Safety and immunogenicity of a parenteral trivalent P2-VP8 subunit rotavirus vaccine: a multisite, randomised, double-blind, placebo-controlled trial.

BACKGROUND: A monovalent, parenteral, subunit rotavirus vaccine was well tolerated and immunogenic in adults in the USA and in toddlers and infants in South Africa, but elicited poor responses against heterotypic rotavirus strains. We aimed to evaluate safety and immunogenicity of a trivalent vaccine formulation (P2-VP8-P[4],[6],[8]). METHODS: A double-blind, randomised, placebo-controlled, dose-escalation, phase 1/2 study was done at three South African research sites. Healthy adults (aged 18-45 years), toddlers (aged 2-3 years), and infants (aged 6-8 weeks, ≥37 weeks' gestation, and without previous receipt of rotavirus vaccination), all without HIV infection, were eligible for enrolment. In the dose-escalation phase, adults and toddlers were randomly assigned in blocks (block size of five) to receive 30 µg or 90 µg of vaccine, or placebo, and infants were randomly assigned in blocks (block size of four) to receive 15 µg, 30 µg, or 90 µg of vaccine, or placebo. In the expanded phase, infants were randomly assigned in a 1:1:1:1 ratio to receive 15 µg, 30 µg, or 90 µg of vaccine, or placebo, in block sizes of four. Participants, parents of participants, and clinical, data, and laboratory staff were masked to treatment assignment. Adults received an intramuscular injection of vaccine or placebo in the deltoid muscle on the day of randomisation (day 0), day 28, and day 56; toddlers received a single injection of vaccine or placebo in the anterolateral thigh on day 0. Infants in both phases received an injection of vaccine or placebo in the anterolateral thigh on days 0, 28, and 56, at approximately 6, 10, and 14 weeks of age. Primary safety endpoints were local and systemic reactions (grade 2 or worse) within 7 days and adverse events and serious adverse events within 28 days after each injection in all participants who received at least one injection. Primary immunogenicity endpoints were analysed in infants in either phase who received all planned injections, had blood samples analysed at the relevant timepoints, and presented no major protocol violations considered to have an effect on the immunogenicity results of the study, and included serum anti-P2-VP8 IgA, IgG, and neutralising antibody geometric mean titres and responses measured 4 weeks after the final injection in vaccine compared with placebo groups. This trial is registered with ClinicalTrials.gov, NCT02646891. FINDINGS: Between Feb 15, 2016, and Dec 22, 2017, 30 adults (12 each in the 30 µg and 90 µg groups and six in the placebo group), 30 toddlers (12 each in the 30 µg and 90 µg groups and six in the placebo group), and 557 infants (139 in the 15 µg group, 140 in the 30 µg group, 139 in the 90 µg group, and 139 in the placebo group) were randomly assigned, received at least one dose, and were assessed for safety. There were no significant differences in local or systemic adverse events, or unsolicited adverse events, between vaccine and placebo groups. There were no serious adverse events within 28 days of injection in adults, whereas one serious adverse event occurred in a toddler (febrile convulsion in the 30 µg group) and 23 serious adverse events (four in placebo, ten in 15 µg, four in 30 µg, and five in 90 µg groups) occurred among 20 infants, most commonly respiratory tract infections. One death occurred in an infant within 28 days of injection due to pneumococcal meningitis. In 528 infants (130 in placebo, 132 in 15 µg, 132 in 30 µg, and 134 in 90 µg groups), adjusted anti-P2-VP8 IgG seroresponses (≥4-fold increase from baseline) to P[4], P[6], and P[8] antigens were significantly higher in the 15 µg, 30 µg, and 90 µg groups (99-100%) than in the placebo group (10-29%; p<0·0001). Although significantly higher than in placebo recipients (9-10%), anti-P2-VP8 IgA seroresponses (≥4-fold increase from baseline) to each individual antigen were modest (20-34%) across the 15 µg, 30 µg, and 90 µg groups. Adjusted neutralising antibody seroresponses in infants (≥2·7-fold increase from baseline) to DS-1 (P[4]), 1076 (P[6]), and Wa (P[8]) were higher in vaccine recipients than in placebo recipients: p<0·0001 for all comparisons. INTERPRETATION: The trivalent P2-VP8 vaccine was well tolerated, with promising anti-P2-VP8 IgG and neutralising antibody responses across the three vaccine P types. Our findings support advancing the vaccine to efficacy testing. FUNDING: Bill & Melinda Gates Foundation.

Safety and immunogenicity of inactivated monovalent influenza A/H1N1 vaccine candidate manufactured in Vietnam.

