Pertussis Vaccine Research Articles

Prevalence of Pertactin-Deficient Bordetella pertussis Isolates, Slovenia.

In Slovenia, primary acellular pertussis vaccines (ACVs) containing pertactin (PRN) were mostly used during 1999-2016; ACVs without PRN were introduced in 2017. Among 123 Bordetella pertussis strains collected during 2002-2020, a total of 48 were PRN-deficient; 44 were collected after 2017. Changes to ACVs could increase PRN-deficient B. pertussis and infections.

Pertussis on the territory of Serbia in 2024 - challenges and opportunities for the future

Abstract Introduction Surveillance of pertussis in Serbia is passive surveillance and every 3 to 4 years an increased number of positive cases are registered in the population. The last quarter of 2023 and the first quarter of 2024 are characterized by an increased number of pertussis cases. Methods Descriptive study of cases with confirmed pertussis in the territory of the Republic of Serbia based on the evidence by the Public Health Service System of the Institute of Public Health of Serbia Results According to data from the Public Health Service System in the Republic of Serbia, a total of 1348 confirmed cases of pertussis were registered by the end of April 2024 (incidence rate 20.2 per 100,000 inhabitants). Conclusions The largest number of cases was registered in the age groups of people older than 20 years, that is, aged 10 to 14 years, while the highest age-specific incidence rate was recorded in the age group of infants younger than 12 months and in children aged 10 to 14 years. Of the total number of reported cases, 120 (8.9%) were hospitalized, with the largest number of those hospitalized being in the age group younger than 12 months (85, ie 70.8% of hospitalized cases). As for the territorial distribution, the largest number of pertussis cases in relation to the place of residence was reported from the territory of two districts, Južnobački District and the City of Belgrade, where the highest incidence rates were also registered. The postponement of timely vaccination against pertussis and the impossibility of vaccinating newborns up to 2 months of age have influenced the increase in the number of infected persons. Also, advanced PCR diagnostics during Covid and the possibility of applying PCR diagnostics in pertussis helped the timely diagnosis of pertussis. The introduction of vaccination with another dose of acellular pertussis vaccine and vaccination of pregnant women would be a desirable public health intervention to prevent pertussis infection. Key messages • Protection of the target population before starting school and at the age of 14 will contribute to stopping the occurrence of new cases of pertussis. These are public health challenges. • PCR diagnosis of pertussis influenced the timely diagnosis of this infection and the possibility of its adequate and timely treatment.

Systematic review of the literature about immunogenity and antibodies persistance of Tdap vaccination

Abstract Introduction In industrialized countries, routine use of pertussis vaccines has shifted the burden of pertussis disease from children to infants, adolescents and adults, leading to the necessity of booster doses. Materials and methods We prepared the review following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) with the aim of a) to describe the immunogenity of the main available vaccines for adolescents and adults b) to describe antibodies persistance after immunization with the main vaccines available in childhood and adults and, also, possible co-administration and c) to identify the gold standard for adolescent and adult immunizations. Results Of 6906 records identified, after removing duplicate records, 12 RCT were included (people aged 11-73): of these 7 studies had only 1 control group, 4 studies had 2 control group and 1 had 5 control group; moreover, of the 12 studies included only 2 regarding co-administration and all were about immunogenity. 9 out 12 studies had a Jadad score above 3 points and 10 out 12 meet the criteria of Cocrane Back Review Group Criteria List for Methodological Quality Assessment. Discussion and conclusions We found a limited number of good-quality RCTs investigating our object. The five component vaccines, although containing a lower dosage of antigen, are found to be more effective than one components vaccines for prevention. Evidences support the use of 5- components vaccines for booster sessions in adolescence and adulthood. Key messages • Although 3-component and 5-component vaccines contain a lower dose of antigen, they are more effective than 1-component vaccines in the prevention of diphtheria-tetanus and Bordetella pertussis. • The robustness of the data and the analytical tests support the use of vaccines with reduced antigen concentration for decennial booster sessions in adolescence and adulthood.

