Immunogenicity and safety of a pentavalent meningococcal ABCWY vaccine in adolescents and young adults: an observer-blind, active-controlled, randomised trial

BACKGROUND

Meningococcal serogroups A, B, C, W, and Y cause nearly all meningococcal disease, and comprehensive protection requires vaccination against all five serogroups. We aimed to assess the immunogenicity and safety of a pentavalent MenABCWY vaccine comprising two licensed vaccines-meningococcal serogroup B-factor H binding protein vaccine (MenB-FHbp) and a quadrivalent meningococcal serogroup ACWY tetanus toxoid conjugate vaccine (MenACWY-TT)-compared with two doses of MenB-FHbp and a single dose of quadrivalent meningococcal serogroup ACWY CRM197-conjugate vaccine (MenACWY-CRM) as the active control. We previously reported the primary safety and immunogenicity data relating to the two-dose MenB-FHbp schedule. Here we report secondary outcomes and ad-hoc analyses relating to MenABCWY immunogenicity and safety.

METHODS

We did an observer-blind, active-controlled trial at 68 sites in the USA, Czech Republic, Finland, and Poland. Healthy individuals (aged 10-25 years) who had or had not previously received a MenACWY vaccine were randomly assigned (1:2) using an interactive voice or web-based response system, stratified by previous receipt of a MenACWY vaccine, to receive 0·5 mL of MenABCWY (months 0 and 6) and placebo (month 0) or MenB-FHbp (months 0 and 6) and MenACWY-CRM (month 0) via intramuscular injection into the upper deltoid. All individuals were masked to group allocation, except staff involved in vaccine dispensation, preparation, and administration; and protocol adherence. Endpoints for serogroups A, C, W, and Y included the proportion of participants who achieved at least a four-fold increase in serum bactericidal antibody using human complement (hSBA) titres between baseline and 1 month after each vaccination. For serogroup B, secondary endpoints included the proportion of participants who achieved at least a four-fold increase in hSBA titres from baseline for each of four primary test strains and the proportion of participants who achieved titres of at least the lower limit of quantitation against all four test strains combined at 1 month after the second dose. Endpoints for serogroups A, C, W, and Y were assessed in the modified intent-to-treat (mITT) population, which included all randomly assigned participants who received at least one vaccine dose and had at least one valid and determinate MenB or serogroup A, C, W, or Y assay result before vaccination up to 1 month after the second dose, assessed in ACWY-experienced and ACWY-naive participants separately. Secondary endpoints for serogroup B were analysed in the evaluable immunogenicity population, which included all participants in the mITT population who were randomly assigned to the group of interest, received all investigational products as randomly assigned, had blood drawn for assay testing within the required time frames, had at least one valid and determinate MenB assay result after the second vaccination, and had no important protocol deviations; outcomes were assessed in both ACWY-experienced and ACWY-naive populations combined. Non-inferiority of MenABCWY to MenACWY-CRM and MenB-FHbp was determined using a -10% non-inferiority margin for these endpoints. Reactogenicity and adverse events were assessed among all participants who received at least one vaccine dose and who had available safety data. This trial is registered with Clinicaltrials.gov, NCT03135834, and is complete.

FINDINGS

Between April 24 and November 10, 2017, 1610 participants (809 MenACWY-naive; 801 MenACWY-experienced) were randomly assigned: 544 to receive MenABCWY and placebo (n=272 MenACWY-naive; n=272 MenACWY-experienced) and 1066 to receive MenB-FHbp and MenACWY-CRM (n=537 MenACWY-naive; n=529 MenACWY-experienced). Among MenACWY-naive or MenACWY-experienced MenABCWY recipients, 75·5% (95% CI 69·8-80·6; 194 of 257; serogroup C) to 96·9% (94·1-98·7; 254 of 262; serogroup A) and 93·0% (88·4-96·2; 174 of 187; serogroup Y) to 97·4% (94·4-99·0; 224 of 230; serogroup W) achieved at least four-fold increases in hSBA titres against serogroups ACWY after dose 1 or 2, respectively, in ad-hoc analyses. Additionally, 75·8% (71·5-79·8; 320 of 422) to 94·7% (92·1-96·7; 396 of 418) of MenABCWY and 67·4% (64·1-70·6; 563 of 835) to 95·0% (93·3-96·4; 782 of 823) of MenB-FHbp recipients achieved at least four-fold increases in hSBA titres against MenB strains after dose 2 in secondary analyses; 79·9% (334 of 418; 75·7-83·6) and 74·3% (71·2-77·3; 605 of 814), respectively, achieved composite responses. MenABCWY was non-inferior to MenACWY-CRM (single dose) and to MenB-FHbp in ad-hoc analyses based on the proportion of participants with at least a four-fold increase in hSBA titres from baseline and (for MenB-FHbp only) composite responses. Reactogenicity events after vaccination were similarly frequent across groups, were mostly mild or moderate, and were unaffected by MenACWY experience. No adverse events causing withdrawals were related to the investigational product. Serious adverse events were reported in four (1·5%; 0·4-3·7) MenACWY-naive individuals in the MenABCWY group versus six (2·2%; 0·8-4·8) among MenACWY-experienced individuals in the MenABCWY group and 14 (1·3%; 0·7-2·2) in the active control group (MenACWY-experienced and MenACWY-naive individuals combined); none of these were considered related to the investigational product.

INTERPRETATION

MenABCWY immune responses were robust and non-inferior to MenACWY-CRM and MenB-FHbp administered separately, and MenABCWY was well tolerated. The favourable benefit-risk profile supports further MenABCWY evaluation as a simplified schedule compared with current adolescent meningococcal vaccination programmes.

FUNDING

Pfizer.

Potential for Maternally Administered Vaccine for Infant Group B Streptococcus

BACKGROUND

Natural history studies have correlated serotype-specific anti-capsular polysaccharide (CPS) IgG in newborns with a reduced risk of group B streptococcal disease. A hexavalent CPS-cross-reactive material 197 glycoconjugate vaccine (GBS6) is being developed as a maternal vaccine to prevent invasive group B streptococcus in young infants.

METHODS

In an ongoing phase 2, placebo-controlled trial involving pregnant women, we assessed the safety and immunogenicity of a single dose of various GBS6 formulations and analyzed maternally transferred anti-CPS antibodies. In a parallel seroepidemiologic study that was conducted in the same population, we assessed serotype-specific anti-CPS IgG concentrations that were associated with a reduced risk of invasive disease among newborns through 89 days of age to define putative protective thresholds.

RESULTS

Naturally acquired anti-CPS IgG concentrations were associated with a reduced risk of disease among infants in the seroepidemiologic study. IgG thresholds that were determined to be associated with 75 to 95% reductions in the risk of disease were 0.184 to 0.827 μg per milliliter. No GBS6-associated safety signals were observed among the mothers or infants. The incidence of adverse events and of serious adverse events were similar across the trial groups for both mothers and infants; more local reactions were observed in the groups that received GBS6 containing aluminum phosphate. Among the infants, the most common serious adverse events were minor congenital anomalies (umbilical hernia and congenital dermal melanocytosis). GBS6 induced maternal antibody responses to all serotypes, with maternal-to-infant antibody ratios of approximately 0.4 to 1.3, depending on the dose. The percentage of infants with anti-CPS IgG concentrations above 0.184 μg per milliliter varied according to serotype and formulation, with 57 to 97% of the infants having a seroresponse to the most immunogenic formulation.

CONCLUSIONS

GBS6 elicited anti-CPS antibodies against group B streptococcus in pregnant women that were transferred to infants at levels associated with a reduced risk of invasive group B streptococcal disease. (Funded by Pfizer and the Bill and Melinda Gates Foundation; C1091002 ClinicalTrials.gov number, NCT03765073.).

A phase 3, randomized, controlled, open-label study to evaluate the persistence up to 5 years of 1 or 2 doses of meningococcal conjugate vaccine MenACWY-TT given with or without 13-valent pneumococcal conjugate vaccine in 12-14-month-old children

BACKGROUND

Immunogenicity and safety up to 5 years after administration of 1 or 2 doses of quadrivalent meningococcal serogroup A, C, W, and Y tetanus toxoid conjugate vaccine (MenACWY-TT) given alone or with 13-valent pneumococcal conjugate vaccine (PCV13) in children was investigated.

METHODS

This phase 3 study randomized healthy 12-24-month-olds to MenACWY-TT at Month 0 (ACWY1d), MenACWY-TT at Months 0 and 2 (ACWY2d), MenACWY-TT and PCV13 at Month 0 (Co-Ad), or PCV13 at Month 0 and MenACWY-TT at Month 2 (PCV13/ACWY). Immune responses 1, 3, and 5 years after primary vaccination were evaluated with serum bactericidal activity using rabbit complement (rSBA) titers ≥ 1:8 and geometric mean titers (GMTs). Evaluation of serious adverse events up to 5 years after primary vaccination are reported.

RESULTS

Of the 802 children randomized in the study, 619 completed the study through Year 5. Immune responses after vaccination declined over time but were higher 5 years after vaccination compared with levels before vaccination. At Year 5, the percentages of children with rSBA titers ≥ 1:8 across all serogroups were 20.5 %-58.6 %, 28.4 %-65.8 %, 23.9 %-52.8 %, and 19.4 %-55.8 % in the ACWY1d, ACWY2d, Co-Ad, and PCV13/ACWY groups, respectively. Comparable antibody persistence at Year 5 was observed for participants receiving 1 or 2 doses of MenACWY-TT, although GMTs were elevated in those who received 2 versus 1 dose. The percentage of children with protective antibody titers at Year 5 was similar in participants who received PCV13 and MenACWY-TT compared with that observed for participants who only received 1 or 2 MenACWY-TT doses. No new safety concerns were identified during the study period.

CONCLUSION

Antibody responses persisted in the majority of children up to 5 years after primary vaccination with MenACWY-TT administered in a 1- or 2-dose regimen with or without PCV13, with no new safety concerns identified.

CLINICALTRIALS

gov Identifier NCT01939158; EudraCT number 2013-001083-28.

Plain language summary of Pfizer-BioNTech BNT162b2 vaccine protection against COVID-19 and its safety in participants 12- to 15-years-old

What is this summary about?

This is a summary of an article about part of a clinical study for the BNT162b2 COVID-19 vaccine, also called the Pfizer-BioNTech vaccine. The article was published in the New England Journal of Medicine in May 2021. This summary describes how the vaccine worked in participants 12- to 15-years old. The part of the study described in the article is ongoing and expected to finish March 2023. This means that the final results may be different from the results included in this summary.

What happened in this study?

The part of the study described in this summary included participants 12- to 15-years old who had no serious health issues. The BNT162b2 vaccine had already been studied in participants 16 years of age or older. In this part of the study, the researchers wanted to find out: How effective and safe the vaccine was in participants 12- to 15-years old. What the immune response to the vaccine and the vaccine safety were like in 12- to 15-year-olds compared with 16- to 25-year-olds. How well the vaccine prevented SARS-CoV-2 infections in participants who received the vaccine compared to those who did not. This is also called efficacy of the BNT162b2 vaccine Half of the participants in this study received 2 injections of the BNT162b2 vaccine and half received 2 injections of a placebo in a muscle of the upper arm. The placebo looked like the BNT162b2 vaccine but did not have any active vaccine in it.