We tested a new A/H1N1 inactivated influenza vaccine (IIV) manufactured by Institute of Vaccines and Medical Biologics (IVAC), Vietnam in 48 adults in a Phase 1, double-blinded, randomized, placebo-controlled trial. Two doses of unadjuvanted vaccine or placebo were administered three weeks apart. The vaccine was well tolerated with only transient mild local reactions and low-grade fever in a small proportion of the subjects. One serious adverse event considered unrelated to the study product was reported. The IVAC vaccine proved to be highly immunogenic with 91 percent (95% CI: 0.78, 1) of the subjects developing a ≥4 fold immune responses by hemagglutination inhibition (HAI) assay, and 96 percent (95% CI: 0.78, 1) by the microneutralization (MN) assay. Post-vaccination geometric mean titers (GMTs) were 283.7 (95% CI: 161.7, 497.5) in the HAI and 725.7 (95% CI: 411.3, 1280.3) in the MN assay. These promising results merit further development of the vaccine. ClinicalTrials.gov number: NCT01507779.

A randomized Phase III clinical trial to assess the efficacy of a bovine-human reassortant pentavalent rotavirus vaccine in Indian infants.

Rotavirus is the most common cause of moderate-to-severe infant diarrhoea in developing countries, resulting in enormous morbidity, mortality, and economic burden. A bovine-human reassortant pentavalent rotavirus vaccine (BRV-PV) targeting the globally most common strains was developed in India and tested in a randomized, double-blind, placebo-controlled end-point driven Phase III efficacy clinical trial implemented at six sites across India. Infants 6 to 8weeks of age were randomized (1:1) to receive three oral doses of BRV-PV or placebo at 6, 10, and 14weeks of age along with routine vaccines. Home visit surveillance was conducted to detect severe rotavirus gastroenteritis (SRVGE) and safety outcomes until the children reached two years of age. A total of 3749 infants received BRV-PV while 3751 received placebo. At the time of the primary end-point (when the minimum number of cases needed for analysis were accrued) the vaccine efficacy against SRVGE was 36% (95% CI 11.7, 53.6, p=0.0067) in the per protocol (PP) analysis, and 41.9% (95% CI 21.1, 57.3, p=0.0005) in the intent to treat (ITT) analysis. Vaccine efficacy over the entire follow-up period (until children reached two years of age) was 39.5% (95% CI 26.7, 50, p<0.0001) in the PP analysis and 38.8% (95% CI, 26.4, 49, p<0.0001) in the ITT analysis. Vaccine efficacy against the very severe rotavirus cases (VSRVGE, Vesikari score≥16) was 60.5% (95% CI 17.7, 81, p=0.0131) at the time of the primary analysis and 54.7% (95% CI 29.7, 70.8, p=0.0004) for the complete follow-period in the PP population. The incidence of solicited, unsolicited, and serious adverse events were similar in both the vaccine and placebo groups. Likewise, the number of intussusceptions and deaths were similar between both groups. Thus, BRV-PV is an effective, well tolerated and safe vaccine in Indian infants. (Trial registration: Clinical Trials.Gov [NCT 02133690] and Clinical Trial Registry of India [CTRI/2013/05/003667]).

