prepatent period of 11 to 15.3 days as assessed by TBS and 6.8 to 12.6 days by PCR. The safety profile of P. falciparum and P.vivax CHMI was characterized by consistent features of malaria infection.
CONCLUSION
There is ample evidence on consistency of P. falciparum CHMI models in terms of infectivity and safety endpoints, which supports applicability of CHMI in vaccine and drug development. PfSPZ challenge appears more feasible for African trials based on current evidence of safety and efficacy.
Topics: Adult; Animals; Humans; Malaria Vaccines; Malaria, Falciparum; Pharmaceutical Preparations; Reproducibility of Results; Sporozoites
PubMed: 34930178
DOI: 10.1186/s12879-021-06953-4 -
Immunotherapy Jun 2021Current treatments for leishmaniases are not satisfactory, thus alternatives are needed. We searched for clinical trials with immunotherapeutic approaches for patients... (Meta-Analysis)
Meta-Analysis
Current treatments for leishmaniases are not satisfactory, thus alternatives are needed. We searched for clinical trials with immunotherapeutic approaches for patients with leishmaniasis. Out of 205 articles, 24 clinical trials were selected, and eight submitted to meta-analysis. A reduction in healing time was observed in patients with tegumentary leishmaniasis treated with pentavalent antimony plus granulocyte-macrophage colony-stimulating factor, and therapeutic vaccines. Overall meta-analysis indicated that immunotherapy associated with the standard chemotherapy generated a significantly reduced risk of treatment failure than the pentavalent antimony alone (p = 0.03). Our review confirmed the efficacy of immunotherapies for the treatment of cutaneous and visceral leishmaniasis and highlighted the importance of clinical trials using immunotherapies for leishmaniases.
Topics: Antiprotozoal Agents; Humans; Immunotherapy; Leishmaniasis; Leishmaniasis Vaccines
PubMed: 33853344
DOI: 10.2217/imt-2020-0184 -
Revista Da Sociedade Brasileira de... 2020Trypanosoma rangeli is a protozoan that infects several domestic and wild mammals and shows significant distribution in Latin American countries. T. rangeli infection is... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Trypanosoma rangeli is a protozoan that infects several domestic and wild mammals and shows significant distribution in Latin American countries. T. rangeli infection is similar to Chagas disease, both in diagnostic and prophylactic terms. Thus, the objective of this work was to review the diagnostic aspects and use of T. rangeli as an immunogen for Trypanosoma cruzi infection.
METHODS
For this elaboration, Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were adopted with descriptors derived from the Medical Subject Headings (MeSH) platform in the PubMed/MEDLINE and SciELO databases. The inclusion criteria were defined as original articles on "Trypanosoma rangeli" and diagnostic aspects of T. rangeli infection in humans and/or research on the possible vaccines developed using T. rangeli strains for T. cruzi infection.
RESULTS
After applying the inclusion and exclusion criteria, 18 articles were procured, of which 4 addressed research on the possible vaccines developed using T. rangeli for T. cruzi infection in vertebrates and the remaining 14 predominantly dealt with the diagnostic aspects of T. rangeli infection in humans.
CONCLUSIONS
In this study, we formulated a compilation of the essential literature on this subject, emphasizing the need for more accurate and accessible techniques for the differential diagnosis of infections caused by both protozoa, and underscored several prospects in the search for a vaccine for Chagas disease.
Topics: Animals; Humans; Trypanosoma; Trypanosoma cruzi; Trypanosoma rangeli
PubMed: 32935777
DOI: 10.1590/0037-8682-0608-2019 -
Infection Jun 2024Despite the significant burden of Plasmodium falciparum (Pf) malaria and the licensure of two vaccines for use in infants and young children that are partially effective... (Meta-Analysis)
Meta-Analysis
Protective efficacy and safety of radiation-attenuated and chemo-attenuated Plasmodium Falciparum sporozoite vaccines against controlled and natural malaria infection: a systematic review and meta-analysis of randomized controlled trials.