What were the results?

BNT162b2 had a favorable safety profile. The most common reactions were pain at the injection site, fatigue, and headache. None of the participants had serious reactions to the vaccine. The 12- to 15-year-old participants' immune system responses to the BNT162b2 vaccine were as good as or stronger than the 16- to 25-year-old participants' immune responses. The participants who received the BNT162b2 vaccine were less likely to get COVID-19 compared with the participants who got the placebo. Clinical Trial Registration: NCT04368728 ( ClinicalTrials.gov )

Safety and immunogenicity of a primary series and booster dose of the meningococcal serogroup B-factor H binding protein vaccine (MenB-FHbp) in healthy children aged 1-9 years: two phase 2 randomised, controlled, observer-blinded studies

BACKGROUND

The meningococcal serogroup B-factor H binding protein vaccine (MenB-FHbp) is licensed for use in children aged 10 years or older for protection against invasive serogroup B meningococcal disease. Because young children are at increased risk of invasive meningococcal disease, MenB-FHbp clinical data in this population are needed.

METHODS

We conducted two phase 2 randomised, controlled, observer-blinded studies including healthy toddlers (age 12-23 months) across 26 Australian, Czech, Finnish, and Polish centres, and older children (age 2-9 years) across 14 Finnish and Polish centres. Exclusion criteria included previous vaccinations against serogroup B meningococcus or hepatitis A virus (HAV), and chronic antibiotic use. Toddlers were randomly allocated (2:1) via an interactive response technology system to receive either 60 μg or 120 μg MenB-FHbp or HAV vaccine and saline (control). Older children were randomly allocated (3:1) to receive 120 μg MenB-FHbp or control, with stratification by age group (2-3 years and 4-9 years). All vaccinations were administered as three doses (0, 2, and 6 months, with only saline given at 2 months in the control group). Toddlers who received 120 μg MenB-FHbp could receive a 120 μg booster dose 24 months after the end of the primary series. The percentages of participants with serum bactericidal activity using human complement (hSBA) titres at or above the lower limit of quantification (LLOQ; all greater than the 1:4 correlate of protection) against four test strains of serogroup B meningococcus 1 month after the third dose (primary immunogenicity endpoint) were measured in the evaluable immunogenicity populations (participants who received the vaccine as randomised, had available and determinate hSBA results, and had no major protocol violations). Not all participants were tested against all strains because of serum sample volume constraints. The frequencies of reactogenicity and adverse events after each dose were recorded in the safety population (all participants who received at least one dose and had safety data available). These studies are registered with ClinicalTrials.gov (NCT02534935 and NCT02531698) and are completed.

FINDINGS

Between Aug 31, 2015, and Aug 22, 2016, for the toddler study and between Aug 27, 2015, and March 7, 2016, for the older children study, we enrolled and randomly allocated 396 toddlers (60 μg MenB-FHbp group n=44; 120 μg MenB-FHbp group n=220; control group n=132) and 400 older children (120 μg MenB-FHbp group n=294; control group n=106). 1 month after the third dose, the proportions of participants with hSBA titres at or above the LLOQ ranged across test strains from 85·0% (95% CI 62·1-96·8; 17 of 20 participants) to 100·0% (82·4-100·0; 19 of 19) in toddlers receiving 60 μg MenB-FHbp, and from 71·6% (61·4-80·4; 68 of 95) to 100·0% (96·2-100·0; 95 of 95) in toddlers receiving 120 μg MenB-FHbp, and from 79·1% (71·2-85·6; 106 of 134) to 100·0% (97·4-100·0; 139 of 139) in children aged 2-9 years receiving 120 μg MenB-FHbp. hSBA titres peaked at 1 month after the third primary dose of MenB-FHbp and then declined over time. 24 months after the third dose in the toddler study, the proportions with hSBA titres at or above the LLOQ ranged from 0·0% (0·0-17·6; 0 of 19 participants) to 41·2% (18·4-67·1; seven of 17) in those who received 60 μg MenB-FHbp and from 3·7% (0·8-10·4; three of 81) to 22·8% (14·1-33·6; 18 of 79) in those who received 120 μg MenB-FHbp. 1 month after the booster dose in toddlers, the proportions with hSBA titres at or above the LLOQ were higher than at 1 month after the primary series. MenB-FHbp reactogenicity was mostly transient and of mild to moderate severity. Adverse event frequency was similar between the MenB-FHbp and control groups and less frequent following MenB-FHbp booster than following primary doses. Two participants from the toddler study (both from the 120 μg MenB-FHbp group) and four from the older children study (three from the 120 μg MenB-FHbp group and one from the control group) were withdrawn from the study because of adverse events.

INTERPRETATION

MenB-FHbp was well tolerated and induced protective immune responses in a high proportion of participants. These findings support a favourable MenB-FHbp immunogenicity and reactogenicity profile in young children, a population at increased risk of adverse invasive meningococcal disease outcomes.

FUNDING

Pfizer.

Plain language summary of Pfizer-BioNTech BNT162b2 COVID-19 vaccine safety in participants 16 years or older and protection against COVID-19 in participants 12 years or older

What is this summary about?

This is a summary of an article about part of a clinical study for the BNT162b2 COVID-19 vaccine, also called the Pfizer-BioNTech vaccine. The article was published in the New England Journal of Medicine in September 2021. The part of the study described in the article began in July 2020 and is ongoing. This means that the final results may be different from the results included in this summary.

What happened in this study?

The participants in this study received 2 injections of either the BNT162b2 vaccine or a placebo, 21 days apart. The placebo looked like the BNT162b2 vaccine but had no active vaccine in it. None of the trial participants or study teams knew who received vaccine or placebo.

What were the results?

Most of the reactions to the injections were mild or moderate and lasted for a short period of time. The most common reactions were pain at the injection site, extreme tiredness (fatigue), and headache. These reactions usually happened in the first 7 days after receiving a vaccine dose. A small number of participants had severe reactions to the vaccine. Compared to participants who received the placebo, participants who received the BNT162b2 vaccine were much less likely to become ill if they were infected with the virus that causes COVID-19. The vaccine also had very good efficacy at preventing severe COVID-19. Participants in South Africa who received the BNT162b2 vaccine were less likely to become ill after infection with the beta variant of the virus compared to participants who received the placebo. The beta variant was very common in South Africa when the study was taking place. Clinical Trial Registration: NCT04368728 ( ClinicalTrials.gov )

Safety and Efficacy of a Third Dose of BNT162b2 Covid-19 Vaccine

BACKGROUND

Active immunization with the BNT162b2 vaccine (Pfizer-BioNTech) has been a critical mitigation tool against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during the coronavirus disease 2019 (Covid-19) pandemic. In light of reports of waning protection occurring 6 months after the primary two-dose vaccine series, data are needed on the safety and efficacy of offering a third (booster) dose in persons 16 years of age or older.

METHODS

In this ongoing, placebo-controlled, randomized, phase 3 trial, we assigned participants who had received two 30-μg doses of the BNT162b2 vaccine at least 6 months earlier to be injected with a third dose of the BNT162b2 vaccine or with placebo. We assessed vaccine safety and efficacy against Covid-19 starting 7 days after the third dose.

RESULTS

A total of 5081 participants received a third BNT162b2 dose and 5044 received placebo. The median interval between dose 2 and dose 3 was 10.8 months in the vaccine group and 10.7 months in the placebo group; the median follow-up was 2.5 months. Local and systemic reactogenicity events from the third dose were generally of low grade. No new safety signals were identified, and no cases of myocarditis or pericarditis were reported. Among the participants without evidence of previous SARS-CoV-2 infection who could be evaluated, Covid-19 with onset at least 7 days after dose 3 was observed in 6 participants in the vaccine group and in 123 participants in the placebo group, which corresponded to a relative vaccine efficacy of 95.3% (95% confidence interval, 89.5 to 98.3).

CONCLUSIONS

A third dose of the BNT162b2 vaccine administered a median of 10.8 months after the second dose provided 95.3% efficacy against Covid-19 as compared with two doses of the BNT162b2 vaccine during a median follow-up of 2.5 months. (Funded by BioNTech and Pfizer; C4591031 ClinicalTrials.gov number, NCT04955626.).

Safety data from the MenB-FHbp clinical development program in healthy individuals aged 10 years and older

BACKGROUND

The MenB-FHbp vaccine (Trumenba®) is licensed in various countries for the prevention of meningococcal serogroup B disease in individuals ≥ 10 years of age. The clinical development program included 11 completed trials where, in each trial, MenB-FHbp had an acceptable safety profile after a primary vaccination series was administered to individuals 10-65 years of age. However, the detection of potential rare events was limited because of individual clinical trial size. The current safety analysis evaluates pooled reactogenicity and other adverse events (AEs) reported in these trials to identify new safety signals not detectable in individual trials.

METHODS

Eleven trials contributed safety data, of which 10 recorded local and systemic reactogenicity events; 8 of the trials were controlled, and reactogenicity data were pooled for 7 of these 8 trials. Additional AE evaluations included immediate AEs (IAEs), medically attended AEs (MAEs), serious AEs (SAEs), newly diagnosed chronic medical conditions (NDCMCs), and autoimmune or neuroinflammatory conditions.

RESULTS

Local and systemic reactions were more frequent in the MenB-FHbp group (n = 15,294) compared with controls (n = 5509), although most reactions were transient and mild to moderate in severity. Frequencies of IAEs, SAEs, MAEs, NDCMCs, and autoimmune or neuroinflammatory conditions were similar between the MenB-FHbp and control groups.

CONCLUSIONS

MenB-FHbp demonstrated a favorable safety and tolerability profile in the clinical development program of > 15,000 vaccine recipients ≥ 10 years of age. No new safety signals were identified in the pooled analysis compared with data from the individual trials. Continued postmarketing safety surveillance is important for the identification of rare events. Clinicaltrials.gov: NCT01299480; NCT000808028; NCT00879814; NCT00780806; NCT01352845; NCT01352793; NCT01461993; NCT01323270; NCT01830855; NCT01461980; NCT01768117.

Evaluation of the BNT162b2 Covid-19 Vaccine in Children 5 to 11 Years of Age

BACKGROUND

Safe, effective vaccines against coronavirus disease 2019 (Covid-19) are urgently needed in children younger than 12 years of age.

METHODS

A phase 1, dose-finding study and an ongoing phase 2-3 randomized trial are being conducted to investigate the safety, immunogenicity, and efficacy of two doses of the BNT162b2 vaccine administered 21 days apart in children 6 months to 11 years of age. We present results for 5-to-11-year-old children. In the phase 2-3 trial, participants were randomly assigned in a 2:1 ratio to receive two doses of either the BNT162b2 vaccine at the dose level identified during the open-label phase 1 study or placebo. Immune responses 1 month after the second dose of BNT162b2 were immunologically bridged to those in 16-to-25-year-olds from the pivotal trial of two 30-μg doses of BNT162b2. Vaccine efficacy against Covid-19 at 7 days or more after the second dose was assessed.