Routine vaccination coverage at ages 2 and 7, before, during, and after the COVID-19 pandemic: Results from the STARVAX surveillance system.

A decline in routine vaccination coverage in children has been observed after the onset of the COVID-19 pandemic, but it is unclear whether these declines were sustained over time. This analysis assessed changes in vaccination coverage at ages 2 and 7years for routinely administered vaccinations before, during, and after the COVID-19 pandemic. Vaccination coverage was measured using yearly data from the Standardized Reporting on Vaccination (STARVAX) surveillance system between December 31, 2019, and December 31, 2023. Four provinces (Alberta, Saskatchewan, Manitoba, and New Brunswick) and one territory (Yukon) produced reports from their immunization registries and provided the Public Health Agency of Canada with the numbers of vaccinated 2-year-old and 7-year-old children. Population estimates from Statistics Canada and the Yukon Bureau of Statistics were used as the denominators. There was a decline in vaccination coverage in 2023 compared to 2019. In 2-year-olds, coverage for one dose of the measles, mumps, and rubella (MMR) vaccine and four doses of the diphtheria, tetanus, and acellular pertussis (DTaP) vaccine decreased from 89.5% to 82.5% and from 79.9% to 72.1%, respectively. Among 7-year-olds, DTaP (up-to-date) and MMR (two doses) vaccination coverage decreased from 77.1% to 68.8% and 86.3% to 75.6%, respectively. These declines are of concern and suggest that health care professionals should provide parents with accurate information regarding vaccines and encourage them to have their children vaccinated and keep vaccinations up to date.

A whole-cell pertussis vaccine engineered to elicit reduced reactogenicity protects baboons against pertussis challenge.

Whole-cell pertussis (wP) vaccines introduced in the 1940s led to a dramatic reduction of pertussis incidence and are still widely used in low- and middle-income countries (LMICs) worldwide. The reactogenicity of wP vaccines resulted in reduced public acceptance, which drove the development and introduction of acellular pertussis (aP) vaccines in high-income countries in the 1990s. Increased incidence of pertussis disease has been observed in high-income countries following the introduction of aP vaccines despite near universal rates of pediatric vaccination. These increases are attributed to the reduced protection against colonization, carriage, and transmission as well as reduced duration of immunity conferred by aP vaccines relative to the wP vaccines they replaced. A reduced reactogenicity whole-cell pertussis (RRwP) vaccine was recently developed with the goal of achieving the same protection as conferred by wP vaccination but with an improved safety profile, which may benefit countries in which wP vaccines are still in routine use. In this study, we tested the RRwP vaccine in a baboon model of pertussis infection. We found that the RRwP vaccine induced comparable cellular and humoral immune responses and comparable protection following challenge relative to the wP vaccine, while significantly reducing injection-site reactogenicity.IMPORTANCEThe World Health Organization (WHO) recommended in 2015 that countries administering wP vaccines in their national vaccine programs should continue to do so, and that switching to aP vaccines for primary infant immunization should only be considered if periodic booster vaccinations and/or maternal immunization could be assured and sustained in their national immunization schedules (WHO, Vaccine 34:1423-1425, 2016, https://doi.org/10.1016/j.vaccine.2015.10.136). Due to the considerably higher cost of aP vaccines and the larger number of doses required, most LMICs continue to use wP vaccines. The development and introduction of a wP vaccine that induces fewer adverse events without sacrificing protection would significantly benefit countries in which wP vaccines are still in routine use. The results of this study indicate this desirable goal may be achievable.

Bibliometrics analysis and knowledge mapping of pertussis vaccine research: trends from 1994 to 2023.

