A measles and rubella vaccine microneedle patch in The Gambia: a phase 1/2, double-blind, double-dummy, randomised, active-controlled, age de-escalation trial.

BACKGROUND: Microneedle patches (MNPs) have been ranked as the highest global priority innovation for overcoming immunisation barriers in low-income and middle-income countries. This trial aimed to provide the first data on the tolerability, safety, and immunogenicity of a measles and rubella vaccine (MRV)-MNP in children. METHODS: This single-centre, phase 1/2, double-blind, double-dummy, randomised, active-controlled, age de-escalation trial was conducted in The Gambia. To be eligible, all participants had to be healthy according to prespecified criteria, aged 18-40 years for the adult cohort, 15-18 months for toddlers, or 9-10 months for infants, and to be available for visits throughout the follow-up period. The three age cohorts were randomly assigned in a 2:1 ratio (adults) or 1:1 ratio (toddlers and infants) to receive either an MRV-MNP (Micron Biomedical, Atlanta, GA, USA) and a placebo (0·9% sodium chloride) subcutaneous injection, or a placebo-MNP and an MRV subcutaneous injection (MRV-SC; Serum Institute of India, Pune, India). Unmasked staff ransomly assigned the participants using an online application, and they prepared visually identical preparations of the MRV-MNP or placebo-MNP and MRV-SC or placebo-SC, but were not involved in collecting endpoint data. Staff administering the study interventions, participants, parents, and study staff assessing trial endpoints were masked to treatment allocation. The safety population consists of all vaccinated participants, and analysis was conducted according to route of MRV administration, irrespective of subsequent protocol deviations. The immunogenicity population consisted of all vaccinated participants who had a baseline and day 42 visit result available, and who had no protocol deviations considered to substantially affect the immunogenicity endpoints. Solicited local and systemic adverse events were collected for 14 days following vaccination. Unsolicited adverse events were collected to day 180. Age de-escalation between cohorts was based on the review of the safety data to day 14 by an independent data monitoring committee. Serum neutralising antibodies to measles and rubella were measured at baseline, day 42, and day 180. Analysis was descriptive and included safety events, seroprotection and seroconversion rates, and geometric mean antibody concentrations. The trial was registered with the Pan African Clinical Trials Registry PACTR202008836432905, and is complete. FINDINGS: Recruitment took place between May 18, 2021, and May 27, 2022. 45 adults, 120 toddlers, and 120 infants were randomly allocated and vaccinated. There were no safety concerns in the first 14 days following vaccination in either adults or toddlers, and age de-escalation proceeded accordingly. In infants, 93% (52/56; 95% CI 83·0-97·2) seroconverted to measles and 100% (58/58; 93·8-100) seroconverted to rubella following MRV-MNP administration, while 90% (52/58; 79·2-95·2) and 100% (59/59; 93·9-100) seroconverted to measles and rubella respectively, following MRV-SC. Induration at the MRV-MNP application site was the most frequent local reaction occurring in 46 (77%) of 60 toddlers and 39 (65%) of 60 infants. Related unsolicited adverse events, most commonly discolouration at the application site, were reported in 35 (58%) of 60 toddlers and 57 (95%) of 60 infants that had received the MRV-MNP. All local reactions were mild. There were no related severe or serious adverse events. INTERPRETATION: The safety and immunogenicity data support the accelerated development of the MRV-MNP. FUNDING: Bill & Melinda Gates Foundation.

Immunogenicity and safety of a 10-valent pneumococcal conjugate vaccine administered as a 2 + 1 schedule to healthy infants in The Gambia: a single-centre, double-blind, active-controlled, randomised, phase 3 trial.