RESULTS

During the phase 1 study, a total of 48 children 5 to 11 years of age received 10 μg, 20 μg, or 30 μg of the BNT162b2 vaccine (16 children at each dose level). On the basis of reactogenicity and immunogenicity, a dose level of 10 μg was selected for further study. In the phase 2-3 trial, a total of 2268 children were randomly assigned to receive the BNT162b2 vaccine (1517 children) or placebo (751 children). At data cutoff, the median follow-up was 2.3 months. In the 5-to-11-year-olds, as in other age groups, the BNT162b2 vaccine had a favorable safety profile. No vaccine-related serious adverse events were noted. One month after the second dose, the geometric mean ratio of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralizing titers in 5-to-11-year-olds to those in 16-to-25-year-olds was 1.04 (95% confidence interval [CI], 0.93 to 1.18), a ratio meeting the prespecified immunogenicity success criterion (lower bound of two-sided 95% CI, >0.67; geometric mean ratio point estimate, ≥0.8). Covid-19 with onset 7 days or more after the second dose was reported in three recipients of the BNT162b2 vaccine and in 16 placebo recipients (vaccine efficacy, 90.7%; 95% CI, 67.7 to 98.3).

CONCLUSIONS

A Covid-19 vaccination regimen consisting of two 10-μg doses of BNT162b2 administered 21 days apart was found to be safe, immunogenic, and efficacious in children 5 to 11 years of age. (Funded by BioNTech and Pfizer; ClinicalTrials.gov number, NCT04816643.).

A phase 3 study to assess the immunogenicity, safety, and tolerability of MenB-FHbp administered as a 2-dose schedule in adolescents and young adults

BACKGROUND

The MenB-FHbp vaccine is licensed to prevent meningococcal serogroup B disease on either a 2-dose (0, 6 months) or 3-dose (0, 1-2, 6 months) series. This phase 3 study further assessed the immunogenicity and safety of the 2-dose MenB-FHbp schedule.

METHODS

Subjects 10-25 years of age received MenB-FHbp (months 0, 6) and the quadrivalent meningococcal conjugate vaccine MenACWY-CRM (month 0). Primary immunogenicity endpoints included percentages of subjects achieving ≥ 4-fold increases from baseline in serum bactericidal antibody using human complement (hSBA) titers for 4 diverse, vaccine-heterologous primary serogroup B test strains and titers ≥ lower limit of quantitation (LLOQ; 1:8 or 1:16) for all 4 primary strains combined (composite response) after dose 2; a titer ≥ 1:4 is the accepted correlate of protection. Percentages of participants with hSBA titers ≥ LLOQ for 10 additional vaccine-heterologous strains were also assessed; positive predictive values of primary strain responses for secondary strain responses were determined. Safety was assessed.

RESULTS

Overall, 1057 subjects received dose 1 and 946 received dose 2 of MenB-FHbp. Percentages of participants achieving ≥ 4-fold increases in hSBA titers against each primary strain after dose 2 ranged from 67.4% to 95.0% and the composite response was 74.3%. Primary strain responses were highly predictive of secondary strain responses. Most reactogenicity events were mild-to-moderate in severity and did not lead to withdrawal from the study. Adverse events (AEs) considered by the investigator to be related to vaccination occurred in 4.2% (44/1057) of subjects, and there were no serious AEs or newly diagnosed chronic medical conditions considered related to vaccination.

CONCLUSIONS

MenB-FHbp administered at 0, 6 months was well tolerated and induced protective bactericidal antibody responses against diverse serogroup B strains. Findings provide further support for the continued use of MenB-FHbp on a 2-dose schedule in this population.

Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine through 6 Months

BACKGROUND

BNT162b2 is a lipid nanoparticle-formulated, nucleoside-modified RNA vaccine encoding a prefusion-stabilized, membrane-anchored severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) full-length spike protein. BNT162b2 is highly efficacious against coronavirus disease 2019 (Covid-19) and is currently approved, conditionally approved, or authorized for emergency use worldwide. At the time of initial authorization, data beyond 2 months after vaccination were unavailable.

METHODS

In an ongoing, placebo-controlled, observer-blinded, multinational, pivotal efficacy trial, we randomly assigned 44,165 participants 16 years of age or older and 2264 participants 12 to 15 years of age to receive two 30-μg doses, at 21 days apart, of BNT162b2 or placebo. The trial end points were vaccine efficacy against laboratory-confirmed Covid-19 and safety, which were both evaluated through 6 months after vaccination.

RESULTS

BNT162b2 continued to be safe and have an acceptable adverse-event profile. Few participants had adverse events leading to withdrawal from the trial. Vaccine efficacy against Covid-19 was 91.3% (95% confidence interval [CI], 89.0 to 93.2) through 6 months of follow-up among the participants without evidence of previous SARS-CoV-2 infection who could be evaluated. There was a gradual decline in vaccine efficacy. Vaccine efficacy of 86 to 100% was seen across countries and in populations with diverse ages, sexes, race or ethnic groups, and risk factors for Covid-19 among participants without evidence of previous infection with SARS-CoV-2. Vaccine efficacy against severe disease was 96.7% (95% CI, 80.3 to 99.9). In South Africa, where the SARS-CoV-2 variant of concern B.1.351 (or beta) was predominant, a vaccine efficacy of 100% (95% CI, 53.5 to 100) was observed.

CONCLUSIONS

Through 6 months of follow-up and despite a gradual decline in vaccine efficacy, BNT162b2 had a favorable safety profile and was highly efficacious in preventing Covid-19. (Funded by BioNTech and Pfizer; ClinicalTrials.gov number, NCT04368728.).

Safety, Immunogenicity, and Efficacy of the BNT162b2 Covid-19 Vaccine in Adolescents

BACKGROUND

Until very recently, vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had not been authorized for emergency use in persons younger than 16 years of age. Safe, effective vaccines are needed to protect this population, facilitate in-person learning and socialization, and contribute to herd immunity.

METHODS

In this ongoing multinational, placebo-controlled, observer-blinded trial, we randomly assigned participants in a 1:1 ratio to receive two injections, 21 days apart, of 30 μg of BNT162b2 or placebo. Noninferiority of the immune response to BNT162b2 in 12-to-15-year-old participants as compared with that in 16-to-25-year-old participants was an immunogenicity objective. Safety (reactogenicity and adverse events) and efficacy against confirmed coronavirus disease 2019 (Covid-19; onset, ≥7 days after dose 2) in the 12-to-15-year-old cohort were assessed.

RESULTS

Overall, 2260 adolescents 12 to 15 years of age received injections; 1131 received BNT162b2, and 1129 received placebo. As has been found in other age groups, BNT162b2 had a favorable safety and side-effect profile, with mainly transient mild-to-moderate reactogenicity (predominantly injection-site pain [in 79 to 86% of participants], fatigue [in 60 to 66%], and headache [in 55 to 65%]); there were no vaccine-related serious adverse events and few overall severe adverse events. The geometric mean ratio of SARS-CoV-2 50% neutralizing titers after dose 2 in 12-to-15-year-old participants relative to 16-to-25-year-old participants was 1.76 (95% confidence interval [CI], 1.47 to 2.10), which met the noninferiority criterion of a lower boundary of the two-sided 95% confidence interval greater than 0.67 and indicated a greater response in the 12-to-15-year-old cohort. Among participants without evidence of previous SARS-CoV-2 infection, no Covid-19 cases with an onset of 7 or more days after dose 2 were noted among BNT162b2 recipients, and 16 cases occurred among placebo recipients. The observed vaccine efficacy was 100% (95% CI, 75.3 to 100).

CONCLUSIONS

The BNT162b2 vaccine in 12-to-15-year-old recipients had a favorable safety profile, produced a greater immune response than in young adults, and was highly effective against Covid-19. (Funded by BioNTech and Pfizer; C4591001 ClinicalTrials.gov number, NCT04368728.).

BNT162b2 vaccine induces neutralizing antibodies and poly-specific T cells in humans

BNT162b2, a nucleoside-modified mRNA formulated in lipid nanoparticles that encodes the SARS-CoV-2 spike glycoprotein (S) stabilized in its prefusion conformation, has demonstrated 95% efficacy in preventing COVID-19¹. Here we extend a previous phase-I/II trial report² by presenting data on the immune response induced by BNT162b2 prime-boost vaccination from an additional phase-I/II trial in healthy adults (18-55 years old). BNT162b2 elicited strong antibody responses: at one week after the boost, SARS-CoV-2 serum geometric mean 50% neutralizing titres were up to 3.3-fold above those observed in samples from individuals who had recovered from COVID-19. Sera elicited by BNT162b2 neutralized 22 pseudoviruses bearing the S of different SARS-CoV-2 variants. Most participants had a strong response of IFNγ⁺ or IL-2⁺ CD8⁺ and CD4⁺ T helper type 1 cells, which was detectable throughout the full observation period of nine weeks following the boost. Using peptide-MHC multimer technology, we identified several BNT162b2-induced epitopes that were presented by frequent MHC alleles and conserved in mutant strains. One week after the boost, epitope-specific CD8⁺ T cells of the early-differentiated effector-memory phenotype comprised 0.02-2.92% of total circulating CD8⁺ T cells and were detectable (0.01-0.28%) eight weeks later. In summary, BNT162b2 elicits an adaptive humoral and poly-specific cellular immune response against epitopes that are conserved in a broad range of variants, at well-tolerated doses.

Persistence of hSBA titers elicited by the meningococcal serogroup B vaccine menB-FHbp for up to 4 years after a 2- or 3-dose primary series and immunogenicity, safety, and tolerability of a booster dose through 26 months

BACKGROUND

To demonstrate extended protection against meningococcal serogroup B (MenB) disease after MenB-FHbp (bivalent rLP2086) vaccination, this study evaluated immunopersistence through 26 months following MenB-FHbp boosting after 2 or 3 primary doses in adolescents.

STUDY DESIGN

This phase 3, open-label study was an extension of 3 phase 2 studies with participants aged 11-18 years randomized to receive primary MenB-FHbp vaccination following 1 of 5 dosing schedules or control. A booster dose was administered 48 months after the primary series. Immunopersistence through 48 months after the last primary dose (persistence stage) and 26 months postbooster (booster stage) was determined by serum bactericidal assays using human complement (hSBAs) against 4 vaccine-heterologous test strains. Safety evaluations included adverse events (AEs) and local and systemic reactions.

RESULTS

Overall, 698 and 304 subjects enrolled in the persistence and booster stages, respectively. hSBA titers declined in all groups during 12 months postprimary vaccination, then remained stable through 48 months. One month postbooster, 93.4-100.0% of subjects achieved hSBA titers ≥ lower limit of quantitation against each test strain; percentages at 12 and 26 months postbooster were higher than at similar time points following primary vaccination. Primary and booster MenB-FHbp vaccinations were well tolerated, with ≤ 12.5% of subjects reporting AEs during each stage. The most common local (reported by 84.4-93.8% of subjects) and systemic (68.8-76.6%) reactions to the booster were injection site pain and fatigue and headache, respectively; ≤ 3.7% of subjects reported severe systemic events.