BACKGROUND AND OBJECTIVE
Despite the significant burden of Plasmodium falciparum (Pf) malaria and the licensure of two vaccines for use in infants and young children that are partially effective in preventing clinical malaria caused by Pf, a highly effective vaccine against Pf infection is still lacking. Live attenuated vaccines using Pf sporozoites as the immunogen (PfSPZ Vaccines) hold promise for addressing this gap. Here we review the safety and efficacy of two of the most promising PfSPZ approaches: PfSPZ Vaccine (radiation attenuated PfSPZ) and PfSPZ-CVac (chemo-attenuated PfSPZ).
METHODS
We conducted a systematic review and meta-analysis by searching PubMed, EMBASE, SCOPUS, CENTRAL, and WOS until 22nd December 2021. We included randomized controlled trials (RCTs) of these two vaccine approaches that measured protection against parasitaemia following controlled human malaria infection (CHMI) in malaria-naive and malaria-exposed adults or following exposure to naturally transmitted Pf malaria in African adults and children (primary outcome) and that also measured the incidence of solicited and unsolicited adverse events as indicators of safety and tolerability after vaccination (secondary outcome). We included randomized controlled trials (RCTs) that measured the detected parasitaemia after vaccination (primary outcome) and the incidence of various solicited and unsolicited adverse events (secondary outcome). The quality of the included RCTs using the Cochrane ROB 1 tool and the quality of evidence using the GRADE system were evaluated. We pooled dichotomous data using the risk ratio (RR) for development of parasitemia in vaccinees relative to controls as a measure of vaccine efficacy (VE), including the corresponding confidence interval (CI). This study was registered with PROSPERO (CRD42022308057).
RESULTS
We included 19 RCTs. Pooled RR favoured PfSPZ Vaccine (RR: 0.65 with 95% CI [0.53, 0.79], P = 0.0001) and PfSPZ-table (RR: 0.42 with 95% CI [0.27, 0.67], P = 0.0002) for preventing parasitaemia, relative to normal saline placebo. Pooled RR showed no difference between PfSPZ Vaccine and the control in the occurrence of any solicited adverse event (RR: 1.00 with 95% CI [0.82, 1.23], P = 0.98), any local solicited adverse events (RR: 0.73 with 95% CI [0.49, 1.08], P = 0.11), any systemic solicited adverse events (RR: 0.94 with 95% CI [0.75, 1.17], P = 0.58), and any unsolicited adverse event (RR: 0.93 with 95% CI [0.78, 1.10], P = 0.37).
CONCLUSION
PfSPZ and PfSPZ-CVacs showed comparable efficacy. Therefore, they can introduce a promising strategy for malaria prophylaxis, but more large-scale field trials are required to sustain efficacy and yield clinically applicable findings.
Topics: Humans; Malaria Vaccines; Malaria, Falciparum; Parasitemia; Plasmodium falciparum; Randomized Controlled Trials as Topic; Sporozoites; Vaccines, Attenuated
PubMed: 38319556
DOI: 10.1007/s15010-024-02174-4 -
Comparative Immunology, Microbiology... Apr 2020Toxoplasma gondii is an intracellular parasite that infects a broad range of animal species and humans. As the main surface antigen of the tachyzoite, SAG1 is involved... (Meta-Analysis)
Meta-Analysis
Toxoplasma gondii is an intracellular parasite that infects a broad range of animal species and humans. As the main surface antigen of the tachyzoite, SAG1 is involved in the process of recognition, adhesion and invasion of host cells. The aim of the current systematic review study is to clarify the latest status of studies in the literature regarding SAG1-associated recombinant proteins or SAG1-associated recombinant DNAs as potential vaccines against toxoplasmosis. Data were systematically collected from six databases including PubMed, Science Direct, Web of Science, Google Scholar, EBSCO and Scopus, up to 1st of January 2019. A total of 87 articles were eligible for inclusion criteria in the current systematic review. The most common antigens used for experimental cocktail vaccines together with SAG1 were ROP2 and SAG2. In addition, the most parasite strains used were RH and ME49. Freund's adjuvant and cholera toxin have been predominantly utilized. Furthermore, regarding the animal models, route and dose of vaccination, challenge methods, measurement of immune responses and cyst burden have been discussed in the text. Most of these experimental vaccines induce immune responses and have a high degree of protection against parasite infections, increase survival rates and duration and reduce cyst burdens. The data demonstrated that SAG1 antigen has a high potential for use as a vaccine and provided a promising approach for protecting humans and animals against toxoplasmosis.