BACKGROUND: Three pneumococcal conjugate vaccines (PCVs) are currently licensed and WHO prequalified for supply by UN agencies. Here, we aimed to investigate the safety and immunogenicity of SIIPL-PCV compared with PHiD-CV and PCV13, when administered to infants according to a 2 + 1 schedule. METHODS: This single-centre, double-blind, active-controlled, randomised, phase 3 trial was done in Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine clinical trial facilities within two government health centres in the western region of The Gambia. Healthy, PCV-naive infants aged 6-8 weeks were enrolled if they weighed at least 3·5 kg and had no clinically significant health complaints, as determined by history and clinical examination. Eligible infants were randomly assigned (1:1:1) to receive either SIIPL-PCV, PHiD-CV, or PCV13 using permuted blocks of variable size. Parents and the trial staff assessing all study outcomes were masked to vaccine group. The first PCV vaccine was given with other routine Expanded Programme on Immunization vaccines when infants were aged 6-8 weeks (visit 1). At visit 2, routine vaccines alone (without a PCV) were administered. At visit 3, the second dose of the PCV was administered alongside other routine vaccines. At visit 4, a blood sample was collected. Visits 1-4 took place at intervals of 4 weeks. The booster PCV was administered at age 9-18 months (visit 5), with final follow-up 4 weeks after the booster (visit 6). The primary immunogenicity outcome compared the serotype-specific IgG geometric mean concentrations (GMCs) generated by SIIPL-PCV with those generated by PHiD-CV and PCV13, 4 weeks after the booster. We used descriptive 95% CIs without adjustment for multiplicity. Immunogenicity analyses were done in the per protocol population (defined as all children who received all the assigned study vaccines, who had an immunogenicity measurement available, and who had no protocol deviations that might interfere with the immunogenicity assessment). This trial was registered with the Pan African Clinical Trials Registry, PACTR201907754270299, and ClinicalTrials.gov, NCT03896477. FINDINGS: Between July 18 and Nov 14, 2019, 745 infants were assessed for study eligibility. Of these, 85 infants (11%) were ineligible and 660 (89%) were enrolled and randomly assigned to receive SIIPL-PCV (n=220), PHiD-CV (n=220), or PCV13 (n=220). 602 infants (91%) were included in the per protocol immunogenicity population. The median age at vaccination was 46 days (range 42-56). 342 infants (52%) were female and 318 (48%) were male. Post-booster serotype-specific IgG GMCs generated by SIIPL-PCV ranged from 1·54 µg/mL (95% CI 1·38-1·73) for serotype 5 to 12·46 µg/mL (11·07-14·01) for serotype 6B. Post-booster GMCs against shared serotypes generated by PHiD-CV ranged from 0·80 µg/mL (0·72-0·88) for serotype 5 to 17·31 µg/mL (14·83-20·20) for serotype 19F. Post-booster GMCs generated by PCV13 ranged from 2·04 µg/mL (1·86-2·24) for serotype 5 to 15·54 µg/mL (13·71-17·60) for serotype 6B. Post-booster IgG GMCs generated by SIIPL-PCV were higher than those generated by PHiD-CV for seven of the eight shared serotypes (1, 5, 6B, 7F, 9V, 14, and 23F). The GMC generated by serotype 19F was higher after PHiD-CV. The SIIPL-PCV to PHiD-CV GMC ratios for shared serotypes ranged from 0·64 (95% CI 0·52-0·79) for serotype 19F to 2·91 (2·47-3·44) for serotype 1. The serotype 1 GMC generated by SIIPL-PCV was higher than that generated by PCV13, whereas serotype 5, 6A, 19A, and 19F GMCs were higher after PCV13. The SIIPL-PCV to PCV13 GMC ratios ranged from 0·72 (0·60-0·87) for serotype 19A to 1·44 (1·23-1·69) for serotype 1. INTERPRETATION: SIIPL-PCV was safe and immunogenic when given to infants in The Gambia according to a 2 + 1 schedule. This PCV is expected to provide similar protection against invasive and mucosal pneumococcal disease to the protection provided by PCV13 and PHiD-CV, for which effectiveness data are available. Generating post-implementation data on the impact of SIIPL-PCV on pneumococcal disease endpoints remains important. FUNDING: Bill & Melinda Gates Foundation.

Study protocol for a phase 1/2, single-centre, double-blind, double-dummy, randomized, active-controlled, age de-escalation trial to assess the safety, tolerability and immunogenicity of a measles and rubella vaccine delivered by a microneedle patch in healthy adults (18 to 40 years), measles and rubella vaccine-primed toddlers (15 to 18 months) and measles and rubella vaccine-naïve infants (9 to 10 months) in The Gambia [Measles and Rubella Vaccine Microneedle Patch Phase 1/2 Age De-escalation Trial].