CONCLUSION

Protective hSBA titers initially declined but were retained by many subjects for 4 years irrespective of primary MenB-FHbp vaccination schedule. Boosting at 48 months after primary vaccination was safe, well tolerated, and induced immune responses indicative of immunological memory that persisted through 26 months. Booster vaccination during late adolescence may prolong protection against MenB disease.

Ten-Year Antibody Persistence and Booster Response to MenACWY-TT Vaccine After Primary Vaccination at 1-10 Years of Age

This phase 3B, open-label, extension study (NCT01962207) evaluated long-term persistence of antibodies induced by the quadrivalent meningococcal vaccine conjugated to tetanus toxoid (MenACWY-TT) compared with the meningococcal serogroup C vaccine conjugated to CRM (MenC-CRM) and the quadrivalent meningococcal polysaccharide vaccine (MenACWY-PS) 6 to 10 y after primary vaccination in toddlers (aged 1–<2 y; MenACWY-TT and MenC-CRM) and children (aged 2–<11 y; MenACWY-TT and MenACWY-PS). Antibody responses against meningococcal serogroups A, C, W, and Y were assessed by serum bactericidal antibody assays using rabbit (rSBA) or human (hSBA) complement. A MenACWY-TT booster dose at Year 10 was given to all eligible subjects regardless of the primary vaccine received. At Year 10, the percentages of subjects with rSBA titers ≥1:8 for serogroups A, C, W, and Y were as follows: MenACWY-TT (toddlers), 65.6%, 82.8%, 31.3%, 43.8%, respectively; MenC-CRM, 88.2% for serogroup C; MenACWY-TT (children), 88.9%, 84.1%, 67.1%, 65.9%; and MenACWY-PS, 28.6%, 81.0%, 23.8%, and 23.8%. Corresponding percentages for hSBA titers ≥1:4 were as follows: MenACWY-TT (toddlers), 31.1%, 91.9%, 44.4%, 41.4%; MenC-CRM, 93.8% for serogroup C; MenACWY-TT (children), 34.8%, 91.1%, 61.2%, 72.6%; and MenACWY-PS, 33.3%, 100.0%, 26.3%, and 44.4%. One month after the MenACWY-TT booster, the percentage of subjects with vaccine response ranged from 75.7% to 100.0% across serogroups in all study groups. Postbooster vaccine responses were generally comparable between groups across serogroups. No new safety signals were identified. Antibody responses persisted 10 y after MenACWY-TT vaccination. The MenACWY-TT booster dose was well tolerated and elicited robust immune responses.

BNT162b2 vaccine induces neutralizing antibodies and poly-specific T cells in humans

BNT162b2, a nucleoside-modified mRNA formulated in lipid nanoparticles that encodes the SARS-CoV-2 spike glycoprotein (S) stabilized in its prefusion conformation, has demonstrated 95% efficacy in preventing COVID-19¹. Here we extend a previous phase-I/II trial report² by presenting data on the immune response induced by BNT162b2 prime-boost vaccination from an additional phase-I/II trial in healthy adults (18-55 years old). BNT162b2 elicited strong antibody responses: at one week after the boost, SARS-CoV-2 serum geometric mean 50% neutralizing titres were up to 3.3-fold above those observed in samples from individuals who had recovered from COVID-19. Sera elicited by BNT162b2 neutralized 22 pseudoviruses bearing the S of different SARS-CoV-2 variants. Most participants had a strong response of IFNγ⁺ or IL-2⁺ CD8⁺ and CD4⁺ T helper type 1 cells, which was detectable throughout the full observation period of nine weeks following the boost. Using peptide-MHC multimer technology, we identified several BNT162b2-induced epitopes that were presented by frequent MHC alleles and conserved in mutant strains. One week after the boost, epitope-specific CD8⁺ T cells of the early-differentiated effector-memory phenotype comprised 0.02-2.92% of total circulating CD8⁺ T cells and were detectable (0.01-0.28%) eight weeks later. In summary, BNT162b2 elicits an adaptive humoral and poly-specific cellular immune response against epitopes that are conserved in a broad range of variants, at well-tolerated doses.

Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the resulting coronavirus disease 2019 (Covid-19) have afflicted tens of millions of people in a worldwide pandemic. Safe and effective vaccines are needed urgently.

METHODS

In an ongoing multinational, placebo-controlled, observer-blinded, pivotal efficacy trial, we randomly assigned persons 16 years of age or older in a 1:1 ratio to receive two doses, 21 days apart, of either placebo or the BNT162b2 vaccine candidate (30 μg per dose). BNT162b2 is a lipid nanoparticle-formulated, nucleoside-modified RNA vaccine that encodes a prefusion stabilized, membrane-anchored SARS-CoV-2 full-length spike protein. The primary end points were efficacy of the vaccine against laboratory-confirmed Covid-19 and safety.

RESULTS

A total of 43,548 participants underwent randomization, of whom 43,448 received injections: 21,720 with BNT162b2 and 21,728 with placebo. There were 8 cases of Covid-19 with onset at least 7 days after the second dose among participants assigned to receive BNT162b2 and 162 cases among those assigned to placebo; BNT162b2 was 95% effective in preventing Covid-19 (95% credible interval, 90.3 to 97.6). Similar vaccine efficacy (generally 90 to 100%) was observed across subgroups defined by age, sex, race, ethnicity, baseline body-mass index, and the presence of coexisting conditions. Among 10 cases of severe Covid-19 with onset after the first dose, 9 occurred in placebo recipients and 1 in a BNT162b2 recipient. The safety profile of BNT162b2 was characterized by short-term, mild-to-moderate pain at the injection site, fatigue, and headache. The incidence of serious adverse events was low and was similar in the vaccine and placebo groups.

CONCLUSIONS

A two-dose regimen of BNT162b2 conferred 95% protection against Covid-19 in persons 16 years of age or older. Safety over a median of 2 months was similar to that of other viral vaccines. (Funded by BioNTech and Pfizer; ClinicalTrials.gov number, NCT04368728.).

3. A Review of the Clinical Development of MenACWY-TT, a Quadrivalent Meningococcal Vaccine Conjugated to Tetanus Toxoid, in Adolescents

Background

As a peak in meningococcal disease often occurs during adolescence, meningococcal vaccination programs are available for this age group in various regions across the globe. Quadrivalent meningococcal (MenACWY) conjugate vaccines are being incorporated in an increasing number of programs in response to changing meningococcal serogroup epidemiology. MenACWY-TT (Nimenrix®) is a MenACWY conjugate vaccine available in the European Union and 50 other countries for preventive vaccination of serogroup A, C, W, and Y disease (Figure 1). MenACWY-TT is licensed in some countries as a 2-dose primary series in individuals as young as 6 weeks of age, while a single dose may be given to previously unvaccinated individuals ≥ 6 months of age, adolescents, and adults. Here, we provide an overview of the 3 primary and 5 extension studies evaluating the clinical development of MenACWY-TT in adolescents (Table 1).

Figure 1. Global Registration Status of MenACWY-TT (Nimenrix®) in Adolescents

Table 1. Pivotal Clinical Studies of MenACWY-TT (Nimenrix®) Supporting Licensure in Adolescents

Methods

Immunogenicity and safety data from these 8 clinical studies are summarized.

Results

Across studies, MenACWY-TT antibody responses against all vaccine serogroups were comparable to those of other MenACWY vaccines 1 month post vaccination (Table 1). Antibody responses to MenACWY-TT persisted for up to 10 years in those vaccinated during adolescence. A MenACWY-TT booster given 10 years after primary meningococcal vaccination in early childhood or adolescence elicited robust antibody responses. MenACWY-TT had an acceptable safety profile, with reactogenicity events most commonly reported. Reactogenicity profiles with MenACWY-TT booster were similar to those seen after primary MenACWY-TT.

Conclusion

The MenACWY-TT clinical study program demonstrated the immunogenicity and safety of primary and booster dosing in adolescents. Immune responses persisted through 10 years after primary vaccination.

Funding

Pfizer.

Disclosures

Paula Peyrani, MD, Pfizer Inc (Employee, Shareholder) Chris Webber, MD, Pfizer Inc (Employee, Shareholder) Cindy Burman, PharmD, Pfizer Inc (Employee, Shareholder) Paul Balmer, PhD, Pfizer Inc (Employee, Shareholder) John L. Perez, MD, MA, Pfizer Inc (Employee, Shareholder)

4. MenACWY-TT Long-Term Antibody Persistence Following Adolescent Vaccination and Evaluation of a Booster Dose: A Review of Clinical Data

Background

A peak in meningococcal carriage and invasive meningococcal disease (IMD) occurs during adolescence and young adulthood. In the United States, preventive vaccination with a quadrivalent meningococcal (MenACWY) conjugate vaccine is recommended at age 11–12 years, with a booster dose given at age 16 years. MenACWY-TT (Nimenrix®), a MenACWY tetanus toxoid conjugate vaccine, was first licensed in 2012 and is available in the European Union and 50 other countries. Immune responses to other MenACWY conjugate vaccines decline over several years following vaccination. Here, we review 2 recent studies evaluating the long-term persistence of MenACWY-TT immune responses in adolescents as well as safety and immunogenicity of a booster dose given 10 years after primary vaccination.

Methods

Both studies (ClinicalTrials.gov NCT01934140, NCT03189745) were extensions of phase 2 or 3 studies of subjects 11–17 years of age given a single dose of MenACWY-TT or MenACWY polysaccharide vaccine (MenACWY-PS). Immune responses through 10 years after primary vaccination and after a Year 10 MenACWY-TT booster dose were measured by serum bactericidal antibody assays using baby rabbit complement (rSBA). Specific endpoints included percentages of subjects with rSBA titers ≥1:8 and ≥1:128 and geometric mean titers (GMTs). Booster dose safety and tolerability were also evaluated.

Results

In both studies, the percentages of subjects with rSBA titers ≥1:8 through 10 years postvaccination were generally higher or similar among MenACWY-TT (69.3%–91.2% at Year 10; n=137–163) compared with MenACWY-PS (24.4%–88.9%; n=45–53) recipients for all 4 serogroups (Figure); similar results were observed for GMTs (146.0–446.9 vs 12.9–191.0 at Year 10). One month after a MenACWY-TT booster dose, 97.7%–100% of subjects across groups had titers ≥1:8 (Figure), and GMTs were markedly higher than prebooster values. No new safety signals were identified following the booster dose.

Figure 1. Subjects in each of the 2 studies with rSBA titers ≥1:8 before and at 1 month, 5 years, and 10 years after primary vaccination with MenACWY-TT or MenACWY-PS at 11–17 years of age and 1 month after booster vaccination with MenACWY-TT at 10 years following primary vaccination.

Conclusion

Functional antibodies for all 4 serogroups persisted through 10 years after MenACWY-TT adolescent vaccination, suggesting that this vaccine may help prevent IMD throughout the lengthy risk period in this group. A MenACWY-TT booster dose may further extend protection regardless of the primary vaccine received.

Funded by Pfizer.