Topics: Adjuvants, Immunologic; Animals; Antigens, Protozoan; Disease Models, Animal; Humans; Immunization; Mice; Protozoan Proteins; Protozoan Vaccines; Toxoplasma; Toxoplasmosis; Vaccines, DNA
PubMed: 31958746
DOI: 10.1016/j.cimid.2020.101414 -
The Cochrane Database of Systematic... Aug 2020On the American continent, cutaneous and mucocutaneous leishmaniasis (CL and MCL) are diseases associated with infection by several species of Leishmania parasites.... (Meta-Analysis)
Meta-Analysis
BACKGROUND
On the American continent, cutaneous and mucocutaneous leishmaniasis (CL and MCL) are diseases associated with infection by several species of Leishmania parasites. Pentavalent antimonials remain the first-choice treatment. There are alternative interventions, but reviewing their effectiveness and safety is important as availability is limited. This is an update of a Cochrane Review first published in 2009.
OBJECTIVES
To assess the effects of interventions for all immuno-competent people who have American cutaneous and mucocutaneous leishmaniasis (ACML).
SEARCH METHODS
We updated our database searches of the Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase, LILACS and CINAHL to August 2019. We searched five trials registers.
SELECTION CRITERIA
Randomised controlled trials (RCTs) assessing either single or combination treatments for ACML in immuno-competent people, diagnosed by clinical presentation and Leishmania infection confirmed by smear, culture, histology, or polymerase chain reaction on a biopsy specimen. The comparators were either no treatment, placebo only, or another active compound.
DATA COLLECTION AND ANALYSIS
We used standard methodological procedures expected by Cochrane. Our key outcomes were the percentage of participants 'cured' at least three months after the end of treatment, adverse effects, and recurrence. We used GRADE to assess evidence certainty for each outcome.
MAIN RESULTS
We included 75 studies (37 were new), totalling 6533 randomised participants with ATL. The studies were mainly conducted in Central and South America at regional hospitals, local healthcare clinics, and research centres. More male participants were included (mean age: roughly 28.9 years (SD: 7.0)). The most common confirmed species were L. braziliensis, L. panamensis, and L. mexicana. The most assessed interventions and comparators were non-antimonial systemics (particularly oral miltefosine) and antimonials (particularly meglumine antimoniate (MA), which was also a common intervention), respectively. Three studies included moderate-to-severe cases of mucosal leishmaniasis but none included cases with diffuse cutaneous or disseminated CL, considered the severe cutaneous form. Lesions were mainly ulcerative and located in the extremities and limbs. The follow-up (FU) period ranged from 28 days to 7 years. All studies had high or unclear risk of bias in at least one domain (especially performance bias). None of the studies reported the degree of functional or aesthetic impairment, scarring, or quality of life. Compared to placebo, at one-year FU, intramuscular (IM) MA given for 20 days to treat L. braziliensis and L. panamensis infections in ACML may increase the likelihood of complete cure (risk ratio (RR) 4.23, 95% confidence interval (CI) 0.84 to 21.38; 2 RCTs, 157 participants; moderate-certainty evidence), but may also make little to no difference, since the 95% CI includes the possibility of both increased and reduced healing (cure rates), and IMMA probably increases severe adverse effects such as myalgias and arthralgias (RR 1.51, 95% CI 1.17 to 1.96; 1 RCT, 134 participants; moderate-certainty evidence). IMMA may make little to no difference to the recurrence risk, but the 95% CI includes the possibility of both increased and reduced risk (RR 1.79, 95% CI 0.17 to 19.26; 1 RCT, 127 participants; low-certainty evidence). Compared to placebo, at six-month FU, oral miltefosine given for 28 days to treat L. mexicana, L. panamensis and L. braziliensis infections in American