This study aims to use bibliometric methods to explore the evolving landscape, hotspots, and emerging frontiers of pertussis vaccine research, providing deeper insights into the current research landscape and guiding future vaccine development efforts. We conducted a comprehensive search of the Web of Science Core Collection database (WoSCC) from January 1, 1994, to December 31, 2023, employing search terms related to vaccination (vacc* or immun*) and pertussis (pertussis, Whooping Cough, Bordetella pertussis, B. pertussis, Bordetella pertussis infection, or B. pertussis infection) in the Title or Author keywords fields. Bibliometrics analysis of pertussis research was performed utilizing the bibliometrix-biblioshiny package in RStudio, alongside CiteSpace and VOSviewer software. In total, 2,623 records were analyzed, comprising 89.63% (n = 2,351) original research articles and 10.37% (n = 272) review articles. The study revealed that academic research on the pertussis vaccine was growing at a rate of 4.64% per year. The United States and Canada lead in the number of publications. GlaxoSmithKline and the Centers for Disease Control & Prevention- United States emerged as leading institutions, with Halperin SA and Locht C as the most active authors. Vaccine was the most influential journal. Most studies focused on vaccine effectiveness duration, vaccination schedules for high-risk groups, and people's attitudes toward vaccination. Our analysis showed increasing interest of researchers in pertussis literature, yet current research mainly emphasized expanding vaccine coverage and optimizing strategies, neglecting new vaccine development. This emphasized the need for prioritizing novel pertussis vaccines to tackle the resurgence challenge.

Coverage with Selected Vaccines and Exemption Rates Among Children in Kindergarten - United States, 2023-24 School Year.

In the United States, states and local jurisdictions set vaccination requirements for school attendance, conditions and procedures for exemptions from these requirements, grace periods for submitting documentation, and provisional enrollment for students who need more time to be vaccinated. States annually report data to CDC on the number of children in kindergarten who meet, are exempt from, or are in the process of meeting requirements. Data reported by 49 states and the District of Columbia (DC) for the 2023-24 school year were used for national- and state-level estimates of the following measures: complete vaccination with required doses of measles, mumps, and rubella vaccine (MMR), diphtheria, tetanus, and acellular pertussis vaccine (DTaP), poliovirus vaccine (polio), and varicella vaccine (VAR); exemptions from vaccination; and school attendance while meeting requirements. The 2023-24 kindergarten class became age-eligible to complete most state-required vaccinations during the COVID-19 pandemic, after schools had returned to routine in-person learning. Compared with approximated national coverage levels across all reported vaccines for the 2019-20 (95%) and 2022-23 (93%) school years, coverage dropped below 93% for the 2023-24 school year, ranging from 92.3% for DTaP to 92.7% for MMR. Exemptions increased to 3.3%, compared with those during the 2022-23 (3.0%) and 2021-22 school years (2.6%). Coverage with MMR, DTaP, polio, and VAR decreased in 35, 32, 33, and 36 jurisdictions, respectively, compared with the 2022-23 school year. Exemptions increased in 41 jurisdictions, with 14 reporting that >5% of kindergartners had an exemption from one or more vaccine. Efforts by health departments, schools, and providers are needed to ensure that students begin school fully vaccinated.

Th1 polarization in Bordetella pertussis vaccine responses is maintained through a positive feedback loop.

Outbreaks of Bordetella pertussis (BP), the causative agent of whooping cough, continue despite broad vaccination coverage and have been increasing since vaccination switched from whole-BP (wP) to acellular BP (aP) vaccines. wP vaccination has been associated with more durable protective immunity and an induced Th1 polarized memory T cell response. Here, a multi-omics approach was applied to profile the immune response of 30 wP and 31 aP-primed individuals and identify correlates of T cell polarization before and after Tdap booster vaccination. We found that transcriptional changes indicating an interferon response on day 1 post-booster along with elevated plasma concentrations of IFN-γ and interferon-induced chemokines that peaked at day 1-3 post-booster correlated best with the Th1 polarization of the vaccine-induced memory T cell response on day 28. Our studies suggest that wP-primed individuals maintain their Th1 polarization through this early memory interferon response. This suggests that stimulating the interferon pathway during vaccination could be an effective strategy to elicit a predominant Th1 response in aP-primed individuals that protects better against infection.