Disclosures

Paula Peyrani, MD, Pfizer Inc (Employee, Shareholder) Chris Webber, MD, Pfizer Inc (Employee, Shareholder) Cindy Burman, PharmD, Pfizer Inc (Employee, Shareholder) Paul Balmer, PhD, Pfizer Inc (Employee, Shareholder) John L. Perez, MD, MA, Pfizer Inc (Employee, Shareholder)

6. Pentavalent Meningococcal (MenABCWY) Vaccine is Safe and Well Tolerated With Immunogenicity Noninferior to Coadministered MenB-FHbp and MenACWY-CRM in a Phase 2 Study of Healthy Adolescents and Young Adults

Background

Meningococcal serogroups A, B, C, W and Y cause nearly all meningococcal disease globally. Vaccination is complicated by different dosing recommendations for serogroup B (MenB) and quadrivalent (MenACWY) vaccines, which could be solved with a single pentavalent vaccine. This study in adolescents and young adults evaluated a new pentavalent MenABCWY vaccine that combines 2 licensed vaccines, MenB-FHbp (Trumenba®; bivalent rLP2086) and MenACWY-TT (Nimenrix®), into a single vaccine.

Methods

In this ongoing, randomized, controlled, observer-blinded, multicenter study (NCT03135834), MenB vaccine-naive and MenACWY-naive or -experienced healthy 10–25-year-olds were randomized 1:2 to MenABCWY (Month 0,6) or MenB-FHbp (Month 0,6) and MenACWY-CRM (Month 0). Immune responses were measured by serum bactericidal activity assays with human complement (hSBA) against serogroup A, C, W and Y strains and 4 diverse, vaccine-heterologous MenB strains. Endpoints included percentages of subjects achieving ≥ 4-fold rises in titers from baseline. Noninferiority of immune responses was assessed at the 10% margin (95% CI lower limit &gt; −10%). Safety was assessed.

Results

Following dose 2, high percentages of MenABCWY (n=543) and MenB-FHbp (n=1057) recipients achieved ≥ 4-fold rises against each of the 4 MenB strains (75.8−94.7% vs 67.4−95.0%) and titers reaching at least the lower limit of quantification against all 4 strains combined (79.9% vs 74.3%; Figure 1A). MenABCWY was noninferior to MenB-FHbp for all 5 endpoints. MenABCWY was also noninferior to a single MenACWY-CRM dose with 75.5−96.9% and 93.0−97.4% of MenABCWY recipients after dose 1 or 2, respectively, achieving ≥ 4-fold rises against serogroup A, C, W and Y depending on prior MenACWY experience (Figure 1B). Local reactions and systemic events after MenABCWY or MenB-FHbp were similarly frequent, mostly mild/moderate in severity (Figure 2), and unaffected by MenACWY experience.

Figure 1. Immune Responses as Measured in hSBA to (A) MenB Test Strains at 1 Month After Dose 2 and (B) MenA, MenC, MenW, and MenY Test Strains at 1 Month After Doses 1 and 2

Conclusion

MenABCWY 4-fold immune responses from baseline were robust and noninferior to MenB-FHbp and MenACWY-CRM administered separately. Vaccination was safe and well tolerated. The favorable benefit-risk profile supports further MenABCWY development as a simplified alternative to current meningococcal vaccination practices. Funded by Pfizer.

Disclosures

James Peterson, MD, Pfizer (Scientific Research Study Investigator) Daniel Drazan, MD, Pfizer (Scientific Research Study Investigator) Hanna Czajka, MD, PhD, Pfizer (Scientific Research Study Investigator) Jason Maguire, MD, Pfizer (Employee, Shareholder) Jean-Louis Pregaldien, MS, Pfizer (Employee, Shareholder) Ilkka Seppa, MD, Pfizer (Scientific Research Study Investigator) Roger Maansson, MS, Pfizer (Employee, Shareholder) Robert O’Neill, PhD, Pfizer (Employee, Shareholder) Annaliesa S. Anderson, PhD, Pfizer (Employee, Shareholder) Paul Balmer, PhD, Pfizer Inc (Employee, Shareholder) Johannes Beeslaar, MD, Pfizer (Employee, Shareholder) John L. Perez, MD, MA, Pfizer Inc (Employee, Shareholder)

Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the resulting coronavirus disease 2019 (Covid-19) have afflicted tens of millions of people in a worldwide pandemic. Safe and effective vaccines are needed urgently.

METHODS

In an ongoing multinational, placebo-controlled, observer-blinded, pivotal efficacy trial, we randomly assigned persons 16 years of age or older in a 1:1 ratio to receive two doses, 21 days apart, of either placebo or the BNT162b2 vaccine candidate (30 μg per dose). BNT162b2 is a lipid nanoparticle-formulated, nucleoside-modified RNA vaccine that encodes a prefusion stabilized, membrane-anchored SARS-CoV-2 full-length spike protein. The primary end points were efficacy of the vaccine against laboratory-confirmed Covid-19 and safety.

RESULTS

A total of 43,548 participants underwent randomization, of whom 43,448 received injections: 21,720 with BNT162b2 and 21,728 with placebo. There were 8 cases of Covid-19 with onset at least 7 days after the second dose among participants assigned to receive BNT162b2 and 162 cases among those assigned to placebo; BNT162b2 was 95% effective in preventing Covid-19 (95% credible interval, 90.3 to 97.6). Similar vaccine efficacy (generally 90 to 100%) was observed across subgroups defined by age, sex, race, ethnicity, baseline body-mass index, and the presence of coexisting conditions. Among 10 cases of severe Covid-19 with onset after the first dose, 9 occurred in placebo recipients and 1 in a BNT162b2 recipient. The safety profile of BNT162b2 was characterized by short-term, mild-to-moderate pain at the injection site, fatigue, and headache. The incidence of serious adverse events was low and was similar in the vaccine and placebo groups.

CONCLUSIONS

A two-dose regimen of BNT162b2 conferred 95% protection against Covid-19 in persons 16 years of age or older. Safety over a median of 2 months was similar to that of other viral vaccines. (Funded by BioNTech and Pfizer; ClinicalTrials.gov number, NCT04368728.).

Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the resulting coronavirus disease 2019 (Covid-19) have afflicted tens of millions of people in a worldwide pandemic. Safe and effective vaccines are needed urgently.

METHODS

In an ongoing multinational, placebo-controlled, observer-blinded, pivotal efficacy trial, we randomly assigned persons 16 years of age or older in a 1:1 ratio to receive two doses, 21 days apart, of either placebo or the BNT162b2 vaccine candidate (30 μg per dose). BNT162b2 is a lipid nanoparticle-formulated, nucleoside-modified RNA vaccine that encodes a prefusion stabilized, membrane-anchored SARS-CoV-2 full-length spike protein. The primary end points were efficacy of the vaccine against laboratory-confirmed Covid-19 and safety.

RESULTS

A total of 43,548 participants underwent randomization, of whom 43,448 received injections: 21,720 with BNT162b2 and 21,728 with placebo. There were 8 cases of Covid-19 with onset at least 7 days after the second dose among participants assigned to receive BNT162b2 and 162 cases among those assigned to placebo; BNT162b2 was 95% effective in preventing Covid-19 (95% credible interval, 90.3 to 97.6). Similar vaccine efficacy (generally 90 to 100%) was observed across subgroups defined by age, sex, race, ethnicity, baseline body-mass index, and the presence of coexisting conditions. Among 10 cases of severe Covid-19 with onset after the first dose, 9 occurred in placebo recipients and 1 in a BNT162b2 recipient. The safety profile of BNT162b2 was characterized by short-term, mild-to-moderate pain at the injection site, fatigue, and headache. The incidence of serious adverse events was low and was similar in the vaccine and placebo groups.

CONCLUSIONS

A two-dose regimen of BNT162b2 conferred 95% protection against Covid-19 in persons 16 years of age or older. Safety over a median of 2 months was similar to that of other viral vaccines. (Funded by BioNTech and Pfizer; ClinicalTrials.gov number, NCT04368728.).

MenB-FHbp Vaccine Protects Against Diverse Meningococcal Strains in Adolescents and Young Adults: Post Hoc Analysis of Two Phase 3 Studies

Introduction

Two phase 3 studies in adolescents and young adults demonstrated that MenB-FHbp, a meningococcal serogroup B (MenB) vaccine, elicits protective immune responses after 2 or 3 doses based on serum bactericidal antibody assays using human complement (hSBA) against 4 primary and 10 additional diverse, vaccine-heterologous MenB test strains. Lower limits of quantitation (LLOQs; titers 1:8 or 1:16; titers ≥ 1:4 correlate with protection) were used to evaluate responses to individual strains and all 4 primary strains combined (composite response). A post hoc analysis evaluated percentages of subjects with protective responses to as many as 8 strains combined (4 primary plus additional strains).

Methods

Immune responses were measured using hSBAs against 4 primary strains in adolescents (n = 1509, MenB-FHbp; n = 898, hepatitis A virus vaccine/saline) and young adults (n = 2480, MenB-FHbp; n = 824, saline) receiving MenB-FHbp or control at 0, 2, and 6 months. Ten additional strains were evaluated in subsets of subjects from approximately 1800 MenB-FHbp recipients across both studies. Percentages of subjects with hSBA titers ≥ LLOQ for different numbers of primary strains or primary plus additional strains combined (7 or 8 strains total per subset) were determined before vaccination, 1 month post-dose 2, and 1 month post-dose 3.

Results

Across the panel of primary plus additional strains, at 1 month post-dose 3, titers ≥ LLOQ were elicited in 93.7–95.7% of adolescents and 91.7–95.0% of young adults for ≥ 5 test strains combined and in 70.5–85.8% of adolescents and 67.5–81.4% of young adults for ≥ 7 strains combined. Among adolescents, 99.8%, 99.0%, 92.8%, and 82.7% had titers ≥ LLOQ against at least 1, 2, 3, and all 4 primary strains, respectively; corresponding percentages for young adults were 99.7%, 97.7%, 94.0%, and 84.5%.

Conclusions

Results support the ability of MenB-FHbp to provide broad coverage against MenB strains expressing diverse FHbp variants.

Trial Registration

ClinicalTrials.gov identifiers NCT01830855, NCT01352845.

Electronic supplementary material

The online version of this article (10.1007/s40121-020-00319-0) contains supplementary material, which is available to authorized users.

A phase 2b/3b MenACWY-TT study of long-term antibody persistence after primary vaccination and immunogenicity and safety of a booster dose in individuals aged 11 through 55 years

BACKGROUND

A previous phase 2 study demonstrated the immunogenicity of a single dose of meningococcal A, C, W, Y-tetanus toxoid conjugate (MenACWY-TT) or polysaccharide (MenACWY-PS) vaccine for up to 5 years in individuals aged 11-55 years. This follow-up study evaluated long-term antibody persistence up to 10 years and the immunogenicity and safety of a single MenACWY-TT booster dose given 10 years after primary vaccination.

METHODS

Blood draws were conducted annually in Years 7-10. At Year 10, all subjects received a MenACWY-TT booster dose. Blood was drawn at 1 month and safety data were collected ≤6 months postbooster. Study endpoints included immunogenicity during the persistence phase (primary), and immunogenicity and safety during the booster phase (secondary). Statistical analyses were descriptive.