BACKGROUND: New strategies to increase measles and rubella vaccine coverage, particularly in low- and middle-income countries, are needed if elimination goals are to be achieved. With this regard, measles and rubella vaccine microneedle patches (MRV-MNP), in which the vaccine is embedded in dissolving microneedles, offer several potential advantages over subcutaneous delivery. These include ease of administration, increased thermostability, an absence of sharps waste, reduced overall costs and pain-free administration. This trial will provide the first clinical trial data on MRV-MNP use and the first clinical vaccine trial of MNP technology in children and infants. METHODS: This is a phase 1/2, randomized, active-controlled, double-blind, double-dummy, age de-escalation trial. Based on the defined eligibility criteria for the trial, including screening laboratory investigations, 45 adults [18-40 years] followed by 120 toddlers [15-18 months] and 120 infants [9-10 months] will be enrolled in series. To allow double-blinding, participants will receive either the MRV-MNP and a placebo (0.9% sodium chloride) subcutaneous (SC) injection or a placebo MNP and the MRV by SC injection (MRV-SC). Local and systemic adverse event data will be collected for 14 days following study product administration. Safety laboratories will be repeated on day 7 and, in the adult cohort alone, on day 14. Unsolicited adverse events including serious adverse events will be collected until the final study visit for each participant on day 180. Measles and rubella serum neutralizing antibodies will be measured at baseline, on day 42 and on day 180. Cohort progression will be dependent on review of the unblinded safety data by an independent data monitoring committee. DISCUSSION: This trial will provide the first clinical data on the use of a MNP to deliver the MRV and the first data on the use of MNPs in a paediatric population. It will guide future product development decisions for what may be a key technology for future measles and rubella elimination. TRIAL REGISTRATION: Pan-African Clinical Trials Registry 202008836432905 . CLINICALTRIALS: gov NCT04394689.

Intradermal administration of fractional doses of the inactivated poliovirus vaccine in a campaign: a pragmatic, open-label, non-inferiority trial in The Gambia.

BACKGROUND: A rapid increase in circulating vaccine-derived poliovirus type 2 outbreaks, and the need to reserve inactivated poliovirus vaccine (IPV) for routine immunisation, has increased the value of fractional dose IPV (fIPV) as a measure to prevent acute flaccid paralysis. However, the intradermal route of administration has been viewed as prohibitive to outbreak response campaigns. We aimed to establish the immunogenicity and safety of administering intradermal fIPV with a disposable syringe jet injector (DSJI) or an intradermal adaptor (IDA) compared with standard administration with a BCG needle and syringe (N&S). METHODS: This pragmatic, non-inferiority trial was undertaken in a campaign setting in communities in The Gambia. Children aged 4-59 months without contraindication to vaccination were eligible. Children were not individually randomly assigned; instead, the vaccination teams were randomly assigned (1:1:1) to one of three administration methods. Parents and the field team were not masked, but laboratory personnel were masked. Baseline demographic and anthropometric data were collected from the participants. Public health officers experienced at intradermal immunisation, and nurses without experience, had 2 h of training on each of the administration methods before the campaign. Participants were vaccinated using the administration method in use by the vaccination team in their community. Poliovirus serum neutralising antibodies (SNA) were measured in children aged 24-59 months before and 4 weeks after vaccination. Adverse events and data on injection quality were collected from all participants. The primary outcome was the type 2 immune response rate (seroconversion in seronegative [SNA titre <8] children plus a 4-fold titre rise in seropositive children). Adjusted differences in the immune response between the DSJI or IDA group versus the N&S group were calculated with 97·5% CIs. A margin of -10% was used to define the non-inferiority of DSJI or IDA compared to N&S. Immunogenicity analysis was done per protocol. The trial is registered with ClinicalTrials.govNCT02967783 and has been completed. FINDINGS: Between Oct 28 and Dec 29, 2016, 3189 children aged 4-59 months were recruited, of whom 3170 were eligible. Over 3 days, 2720 children were vaccinated (N&S, 917; IDA, 874; and DSJI, 929). Among 992 children aged 25-59 months with a baseline SNA available, 90·1% (95% CI 86·1-92·9; 281/312) of those vaccinated using the DSJI had an immune response to type 2 compared with 93·8% (90·6-95·8; 331/353) of those vaccinated with N&S and 96·6% (94·0-98·0; 316/327) of those vaccinated with IDA. All (53/53) type 2 seronegative children seroconverted. For polio type 2, non-inferiority was shown for both the IDA (adjusted difference 0·7% [97·5% CI -3·3 to 4·7], unadjusted difference 2·9% [-0·9 to 6·8]) and DSJI (adjusted difference -3·3% [-8·3 to 1·5], unadjusted difference -3·7% [-8·7 to 1·1]) compared with N&S. Non-inferiority was shown for type 1 and 3 for the IDA and DSJI. Neither injection quality nor the training and experience of the vaccinators had an effect on immune response. No safety concerns were reported. INTERPRETATION: In a campaign, intradermal fIPV is safe and generates consistent immune responses that are not dependent on vaccinator experience or injection quality when administered using an N&S, DSJI, or IDA. Countries facing vaccine-derived poliovirus type 2 outbreaks should consider fIPV campaigns to boost population immunity and prevent cases of acute flaccid paralysis. FUNDING: World Health Organization and the Medical Research Council.