Safety and immunogenicity of a parenteral P2-VP8-P[8] subunit rotavirus vaccine in toddlers and infants in South Africa: a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Efficacy of live oral rotavirus vaccines is reduced in low-income compared with high-income settings. Parenteral non-replicating rotavirus vaccines might offer benefits over oral vaccines. We assessed the safety and immunogenicity of the P2-VP8-P[8] subunit rotavirus vaccine at different doses in South African toddlers and infants. METHODS: This double-blind, randomised, placebo-controlled, dose-escalation trial was done at a single research unit based at a hospital in South Africa in healthy HIV-uninfected toddlers (aged 2 to <3 years) and term infants (aged 6 to <8 weeks, without previous rotavirus vaccination). Block randomisation (computer-generated, electronic allocation) was used to assign eligible toddlers (in a 6:1 ratio) and infants (in a 3:1 ratio) in each dose cohort (10 µg, followed by 30 µg, then 60 µg if doses tolerated) to parenteral P2-VP8-P[8] subunit rotavirus or placebo injection. The two highest tolerated doses were then assessed in an expanded cohort (in a 1:1:1 ratio). Parents of participants and clinical, data, and laboratory staff were masked to treatment assignment. P2-VP8-P[8] vaccine versus placebo was assessed first in toddlers (single injection) and then in infants (three injections 4 weeks apart). The primary safety endpoints were local and systemic reactions within 7 days after each injection, adverse events within 28 days after each injection, and all serious adverse events, assessed in toddlers and infants who received at least one dose. In infants receiving all study injections, primary immunogenicity endpoints were anti-P2-VP8-P[8] IgA and IgG and neutralising antibody seroresponses and geometric mean titres 4 weeks after the third injection. This trial is registered at ClinicalTrials.gov, number NCT02109484. FINDINGS: Between March 17, 2014, and Sept 29, 2014, 42 toddlers (36 to vaccine and six to placebo) and 48 infants (36 to vaccine and 12 to placebo) were enrolled in the dose-escalation phase, in which the 30 µg and 60 µg doses where found to be the highest tolerated doses. A further 114 infants were enrolled in the expanded cohort between Nov 3, 2014, and March 20, 2015, and all 162 infants (12 assigned to 10 µg, 50 to 30 µg, 50 to 60 µg, and 50 to placebo) were included in the safety analysis. Serum IgA seroresponses were observed in 38 (81%, 95% CI 67-91) of 47 infants in the 30 µg group and 32 (68%, 53-81) of 47 in the 60 µg group, compared with nine (20%, 10-35) of 45 in the placebo group; adjusted IgG seroresponses were seen in 46 (98%, 89-100) of 47 infants in the 30 µg group and 47 (100%; 92-100) of 47 in the 60 µg group, compared with four (9%, 2·5-21) of 45 in the placebo group; and adjusted neutralising antibody seroresponses against the homologous Wa-strain were seen in 40 (85%, 72-94) of 47 infants in both the 30 µg and 60 µg groups, compared with three (7%, 1·4-18) of 45 participants in the placebo group. Solicited reactions following any injection occurred with similar frequency and severity in participants receiving vaccine and those receiving placebo. Unsolicited adverse events were mostly mild and occurred at a similar frequency between groups. Eight serious adverse events (one with placebo, two with 30 µg, and five with 60 µg) occurred in seven infants within 28 days of any study injection, none of which were deemed related to study treatment. INTERPRETATION: The parenteral P2-VP8-P[8] vaccine was well tolerated and immunogenic in infants, providing a novel approach to vaccination against rotavirus disease. On the basis of these results, a phase 1/2 trial of a trivalent P2-VP8 (P[4], P[6], and P[8]) subunit vaccine is underway at three sites in South Africa. FUNDING: Bill & Melinda Gates Foundation.

Assessment of immune responses to H5N1 inactivated influenza vaccine among individuals previously primed with H5N2 live attenuated influenza vaccine.

During the past decade, a number of H5 subtype influenza vaccines have been developed and tested in clinical trials, but most of them induced poor serum antibody responses prompting the evaluation of novel vaccination approaches. One of the most promising ones is a "prime-boost" strategy, which could result in the induction of prompt and robust immune responses to a booster influenza vaccine following priming with homologous or heterologous vaccine strains. In our study we evaluated immunogenicity of an adjuvanted A(H5N1) inactivated influenza vaccine (IIV) in healthy adult subjects who received A(H5N2) live attenuated influenza vaccine (LAIV) 1.5 years earlier and compared this with a group of naïve subjects. We found that priming with A(H5N2) LAIV induced a long-lasting B-cell immunological memory against influenza A(H5N1) virus, which was brought on by more prompt and vigorous antibody production to a single dose of A(H5N1) IIV in the primed group, compared to the naïve controls. Thus, by day 28 after the first booster dose, the hemagglutination inhibition and neutralizing (MN) antibody titer rises were 17.2 and 30.8 in the primed group, compared to 2.3 and 8.0 in the control group, respectively. The majority (79%) of the primed individuals achieved seroprotective MN antibody titers at 7 days after the first dose of the IIV. All LAIV-primed volunteers had MN titers ≥ 1:40 by Day 28 after one dose of IIV, whereas only 58% subjects from the naïve control group developed similar immune responses at this time point. The second A(H5N1) IIV dose did not increase the immune response in the LAIV-primed group, whereas 2 doses of IIV were required for naïve volunteers to develop significant immune responses. These findings were of special significance since Russian-based LAIV technology has been licensed to WHO, through whom the vaccine has been provided to vaccine manufacturers in India, China and Thailand - countries particularly vulnerable to a pandemic influenza. The results of our study will be useful to inform the development of vaccination strategies in these countries in the event of a pandemic.

H2N2 live attenuated influenza vaccine is safe and immunogenic for healthy adult volunteers.