RESULTS

A total of 311 subjects were enrolled in the persistence phase (MenACWY-TT, 235; MenACWY-PS, 76); 220 were enrolled in the booster phase (MenACWY-TT, 164; MenACWY-PS, 56). Descriptive analyses indicated that at Years 7-10, the percentages of subjects achieving serum bactericidal antibody assay using baby rabbit complement (rSBA) titers ≥1:8 and ≥1:128 were higher for serogroups A, W, and Y in the MenACWY-TT versus MenACWY-PS group; percentages were similar across groups for serogroup C. rSBA geometric mean titers (GMTs) for serogroups A, W, and Y were higher in the MenACWY-TT group and slightly higher in the MenACWY-PS group for serogroup C. One month postbooster, all primary MenACWY-TT and ≥98.1% of primary MenACWY-PS recipients had rSBA titers ≥1:8. For all serogroups, rSBA GMTs postbooster were higher in the MenACWY-TT versus MenACWY-PS group. Most local and general reactogenicity events were similar between groups and mild to moderate in severity. Adverse events at 1 month postbooster were 9.1% for the MenACWY-TT and 3.6% for the MenACWY-PS groups; all were nonserious.

CONCLUSIONS

Immune responses to a single MenACWY-TT primary dose administered at age 11-55 years persisted in >70% of individuals evaluated at Years 7-10. A MenACWY-TT booster dose administered at Year 10 was safe and immunogenic with no new safety signals observed. These results provide important insights regarding long-term protection from primary vaccination and the benefits of booster dosing.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT01934140. Registered September 2013.

Efficacy and safety of a booster dose of the meningococcal A, C, W, Y-tetanus toxoid conjugate vaccine administered 10 years after primary vaccination and long-term persistence of tetanus toxoid conjugate or polysaccharide vaccine

A previous phase 3, randomized, multicenter study showed the immunogenicity of a primary vaccination of subjects aged 11 to 17 years with the quadrivalent meningococcal vaccine conjugated to tetanus toxoid (MenACWY-TT) or the quadrivalent meningococcal polysaccharide vaccine (MenACWY-PS). This extension study evaluated the safety and immunogenicity of a MenACWY-TT booster 10 years after receiving a primary dose of either MenACWY-TT or MenACWY-PS. The primary immunogenicity endpoint was booster response, evaluated using serum bactericidal antibody assays with rabbit complement (rSBA), 1 month postbooster. Safety endpoints included the percentage of subjects experiencing local and general adverse events (AEs) ≤4 days after MenACWY-TT booster. Of 229 subjects enrolled, 169 and 58 in the MenACWY-TT and MenACWY-PS groups, respectively, completed the booster phase. The 1 month postbooster response for each serogroup ranged from 81.5% to 95.7% for MenACWY-TT and 66.7% to 94.1% for MenACWY-PS. Similar percentages of MenACWY-TT and MenACWY-PS recipients had a booster response to serogroups A, W, and Y, whereas more MenACWY-TT recipients than MenACWY-PS recipients had a booster response to serogroup C. For the MenACWY-TT and MenACWY-PS groups, respectively, the MenACWY-TT booster elicited rSBA titers ≥1:8 in 100% and ≥98.0% of subjects across all serogroups; 100% and ≥96.1% of all subjects had titers ≥1:128. No new safety signals were observed during the booster phase. In conclusion, a MenACWY-TT booster dose after receiving either a primary dose of MenACWY-TT or MenACWY-PS elicited robust immune responses and was well tolerated. Functional antibody responses last up to 10 years after primary MenACWY-TT vaccination.

Long-term antibody persistence after a booster dose of quadrivalent meningococcal ACWY-tetanus toxoid conjugate vaccine in healthy 5-year-old children

BACKGROUND

To provide continuing protection, available meningococcal vaccines must provide long-term persistence of circulating functional antibodies against prevalent serogroups causing invasive meningococcal disease (IMD). This study assessed antibody persistence and safety of the quadrivalent meningococcal vaccine conjugated to tetanus toxoid (MenACWY-TT) and the meningococcal serogroup C vaccine conjugated to Corynebacterium diphtheriae CRM₁₉₇ protein (MenC-CRM) for up to 6 years after booster dosing in children.

METHODS

In the primary vaccination study, children were vaccinated at age 12 to 23 months. In the first extension study, children who completed the primary study received a booster dose 4 years later with the same primary vaccine. The current study assessed antibody persistence at 2 to 6 years postbooster against each of the 4 meningococcal serogroups using serum bactericidal assays using rabbit (rSBA) or human (hSBA) complement with antibody titer thresholds of ≥1:8 or ≥1:4, respectively, and geometric mean titers (GMTs). Safety evaluations during this period included serious adverse events (SAEs) related to vaccination and any event related to lack of vaccine efficacy.

RESULTS

A total of 184 subjects were enrolled (MenACWY-TT = 159; MenC-CRM = 25). For MenACWY-TT, the percentages of subjects with rSBA titers ≥1:8 ranged from 96.7% to 100% across serogroups at 2 years postbooster and 71.6% to 94.0% at 6 years postbooster; rSBA GMTs decreased from Year 2 to 4 and generally remained stable thereafter. The percentages of subjects in the MenACWY-TT group with hSBA titers ≥1:4 were 70.0% to 100% across serogroups at 2 years postbooster and 58.5% to 98.5% at 6 years postbooster. No lack of efficacy, SAEs, or vaccine-related adverse events were reported.

CONCLUSIONS

The persistence of rSBA and hSBA antibodies was shown up to 6 years postbooster (10 years postprimary vaccination) with either MenACWY-TT or MenC-CRM, suggesting that this schedule may provide long-term protection against IMD. Clinicaltrials.gov: NCT01900899.

2722. Effects of Sex, Age, and Race on Immunogenicity of MenB-FHbp, a Bivalent Meningococcal B Vaccine: A Pooled Evaluation of Clinical Trial Data

Background

MenB-FHbp (bivalent rLP2086), a meningococcal serogroup B vaccine, is approved in several countries for adolescents and young adults. MenB-FHbp elicited robust immune responses and had an acceptable safety profile during an extensive clinical development program. Because immune responses to vaccines can vary by subject demographics, this subgroup analysis pooled data across 7 randomized MenB-FHbp clinical studies to evaluate potential differences in immunogenicity by sex, age, or race/ethnicity in a larger dataset relative to individual studies.

Methods

Data from subjects who received 120 µg MenB-FHbp at 0, 2, and 6 months and had valid immunogenicity results for 4 vaccine-heterologous test strains were included. Immune responses were evaluated by serum bactericidal assays using human complement (hSBA). Immunogenicity endpoints (assessed 1 month after dose 3) were percentages of subjects achieving ≥ 4-fold rise in hSBA titer against each strain, percentages achieving hSBA titers ≥ the lower limit of quantification (LLOQ) against each strain and against all 4 strains combined (composite response), geometric mean hSBA titers against each strain, and percentages achieving hSBA titers ≥ 1:4 (correlate of protection) against each strain.

Results

This analysis included 8026 subjects aged 10‒25 years (51.7% males, 80.7% adolescents aged 10‒18 years, 87.0% white, 9.3% black, 0.8% Asian, 3.0% other race). One month after dose 3, percentages of subjects achieving a ≥ 4-fold rise from baseline titer against each strain and achieving a composite response were similar across age and race (table). A marginally greater percentage of males vs. females achieved ≥ 4-fold rise in titer against each strain, but these differences were not considered clinically meaningful because of the high percentages of responders in both groups.

Conclusion

MenB-FHbp immunogenicity was similar across sex, age, and race in this pooled analysis, with high percentages of responders in all evaluated subgroups. The marginally lower response rates among females compared with males were not considered clinically meaningful. These findings support currently recommended MenB-FHbp vaccination practices without modification by sex, age, or race.

Funding: Pfizer

Disclosures

All authors: No reported disclosures.

1478. Efficacy and Safety of a Booster Dose of the MenACWY-TT Vaccine Administered 10 Years After Primary Vaccination with MenACWY-TT or MenACWY-PS

Background

The quadrivalent meningococcal ACWY polysaccharide tetanus toxoid conjugate vaccine (MenACWY-TT; Nimenrix) is licensed in various countries to prevent disease caused by meningococcal serogroups A, C, W, and Y. In a previous study (NCT00464815), subjects aged 11‒17 years received a primary dose of MenACWY-TT or a quadrivalent polysaccharide vaccine (MenACWY-PS). Here, we report the long-term antibody persistence of the primary dose and the immunogenicity and safety of a booster dose given 10 years after primary vaccination of subjects.

Methods

Participants were enrolled from the Philippines and received a booster dose of MenACWY-TT at 10 years postvaccination. Antibody persistence 10 years postprimary vaccination and immunogenicity 1 month after the booster dose were evaluated by serum bactericidal activity assays using rabbit complement (rSBA) to assess the percentages of subjects with titers ≥1:8 and ≥1:128 and geometric mean titers (GMTs) for each serogroup. Safety was assessed for the booster dose.

Results

Of 229 subjects enrolled in this extension study, 169 and 58 subjects in the MenACWY-TT and MenACWY-PS groups, respectively, completed the booster phase. The percentages of primary MenACWY-TT recipients with prebooster rSBA titers ≥ 1:8 and ≥ 1:128 at year 10 ranged from 71.6%‒90.7% and 64.8%‒85.2% for all serogroups, respectively, compared with 43.1%‒82.4% and 25.5%‒76.5% of primary MenACWY-PS recipients; rSBA GMTs for all serogroups were higher in the MenACWY-TT group than in the MenACWY-PS group at year 10. For the MenACWY-TT and MenACWY-PS groups, respectively, the MenACWY-TT booster dose elicited rSBA titers ≥1:8 in 100% and ≥98.0% of subjects (figure); 100% and ≥96.1% of all subjects had titers ≥1:128. For all serogroups, rSBA GMTs at 1 month after the booster dose were higher than before the booster dose. No new safety signals were observed during the booster phase.

Conclusion

Functional antibody responses elicited by MenACWY-TT persisted 10 years after primary vaccination; the booster dose was well tolerated and elicited robust immune responses.

ClinicalTrials.gov: NCT03189745, EudraCT # 2013-001512-29. Funded by Pfizer.

Disclosures

All authors: No reported disclosures.

Persistence and 4-year boosting of the bactericidal response elicited by two- and three-dose schedules of MenB-FHbp: A phase 3 extension study in adolescents

BACKGROUND

The period of heightened risk of invasive meningococcal disease in adolescence extends for >10 years. This study aimed to evaluate persistence of the immune response to the serogroup B meningococcal (MenB) vaccine MenB-FHbp (Trumenba^®, Bivalent rLP2086) under two- and three-dose primary vaccination schedules, both of which are approved in the United States and the European Union, and to assess safety and immunogenicity of a booster dose.