Immunogenicity and safety of a novel ten-valent pneumococcal conjugate vaccine in healthy infants in The Gambia: a phase 3, randomised, double-blind, non-inferiority trial.

BACKGROUND: An affordable pneumococcal conjugate vaccine (PCV) is needed to ensure sustainable access in low-income and middle-income countries. This trial examined the immunogenicity and safety of a novel ten-valent PCV (SIIPL-PCV) containing serotypes 1, 5, 6A, 6B, 7F, 9V, 14, 19A, 19F, and 23F compared with the pneumococcal polysaccharide protein D-conjugate vaccine (PHiD-CV; Synflorix; GlaxoSmithKline; Brentford, UK). METHODS: In this single-centre, randomised, double-blind, phase 3, non-inferiority trial in The Gambia, healthy, PCV-naive infants aged 6-8 weeks were enrolled and assigned using permuted block randomisation to receive one of three lots of SIIPL-PCV or to PHiD-CV in a ratio of 2:2:2:3. Parents and all staff assessing study outcomes were masked to group assignment. Vaccines (0·5 mL SIIPL-PCV or 0·5 mL PHiD-CV) were administered at ages 6, 10, and 14 weeks by intramuscular injection. Primary immunogenicity outcomes, measured at age 18 weeks, were serotype-specific IgG geometric mean concentrations (GMCs) and seroresponse rates (IgG ≥ 0·35 µg/mL). Lot-to-lot equivalence (objective 1) was shown if the upper and lower bounds of the two-sided 95% CI around the GMC ratio for each pairwise lot-to-lot comparison was between the 0·5 and 2·0 equivalence margins for all ten serotypes. The immunogenicity of SIIPL-PCV was defined as being non-inferior to that of PHiD-CV (objective 2) if, for at least seven of the ten serotypes in SIIPL-PCV, the lower bound of the 97·5% CI for the GMC ratio was greater than 0·5, or the lower bound of the 97·5% CI for differences in seroresponse rate was greater than -10%. The GMC and seroresponse rates to serotypes 6A and 19A, which are not in PHiD-CV, were compared with those of the serotype in PHiD-CV that had the lowest seroresponse rate. Non-inferiority of the immune responses to antigens in the co-administered Expanded Programme on Immunization (EPI) vaccines (objective 3) was declared if the lower bound of the 95% CI for the difference between SIIPL-PCV and PHiD-CV in seroresponse rates, or GMC ratios for pertussis antigens, was greater than -10% (or 0·5 for pertussis antigens) for all vaccine antigens. Safety data were assessed according to treatment received at the first visit in infants who received at least one dose of study vaccine and for whom at least some post-vaccination safety data were available. The primary immunogenicity analysis was in the per-protocol immunogenicity population, which included infants who received all study vaccines and had immunogenicity measurements after vaccination and no major protocol deviations. This trial is registered at ClinicalTrials.gov (NCT03197376). FINDINGS: Between June 21, 2017, and Jan 29, 2018, 2250 infants were enrolled and randomly assigned to receive SIIPL-PCV (n=1503; 502 to lot 1, 501 to lot 2, and 500 to lot 3) or PHiD-CV (n=747). 1458 (97·0%) infants assigned to SIIPL-PCV and 724 (96·9%) assigned to PHiD-CV were included in the per-protocol primary immunogenicity analysis. Lot-to-lot equivalence was shown, with the lowest lower bound of the 95% CI for the GMC ratio being 0·52 (for serotype 6B in lot 2 vs lot 3) and the highest upper bound being 1·69 (for serotype 6B in lot 1 vs lot 2). SIIPL-PCV was non-inferior to PHiD-CV in terms of immunogenicity: the lower bound of the 97·5% CI for the GMC ratio was greater than 0·5 (the lowest being 0·67 for serotype 19F) and the lower bound of the 97·5% CI for the difference in seroresponse rate was greater than -10% (the lowest being -2·2% for serotype 6B) for all ten serotypes in SIIPL-PCV. The lowest seroresponse rate after PHiD-CV was to serotype 6B (76·7% [95% CI 73·4-79·7]). This serotype was therefore used for the comparisons with serotype 6A and 19A in SIIPL-PCV. Non-inferiority of immune responses to the EPI vaccines after co-administration with SIIPL-PCV compared with after co-administration with PHiD-CV was shown for all vaccine antigens included in the primary series. The lowest lower bound of the 95% CI for the difference in seroresponse rates was -7·1% for rotavirus antibody and for the GMC ratio for pertussis antigens was 0·62 for anti-pertussis toxoid. 1131 (75·2%) of 1503 infants in the SIIPL-PCV group and 572 (76·6%) of 747 in the PHiD-CV group had at least one unsolicited adverse event. 36 (2·4%) participants in the SIIPL-PCV group and 18 (2·4%) in the PHiD-CV group had a serious adverse event; none were considered related to vaccination. In infants who were selected to have solicited adverse events recorded, injection-site induration after primary vaccinations occurred in 27 (4·9%) of 751 infants who received SIIPL-PCV versus 34 (9·4%) of 364 who received PHiD-CV (p=0·0032). There were no other notable differences in the safety profiles of the two vaccines. One infant in the SIIPL-PCV group and two in the PHiD-CV group died during the study. The deaths were not considered to be related to study vaccination or study participation. INTERPRETATION: The immunogenicity of SIIPL-PCV was non-inferior to that of PHiD-CV, for which efficacy and effectiveness data against pneumococcal disease are available. The vaccine is safe and can be co-administered with routine EPI vaccines. The data generated in this trial have supported the licensure and pre-qualification of SIIPL-PCV, making the vaccine available for introduction into national immunisation programmes. Generating post-implementation data confirming vaccine impact remains important. FUNDING: Bill & Melinda Gates Foundation.