cutaneous leishmaniasis (ACL) probably improves the likelihood of complete cure (RR 2.25, 95% CI 1.42 to 3.38), and probably increases nausea rates (RR 3.96, 95% CI 1.49 to 10.48) and vomiting (RR 6.92, 95% CI 2.68 to 17.86) (moderate-certainty evidence). Oral miltefosine may make little to no difference to the recurrence risk (RR 2.97, 95% CI 0.37 to 23.89; low-certainty evidence), but the 95% CI includes the possibility of both increased and reduced risk (all based on 1 RCT, 133 participants). Compared to IMMA, at 6 to 12 months FU, oral miltefosine given for 28 days to treat L. braziliensis, L. panamensis, L. guyanensis and L. amazonensis infections in ACML may make little to no difference to the likelihood of complete cure (RR 1.05, 95% CI 0.90 to 1.23; 7 RCTs, 676 participants; low-certainty evidence). Based on moderate-certainty evidence (3 RCTs, 464 participants), miltefosine probably increases nausea rates (RR 2.45, 95% CI 1.72 to 3.49) and vomiting (RR 4.76, 95% CI 1.82 to 12.46) compared to IMMA. Recurrence risk was not reported. For the rest of the key comparisons, recurrence risk was not reported, and risk of adverse events could not be estimated. Compared to IMMA, at 6 to 12 months FU, oral azithromycin given for 20 to 28 days to treat L. braziliensis infections in ACML probably reduces the likelihood of complete cure (RR 0.51, 95% CI 0.34 to 0.76; 2 RCTs, 93 participants; moderate-certainty evidence). Compared to intravenous MA (IVMA) and placebo, at 12 month FU, adding topical imiquimod to IVMA, given for 20 days to treat L. braziliensis, L. guyanensis and L. peruviana infections in ACL probably makes little to no difference to the likelihood of complete cure (RR 1.30, 95% CI 0.95 to 1.80; 1 RCT, 80 participants; moderate-certainty evidence). Compared to MA, at 6 months FU, one session of local thermotherapy to treat L. panamensis and L. braziliensis infections in ACL reduces the likelihood of complete cure (RR 0.80, 95% CI 0.68 to 0.95; 1 RCT, 292 participants; high-certainty evidence). Compared to IMMA and placebo, at 26 weeks FU, adding oral pentoxifylline to IMMA to treat CL (species not stated) probably makes little to no difference to the likelihood of complete cure (RR 0.86, 95% CI 0.63 to 1.18; 1 RCT, 70 participants; moderate-certainty evidence).
AUTHORS' CONCLUSIONS
Evidence certainty was mostly moderate or low, due to methodological shortcomings, which precluded conclusive results. Overall, both IMMA and oral miltefosine probably result in an increase in cure rates, and nausea and vomiting are probably more common with miltefosine than with IMMA. Future trials should investigate interventions for mucosal leishmaniasis and evaluate recurrence rates of cutaneous leishmaniasis and its progression to mucosal disease.
Topics: Administration, Oral; Adult; Antiprotozoal Agents; Azithromycin; BCG Vaccine; Female; Humans; Hyperthermia, Induced; Immunocompetence; Injections, Intramuscular; Injections, Intravenous; Interferon-gamma; Leishmaniasis Vaccines; Leishmaniasis, Cutaneous; Leishmaniasis, Mucocutaneous; Male; Meglumine Antimoniate; Pentoxifylline; Phosphorylcholine; Randomized Controlled Trials as Topic
PubMed: 32853410
DOI: 10.1002/14651858.CD004834.pub3 -
Frontiers in Immunology 2019Malaria elimination remains a priority research agenda with the need for interventions that reduce and/or block malaria transmission from humans to mosquitoes.... (Meta-Analysis)
Meta-Analysis
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. 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. 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, = 0.042). Methodological factors were the most significant contributors to heterogeneity between studies which prevented calculation of pooled prevalence estimates. 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.
Topics: Africa; Antibodies, Protozoan; Antigens, Protozoan; Female; Humans; Life Cycle Stages; Malaria Vaccines; Malaria, Falciparum; Male; Plasmodium falciparum
PubMed: 31695697
DOI: 10.3389/fimmu.2019.02480