METHODS

This was an open-label extension study of a phase 2 randomized MenB-FHbp study (primary study). This interim analysis includes data through 1 month after booster vaccination. In the primary study, adolescents 11-18 years of age were randomized using an interactive voice or web-based response system to receive 120 μg MenB-FHbp under 0-, 1-, 6-month; 0-, 2-, 6-month; 0-, 6-month; 0-, 2-month; or 0-, 4-month schedules (termed study groups for the current analysis). For the primary study, participants were blinded to their vaccine study group allocation, but investigators and the study sponsor were unblinded. Immune responses in subjects from the primary study were evaluated through 48 months after primary vaccination (persistence stage; 17 sites in Czech Republic, Denmark, Germany, and Sweden). Safety and immunogenicity of a booster dose given at 48 months after primary vaccination (booster stage; 14 sites in Czech Republic, Denmark, and Sweden) were also assessed. Immune responses were evaluated in serum bactericidal assays with human complement (hSBAs) using four MenB test strains representative of disease-causing MenB strains in the United States and Europe and expressing factor H binding proteins (FHbps) heterologous to the vaccine antigens. The primary immunogenicity endpoints were the proportions of subjects with hSBA titers greater than or equal to the assays' lower limit of quantitation (LLOQ; 1:8 or 1:16 depending on strain) at 12, 18, 24, 36, and 48 months after primary vaccination (persistence stage) and 1 and 48 months after the primary vaccination series and 1 month after receipt of the booster dose (booster stage). Safety evaluations during the booster stage included local reactions and systemic events by severity, antipyretic use, adverse events (AEs), immediate AEs, serious AEs (SAEs), medically attended AEs (MAEs), newly diagnosed chronic medical conditions (NDCMCs), and missed days of school and work because of AEs. The modified intent-to-treat (mITT) population was used for immunogenicity evaluations in the persistence stage. The booster stage immunogenicity evaluations used the evaluable immunogenicity population; analyses were also performed in the mITT population. For the persistence stage, safety evaluations included subjects with at least one blood draw, whereas for the booster stage, they included subjects who received the booster dose and had available safety data. This trial is registered at ClinicalTrials.gov number NCT01543087.

FINDINGS

A total of 465 subjects were enrolled in the persistence stage, and 271 subjects were enrolled in the booster stage. Sera for the extension phase of this interim analysis were collected from September 7, 2012 to December 7, 2015. One month after primary vaccination, 73.8-100.0% of subjects depending on study group responded with hSBA titers ≥LLOQ. Response rates declined during the 12 months after last primary vaccination and then remained stable through 48 months, with 18.0-61.3% of subjects depending on study group having hSBA titers ≥LLOQ at this time point. One month after receipt of the booster dose, 91.9-100.0% of subjects depending on study group had hSBA titers ≥LLOQ against the four primary strains individually and 91.8-98.2% had hSBA titers ≥LLOQ against all four strains combined (composite response). Geometric mean titers were higher after booster vaccination than at 1 month after primary vaccination. Immune responses were generally similar across study groups, regardless of whether a two- or three-dose primary series was received. None of the AEs (2.2-6.9% of subjects depending on study group) or NDCMCs (1.8-5.0%) that were reported during the persistence stage were considered related to the investigational product. Local reactions and systemic events were reported by 84.4-93.8% and 68.8-76.6% of subjects depending on study group, respectively, in the booster stage; these were generally similar across study groups, transient, and less frequent than after any primary vaccination. Additionally, there was no general progressive worsening in severity of reactogenicity events (ie, potentiation; ≤3 subjects per group), and reactogenicity events did not lead to any study withdrawals. No NDCMCs or immediate AEs were reported during the booster stage. AEs were reported by 3.7-12.5% of subjects depending on study group during the booster stage. The two possibly related AEs included a mild worsening of psoriasis and a severe influenza-like illness that resolved in 10 days.

INTERPRETATION

Immune responses declined after the primary vaccination series; however, a substantially greater number of subjects retained protective responses at 48 months after primary vaccination compared with subjects having protective responses before vaccination. Persistence trends were similar across all 5 study groups regardless of whether a two- or three-dose primary schedule was received. Furthermore, a booster dose given 48 months after primary vaccination was safe, well-tolerated, and elicited robust immune responses indicative of immunologic memory; these responses were similar between two- and three-dose primary schedule study groups. Use of a booster dose may help further extend protection against MenB disease in adolescents.

FUNDING

Pfizer Inc.

Clinical data supporting a 2-dose schedule of MenB-FHbp, a bivalent meningococcal serogroup B vaccine, in adolescents and young adults

Invasive meningococcal disease (IMD) caused by Neisseria meningitidis is a potentially devastating condition that can result in death and is associated with serious long-term sequelae in survivors. Vaccination is the preferred preventative strategy. Quadrivalent polysaccharide-based vaccines that protect against infection caused by meningococcal serogroups A, C, W, and Y are not effective against meningococcal serogroup B (MenB), which was responsible for approximately 60% and 35% of confirmed IMD cases in the European Union and the United States in 2016, respectively. A recombinant protein MenB vaccine (MenB-FHbp [bivalent rLP2086; Trumenba®]) has been approved for protection against MenB infection in persons 10-25 years of age in the United States and Canada and for individuals ≥10 years of age in the European Union and Australia. In these regions, MenB-FHbp is approved as a 2- or 3-dose primary vaccination schedule. This report will review the current evidence supporting administration of MenB-FHbp as a 2-dose primary vaccination schedule. Different contexts in which a 2- or 3-dose primary vaccination schedule might be preferred (eg, routine prospective vaccination vs outbreak control) are reviewed.

Vaccination strategies for the prevention of meningococcal disease

Routine prophylactic vaccination and mass vaccination strategies have been used to control both endemic and epidemic disease caused by Neisseria meningitidis globally. This review discusses real-world examples of these vaccination strategies, their implementation, and outcomes of these efforts, with the overall goal of providing insights on how to achieve optimal control of meningococcal disease through vaccination in varied settings. Tailoring immunization programs to fit the needs of the target population has the potential to optimally reduce disease incidence.

A Bivalent Meningococcal B Vaccine in Adolescents and Young Adults

BACKGROUND

MenB-FHbp is a licensed meningococcal B vaccine targeting factor H-binding protein. Two phase 3 studies assessed the safety of the vaccine and its immunogenicity against diverse strains of group B meningococcus.

METHODS

We randomly assigned 3596 adolescents (10 to 18 years of age) to receive MenB-FHbp or hepatitis A virus vaccine and saline and assigned 3304 young adults (18 to 25 years of age) to receive MenB-FHbp or saline at baseline, 2 months, and 6 months. Immunogenicity was assessed in serum bactericidal assays that included human complement (hSBAs). We used 14 meningococcal B test strains that expressed vaccine-heterologous factor H-binding proteins representative of meningococcal B epidemiologic diversity; an hSBA titer of at least 1:4 is the accepted correlate of protection. The five primary end points were the proportion of participants who had an increase in their hSBA titer for each of 4 primary strains by a factor of 4 or more and the proportion of those who had an hSBA titer at least as high as the lower limit of quantitation (1:8 or 1:16) for all 4 strains combined after dose 3. We also assessed the hSBA responses to the primary strains after dose 2; hSBA responses to the 10 additional strains after doses 2 and 3 were assessed in a subgroup of participants only. Safety was assessed in participants who received at least one dose.

RESULTS

In the modified intention-to-treat population, the percentage of adolescents who had an increase in the hSBA titer by a factor of 4 or more against each primary strain ranged from 56.0 to 85.3% after dose 2 and from 78.8 to 90.2% after dose 3; the percentages of young adults ranged from 54.6 to 85.6% and 78.9 to 89.7%, after doses 2 and 3, respectively. Composite responses after doses 2 and 3 in adolescents were 53.7% and 82.7%, respectively, and those in young adults were 63.3% and 84.5%, respectively. Responses to the 4 primary strains were predictive of responses to the 10 additional strains. Most of those who received MenB-FHbp reported mild or moderate pain at the vaccination site.

CONCLUSIONS

MenB-FHbp elicited bactericidal responses against diverse meningococcal B strains after doses 2 and 3 and was associated with more reactions at the injection site than the hepatitis A virus vaccine and saline. (Funded by Pfizer; ClinicalTrials.gov numbers, NCT01830855 and NCT01352845 ).

Meningococcal serogroup B vaccines: Estimating breadth of coverage

Neisseria meningitidis serogroup B (MenB) is an important cause of invasive meningococcal disease. The development of safe and effective vaccines with activity across the diversity of MenB strains has been challenging. While capsular polysaccharide conjugate vaccines have been highly successful in the prevention of disease due to meningococcal serogroups A, C, W, and Y, this approach has not been possible for MenB owing to the poor immunogenicity of the MenB capsular polysaccharide. Vaccines based on outer membrane vesicles have been successful in the prevention of invasive MenB disease caused by the single epidemic strain from which they were derived, but they do not confer broad protection against diverse MenB strains. Thus, alternative approaches to vaccine development have been pursued to identify vaccine antigens that can provide broad protection against the epidemiologic and antigenic diversity of invasive MenB strains. Human factor H binding protein (fHBP) was found to be such an antigen, as it is expressed on nearly all invasive disease strains of MenB and can induce bactericidal responses against diverse MenB strains. A bivalent vaccine (Trumenba®, MenB-FHbp, bivalent rLP2086) composed of equal amounts of 2 fHBP variants from each of the 2 immunologically diverse subfamilies of fHBP (subfamilies A and B) was the first MenB vaccine licensed in the United States under an accelerated approval pathway for prevention of invasive MenB disease. Due to the relatively low incidence of meningococcal disease, demonstration of vaccine efficacy for the purposes of licensure of bivalent rLP2086 was based on vaccine-elicited bactericidal activity as a surrogate marker of efficacy, as measured in vitro by the serum bactericidal assay using human complement. Because bacterial surface proteins such as fHBP are antigenically variable, an important component for evaluation and licensure of bivalent rLP2086 included stringent criteria for assessment of breadth of coverage across antigenically diverse and epidemiologically important MenB strains. This review describes the rigorous approach used to assess broad coverage of bivalent rLP2086. Alternative nonfunctional assays proposed for assessing vaccine coverage are also discussed.

Immunogenicity, Safety, and Tolerability of Bivalent rLP2086 Meningococcal Group B Vaccine Administered Concomitantly With Diphtheria, Tetanus, and Acellular Pertussis and Inactivated Poliomyelitis Vaccines to Healthy Adolescents

KEY POINTS

Concomitant administration of bivalent rLP2086 (Trumenba [Pfizer, Inc] and diphtheria, tetanus, and acellular pertussis and inactivated poliovirus vaccine (DTaP/IPV) was immunologically noninferior to DTaP/IPV and saline and was safe and well tolerated. Bivalent rLP2086 elicited robust and broad bactericidal antibody responses to diverse Neisseria meningitidis serogroup B strains expressing antigens heterologous to vaccine antigens after 2 and 3 vaccinations.