Safety and immunogenicity of a novel 10-valent pneumococcal conjugate vaccine candidate in adults, toddlers, and infants in The Gambia-Results of a phase 1/2 randomized, double-blinded, controlled trial.

BACKGROUND: A more affordable pneumococcal conjugate vaccine (PCV) that provides comparable protection to current PCVs is needed to ensure sustainable access in resource-limited settings. Serum Institute of India Pvt. Ltd.'s PCV candidate (SIIPL-PCV) has the potential to meet this need as manufacturing efficiency has been optimized and the vaccine targets the most prevalent disease-causing serotypes in Africa and Asia. We report SIIPL-PCV's safety, tolerability, and immunogenicity in adults, toddlers, and infants in The Gambia. METHODS: This phase 1/2, randomized, double-blind trial sequentially enrolled 34 PCV-naive adults (18-40 years old), 112 PCV (Prevenar 13® [PCV13])-primed toddlers (12-15 months old), and 200 PCV-naive infants (6-8 weeks old), who were randomized (1:1) to receive SIIPL-PCV or a licensed comparator vaccine. Infants received three-doses of SIIPL-PCV or PCV13 at 6, 10, and 14 weeks of age co-administered with routine Expanded Program on Immunization (EPI) vaccines. Reactogenicity was solicited through seven-days post-vaccination; unsolicited adverse events (AEs) were assessed throughout the study. The safety and immunogenicity of a matching booster at 10-14 months of age were evaluated in a subset of 96 infants. Immune responses were evaluated post-primary and pre- and post-booster vaccinations. RESULTS: Reactogenicity was primarily mild-to-moderate in severity. In infants, the most common solicited reactions were injection-site tenderness and fever, with no meaningful treatment-group differences. There were no serious or severe vaccine-related AEs and no meaningful trends in SAEs, vaccine-related AEs, or overall AEs. Infant post-primary seroresponse rates (IgG level ≥ 0.35 µg/mL) were ≥89% for all serotypes except 6A (79%) in the SIIPL-PCV group. IgG GMCs were >1 µg/mL for all serotypes in both SIIPL-PCV and PCV13 groups. Post-booster GMCs were comparable between groups. CONCLUSION: SIIPL-PCV was well-tolerated, had an acceptable safety profile, and was immunogenic for all vaccine serotypes. Results support the evaluation of SIIPL-PCV in a phase 3 non-inferiority trial. Clinicaltrials.gov: NCT02308540.