H2N2 influenza viruses have not circulated in the human population since 1968, but they are still being regularly detected in the animal reservoir, suggesting their high pandemic potential. To prepare for a possible H2N2 pandemic, a number of H2N2 vaccine candidates have been generated and tested in preclinical and clinical studies. Here we describe the results of a randomized, double-blind placebo-controlled phase 1 clinical trial of an H2N2 live attenuated influenza vaccine (LAIV) candidate prepared from a human influenza virus isolated in 1966. The vaccine candidate was safe and well-tolerated by healthy adults, and did not cause serious adverse events or an increased rate of moderate or severe reactogenicities. The H2N2 vaccine virus was infectious for Humans. It was shed by 78.6% and 74.1% volunteers after the first and second dose, respectively, most probably due to the human origin of the virus. Importantly, no vaccine virus transmission to unvaccinated subjects was detected during the study. We employed multiple immunological tests to ensure the adequate assessment of the H2N2 pandemic LAIV candidate and demonstrated that the majority (92.6%) of the vaccinated subjects responded to the H2N2 LAIV in one or more immunological tests, including 85.2% of subjects with antibody responses and 55.6% volunteers with cell-mediated immune responses. In addition, we observed strong correlation between the H2N2 LAIV virus replication in the upper respiratory tract and the development of antibody responses.

Lot-to-lot consistency of live attenuated SA 14-14-2 Japanese encephalitis vaccine manufactured in a good manufacturing practice facility and non-inferiority with respect to an earlier product.

We conducted a four-arm, double-blind, randomized controlled trial among 818 Bangladeshi infants between 10 and 12 months of age to establish equivalence among three lots of live attenuated SA 14-14-2 JE vaccine manufactured by the China National Biotec Group's Chengdu Institute of Biological Products (CDIBP) in a new Good Manufacturing Practice (GMP) facility and to evaluate non-inferiority of the product with a lot of the same vaccine manufactured in CDIBP's original facility. The study took place in two sites in Bangladesh, rural Matlab and Mirpur in urban Dhaka. We collected pre-vaccination (Day 0) and post-vaccination Day 28 (-4 to +14 days) blood samples to assess neutralizing anti-JE virus antibody titers in serum by plaque reduction neutralization tests (PRNT). Seroprotection following vaccination was defined as a PRNT titer ≥1:10 at Day 28 in participants non-immune at baseline. Follow-up for reactogenicity and safety was conducted through home visits at Day 7 and monitoring for serious adverse events through Day 28. Seroprotection rates ranged from 80.2% to 86.3% for all four lots of vaccine. Equivalence of the seroprotection rates between pairs of vaccine lots produced in the new GMP facility was satisfied at the pre-specified 10% margin of the 95% confidence interval (CI) for two of the three pairwise comparisons, but not for the third (-4.3% observed difference with 95% CI of -11.9 to 3.3%). Nevertheless, the aggregate seroprotection rate for all three vaccine lots manufactured in the GMP facility was calculated and found to be within the non-inferiority margin (within 10%) to the vaccine lot produced in the original facility. All four lots of vaccine were safe and well tolerated. These study results should facilitate the use of SA 14-14-2 JE vaccine as a routine component of immunization programs in Asian countries.

Screening for chromosomal abnormalities in the first trimester using ultrasound and maternal serum biochemistry in a one-stop clinic: a review of three years prospective experience.

OBJECTIVE: To evaluate the performance of a one-stop multidisciplinary clinic of screening for fetal chromosomal anomalies in the first trimester of pregnancy by a combination of maternal serum biochemistry and ultrasonography. DESIGN: Retrospective review of screening performance. SETTING: District General Hospital maternity unit. POPULATION: All women booked for routine antenatal care at Harold Wood Hospital between 1 June 1998 and 31 May 2001. The population included 12,339 women with singleton pregnancies presenting at 10-14 weeks of gestation. METHODS: Women were offered screening using a combination of maternal serum free beta-hCG and pregnancy associated plasma protein-A (PAPP-A) and fetal nuchal translucency thickness. Those with an estimated risk of >/=1 in 300 of carrying a fetus with trisomy 21 or trisomy 18 or trisomy 13 were offered the option of an invasive diagnostic test. Follow up of the outcome of all pregnancies was carried out. MAIN OUTCOME MEASURES: Uptake of screening and invasive testing, detection rate for fetal chromosomal abnormalities and false positive rate. RESULTS: The uptake of first trimester screening was 97.5% and the uptake of invasive testing in the increased risk group was 77%. The rate of detection of trisomy 21 was 92% (23 of 25), of trisomy 13 or 18 was 100% (all 15) and of all aneuploidies was 96% (49 of 51). The false positive rate was 5.2%. CONCLUSIONS: First trimester screening for trisomy 21 and other aneuploidies can be delivered in an efficient manner in a one-stop multidisciplinary clinic. The detection rates are far better than can be achieved by second trimester serum screening.