BACKGROUND

Bivalent rLP2086, a Neisseria meningitidis serogroup B (MnB) vaccine (Trumenba [Pfizer, Inc]) recently approved in the United States to prevent invasive MnB disease in individuals aged 10-25 years, contains recombinant subfamily A and B factor H binding proteins (fHBPs). This study evaluated the coadministration of Repevax (diphtheria, tetanus, and acellular pertussis and inactivated poliovirus vaccine [DTaP/IPV]) (Sanofi Pasteur MSD, Ltd) and bivalent rLP2086.

METHODS

Healthy adolescents aged ≥11 to <19 years received bivalent rLP2086 + DTaP/IPV or saline + DTaP/IPV at month 0 and bivalent rLP2086 or saline at months 2 and 6. The primary end point was the proportion of participants in whom prespecified levels of antibodies to DTaP/IPV were achieved 1 month after DTaP/IPV administration. Immune responses to bivalent rLP2086 were measured with serum bactericidal assays using human complement (hSBAs) against 4 MnB test strains expressing fHBP subfamily A or B proteins different from the vaccine antigens.

RESULTS

Participants were randomly assigned to receive bivalent rLP2086 + DTaP/IPV (n = 373) or saline + DTaP/IPV (n = 376). Immune responses to DTaP/IPV in participants who received bivalent rLP2086 + DTaP/IPV were noninferior to those in participants who received saline + DTaP/IPV.The proportions of bivalent rLP2086 + DTaP/IPV recipients with prespecified seroprotective hSBA titers to the 4 MnB test strains were 55.5%-97.3% after vaccination 2 and 81.5%-100% after vaccination 3. The administration of bivalent rLP2086 was well tolerated and resulted in few serious adverse events.

CONCLUSIONS

Immune responses to DTaP/IPV administered with bivalent rLP2086 to adolescents were noninferior to DTaP/IPV administered alone. Bivalent rLP2086 was well tolerated and elicited substantial and broad bactericidal responses to diverse MnB strains in a high proportion of recipients after 2 vaccinations, and these responses were further enhanced after 3 vaccinations.ClinicalTrials.gov identifier NCT01323270.

Meningococcal Serogroup B Bivalent rLP2086 Vaccine Elicits Broad and Robust Serum Bactericidal Responses in Healthy Adolescents

BACKGROUND

Neisseria meningitidis serogroup B (MnB) is a leading cause of invasive meningococcal disease in adolescents and young adults. A recombinant factor H binding protein (fHBP) vaccine (Trumenba(®); bivalent rLP2086) was recently approved in the United States in individuals aged 10-25 years. Immunogenicity and safety of 2- or 3-dose schedules of bivalent rLP2086 were assessed in adolescents.

METHODS

Healthy adolescents (11 to <19 years) were randomized to 1 of 5 bivalent rLP2086 dosing regimens (0,1,6-month; 0,2,6-month; 0,2-month; 0,4-month; 0,6-month). Immunogenicity was assessed by serum bactericidal antibody assay using human complement (hSBA). Safety assessments included local and systemic reactions and adverse events.

RESULTS

Bivalent rLP2086 was immunogenic when administered as 2 or 3 doses; the most robust hSBA responses occurred with 3 doses. The proportion of subjects with hSBA titers ≥1:8 after 3 doses ranged from 91.7% to 95.0%, 98.9% to 99.4%, 88.4% to 89.0%, and 86.1% to 88.5% for MnB test strains expressing vaccine--heterologous fHBP variants A22, A56, B24, and B44, respectively. After 2 doses, responses ranged from 90.8% to 93.5%, 98.4% to 100%, 69.1% to 81.1%, and 70.1% to 77.5%. Geometric mean titers (GMTs) were highest among subjects receiving 3 doses and similar between the 2- and 3-dose regimens. After 2 doses, GMTs trended numerically higher among subjects with longer intervals between the first and second dose (6 months vs 2 and 4 months). Bivalent rLP2086 was well tolerated.

CONCLUSIONS

Bivalent rLP2086 was immunogenic and well tolerated when administered in 2 or 3 doses. Three doses yielded the most robust hSBA response rates against MnB strains expressing vaccine-heterologous subfamily B fHBPs.

A phase 2 open-label safety and immunogenicity study of a meningococcal B bivalent rLP2086 vaccine in healthy adults

BACKGROUND

Neisseria meningitidis serogroup B (MnB) is a leading cause of bacterial meningitis and septicemia in adolescents and young adults. No currently licensed and available vaccine has been shown to provide broad protection against endemic MnB disease. A bivalent rLP2086 vaccine based on two factor H-binding proteins (fHBPs) has been developed to provide broad protection against MnB disease-causing strains.

METHODS

This study assessed the safety and immunogenicity of the final formulation of a bivalent rLP2086 vaccine in 60 healthy adults (18-40 years of age) receiving 120 μg doses at 0, 1, and 6 months. Safety was assessed by collecting solicited reactogenicity data and participant-reporting of adverse events. Immunogenicity was evaluated by human serum bactericidal assay (hSBA) against 5 MnB strains expressing distinct fHBP variants and fHBP-specific immunoglobulin G titre.

RESULTS

After each immunisation, local reactions such as pain at the injection site and erythema were generally mild or moderate. The most common vaccine-related adverse event was upper respiratory tract infection, which was reported by two participants. Seroprotection (hSBA titres ≥ 1:4) was achieved in 94.3% of participants against a MnB strain expressing the vaccine-homologous fHBP variant A05 and 70.0%-94.7% against MnB strains expressing the heterologous fHBP variants B02, A22, B44, and B24. Seroconversion rates (≥ 4-fold rise in hSBA titres) ranged from 70.0% to 94.7% across the five MnB test strains following the 3-dose vaccination regimen. Immunogenicity responses tended to increase upon subsequent vaccine doses.

CONCLUSIONS

Bivalent rLP2086 is a promising vaccine candidate for broad protection against MnB disease-causing strains.

Potential impact of the bivalent rLP2806 vaccine on Neisseria meningitidis carriage and invasive serogroup B disease

Asymptomatic throat carriage of Neisseria meningitidis is common in healthy individuals. In unusual cases, the bacteria become invasive, resulting in life-threatening disease. Effective meningococcal serogroup B (MnB) vaccines should provide broad protection against disease-causing strains and may confer indirect protection by impacting carriage and subsequent transmission. Factor H binding proteins (fHBPs), components of MnB vaccines in development, are classified into two immunologically distinct subfamilies (A and B). fHBP variants of MnB strains carried by adolescents are similar to those detected in infants with MnB disease. A vaccine containing subfamily A and B fHBP variants elicited bactericidal antibody responses (titers ≥ 1:4) against MnB strains expressing fHBP variants common to carriage strains and strains that cause disease in adolescents and infants in 75–100% of adolescent study subjects. This suggests that the bivalent fHBP vaccine has the potential to provide protection against invasive MnB strains and interrupt meningococcal carriage, which may also reduce infant MnB disease.

A phase 1, randomized, open-label, active-controlled trial to assess the safety of a meningococcal serogroup B bivalent rLP2086 vaccine in healthy adults

Neisseria meningitidis serogroup B (MnB) is a significant cause of invasive meningococcal disease, but no broadly protective vaccine is yet approved. We assessed the safety and immunogenicity of a bivalent MnB vaccine composed of lipidated subfamily A and B variants of recombinant LP2086 (rLP2086, also known as factor H binding protein, fHBP). Forty-eight adults, ages 18-40 y, were randomized to receive 60, 120 or 200 μg of the bivalent rLP2086 vaccine or control at 0, 2 and 6 mo. Immunogenicity was assessed by rLP2086-specific immunoglobulin G (IgG) geometric mean titers for subfamily A and B proteins. Safety was determined by laboratory assessments of blood and urine and by reporting of solicited and unsolicited adverse events (AEs). The bivalent rLP2086 vaccine elicited high IgG titers following the second and third vaccination at all dose levels. In each of the four study arms, 11 of the 12 participating subjects reported ≥ 1 AE, and no serious AEs were reported. Local and systemic reactions were mainly mild to moderate. Laboratory abnormalities (including increased sodium, decreased neutrophils, and proteinuria) were not associated with clinical events and were not considered to be related to the study vaccine. Vaccinations were generally well-tolerated. Strong IgG antibody responses and the absence of clinically significant laboratory abnormalities support further development of the bivalent rLP2086 vaccine (www.clinicaltrials.gov; identifier: NCT00879814).

Natural history of meticillin-resistant Staphylococcus aureus colonisation among residents in community long term care facilities in Spain

The spread of meticillin-resistant Staphylococcus aureus (MRSA) is a major problem for both acute care hospitals and among residents in long term care facilities (LTCFs). We performed a cohort study to assess the natural history of MRSA colonisation in LTCF residents. Two cohorts of residents (231 MRSA carriers and 196 non-carriers) were followed up for an 18 month period, with cultures of nasal and decubitus ulcers performed every six months. In the MRSA carrier cohort, 110 (47.8%) residents had persistent MRSA colonisation for six months or longer, 44 (19.0%) had transient colonisation and nine (3.9%) were intermittently colonised. No risk factors for persistent MRSA colonisation could be determined. The annual incidence of MRSA acquisition was around 20% [95% confidence interval (CI): 14.3-25.5]. Antibiotic treatment was independently associated with MRSA acquisition (odds ratio: 2.27; 95% CI: 1.05-4.88; P=0.03). Just two clones were distinguishable by pulsed-field gel electrophoresis and multilocus sequence typing: CC5-MRSA IV, which is widely disseminated in Spanish hospitals, and ST22-MRSA IV. This study adds to the knowledge of the epidemiology of MRSA in community LTCFs, which are important components of long term care in Spain.

Soluble oligomeric forms of beta-amyloid (Abeta) peptide stimulate Abeta production via astrogliosis in the rat brain

The aim of this study was to investigate the interaction between beta-amyloid (Abeta) peptide and astrogliosis in early stages of Abeta toxicity. In Wistar rats, anaesthetised with equitesine, a single microinjection of Abeta1-42 oligomers was placed into the retrosplenial cortex. Control animals were injected with Abeta42-1 peptide into the corresponding regions of cerebral cortex. Immunocytochemical analysis revealed an intense Abeta immunoreactivity (IR) at the level of Abeta1-42 injection site, increasing from the first 24 h to later (72 h) time point. Control injection showed a light staining surrounding the injection site. In Abeta oligomers-treated animals, Abeta-immunopositive product also accumulates in cortical cells, particularly in frontal and temporal cortices at an early (24 h) time point. Abeta-IR structures-like diffuse aggregates forms were also observed in hippocampus and in several cortical areas, increasing from the first 24 h to later (72 h) time point. In control animals no specific staining was seen neither in cortical cells nor in structures-like diffuse aggregates forms. Injections of Abeta oligomers also induce activation of astrocytes surrounding and infiltrating the injection site. Astrocyte activation is evidenced by morphological changes and upregulation of glial fibrillary acidic protein (GFAP). By GFAP immunoblotting we detected two immunopositive protein bands, at 50 and 48 kDa molecular mass. Confocal analysis also showed that GFAP co-localized with Abeta-IR material in a time-dependent manner. In conclusion, our results indicate that astrocyte activation might have a critical role in the mechanisms of Abeta-induced neurodegeneration, and that should be further studied as possible targets for therapeutic intervention in AD.