The Immunogenicity of Fractional Intradermal Doses of the Inactivated Poliovirus Vaccine Is Associated With the Size of the Intradermal Fluid Bleb.

The immunogenicity of fractional (one-fifth, 0.1 mL) intradermal doses of the inactivated poliovirus vaccine (ID fIPV) is positively correlated with the size of the intradermal fluid bleb. Training of vaccinators for campaign and routine ID fIPV administration should focus on generating an 8- to 10-mm bleb with each injection. Clinical Trials Registration NCT01847872.

Safety and immunogenicity of inactivated poliovirus vaccine when given with measles-rubella combined vaccine and yellow fever vaccine and when given via different administration routes: a phase 4, randomised, non-inferiority trial in The Gambia.

BACKGROUND: The introduction of the inactivated poliovirus vaccine (IPV) represents a crucial step in the polio eradication endgame. This trial examined the safety and immunogenicity of IPV given alongside the measles-rubella and yellow fever vaccines at 9 months and when given as a full or fractional dose using needle and syringe or disposable-syringe jet injector. METHODS: We did a phase 4, randomised, non-inferiority trial at three periurban government clinics in west Gambia. Infants aged 9-10 months who had already received oral poliovirus vaccine were randomly assigned to receive the IPV, measles-rubella, and yellow fever vaccines, singularly or in combination. Separately, IPV was given as a full intramuscular or fractional intradermal dose by needle and syringe or disposable-syringe jet injector at a second visit. The primary outcomes were seroprevalence rates for poliovirus 4-6 weeks post-vaccination and the rate of seroconversion between baseline and post-vaccination serum samples for measles, rubella, and yellow fever; and the post-vaccination antibody titres generated against each component of the vaccines. We did a per-protocol analysis with a non-inferiority margin of 10% for poliovirus seroprevalence and measles, rubella, and yellow fever seroconversion, and (1/3) log2 for log2-transformed antibody titres. This trial is registered with ClinicalTrials.gov, number NCT01847872. FINDINGS: Between July 10, 2013, and May 8, 2014, we assessed 1662 infants for eligibility, of whom 1504 were enrolled into one of seven groups for vaccine interference and one of four groups for fractional dosing and alternative route of administration. The rubella and yellow fever antibody titres were reduced by co-administration but the seroconversion rates achieved non-inferiority in both cases (rubella, -4·5% [95% CI -9·5 to -0·1]; yellow fever, 1·2% [-2·9 to 5·5]). Measles and poliovirus responses were unaffected (measles, 6·8% [95% CI -1·4 to 14·9]; poliovirus serotype 1, 1·6% [-6·7 to 4·7]; serotype 2, 0·0% [-2·1 to 2·1]; serotype 3, 0·0% [-3·8 to 3·9]). Poliovirus seroprevalence was universally high (>97%) after vaccination, but the antibody titres generated by fractional intradermal doses of IPV did not achieve non-inferiority compared with full dose. The number of infants who seroconverted or had a four-fold rise in titres was also lower by the intradermal route. There were no safety concerns. INTERPRETATION: The data support the future co-administration of IPV, measles-rubella, and yellow fever vaccines within the Expanded Programme on Immunization schedule at 9 months. The administration of single fractional intradermal doses of IPV by needle and syringe or disposable-syringe jet injector compromises the immunity generated, although it results in a high post-vaccination poliovirus seroprevalence. FUNDING: Bill & Melinda Gates Foundation.