A novel outer membrane vesicle adjuvant improves vaccine protection against Bordetella pertussis

Pertussis is a vaccine-preventable respiratory disease caused by the Gram negative coccobacillus Bordetella pertussis. The licensed acellular pertussis (aP) vaccines protect against disease but do not prevent bacterial colonization and transmission. Here, we developed and tested an intranasal vaccine composed of aP antigens combined with T-vant, a novel adjuvant derived from bacterial outer membrane vesicles, that elicits both mucosal and systemic immune responses. We hypothesized that immunization of mice with aP-T-vant would enhance mucosal immunity and eliminate B. pertussis in the respiratory tract. In contrast to mice immunized intramuscularly with the licensed aP vaccine, intranasal immunization with aP-T-vant eliminated bacteria in both the lung and nasopharynx. Protection was associated with IFN-gamma and IL-17-producing, non-circulating CD4 + T cells in the lung and nasopharynx, and sterilizing immunity in the nasopharynx was dependent on IL-17. Novel mucosal adjuvants, such as T-vant, warrant further investigation to enhance the efficacy of next generation pertussis vaccines.

Trends of Diphtheria–Tetanus–Pertussis and Measles Vaccine Coverage Preceding and during the COVID-19 Pandemic: An Analysis of the WHO European Region from 2000 to 2022

Available data highlights the significant impact of the COVID-19 pandemic on global vaccination trends. Despite this, comprehensive evaluations of these changes at the European level are still scarce. This study examines coverage for diphtheria, tetanus, and pertussis (DTP) and measles-containing vaccines (MCV) in the WHO European Region from 2000 to 2022. Vaccination coverage data, defined as the percentage of surviving infants who received the first and third doses of DTP (DTP1 and DTP3) and the first and second doses of MCV (MCV1 and MCV2), were extracted from UNICEF databases. Joinpoint regression analysis was employed to identify joinpoints in the time series and to estimate Annual Percent Changes (APCs) and Average Annual Percent Changes (AAPCs) over predefined timeframes. The coverages for DTP1 and MCV1 exhibit a similar trend, overall characterized by four joinpoints, one of which is in 2019. In contrast, the coverage for DTP3 does not show a significant temporal trend and lacks joinpoints, while the vaccination coverage for MCV2 shows a steadily increasing trend, with three identified joinpoints. A comparative analysis with the pre-pandemic period reveals a significant increase in the number of countries characterized by a decreasing trend during the pandemic period for all considered vaccination coverages, as indicated by the negative AAPC values. These results highlight the effect of the pandemic on childhood vaccination coverage. Compared to a mere descriptive analysis, the temporal analysis of trends using joinpoint regression provides significant opportunities to identify variations in vaccination coverages and pinpoint areas for intervention in future vaccination strategies.

Midwives’ perceptions and experiences of recommending and delivering vaccinations to pregnant women following the Covid-19 pandemic: a qualitative study

BackgroundPregnant women and their unborn babies are at an increased risk of hospitalisation, morbidity, and mortality from illness. However, uptake of influenza, pertussis and Covid-19 vaccinations offered during pregnancy is below the desired rate. This research aims to explore UK midwives’ experiences of approaching and discussing vaccinations with pregnant women, and their perceived role in pregnant women's vaccination decisions. MethodsMidwives in the West Midlands, UK were recruited via participating hospitals and midwife specific social media groups. Interviews were conducted remotely from April to July 2023 and analysed with a deductive codebook coding strategy using thematic analysis. FindingsSemi-structured interviews were conducted with 16 midwives identifying the following key themes: Recommendations to have vaccinations reported on the contents of recommendations and how they are communicated; Messages and guidance included the importance of up-to-date informational needs for midwives to administer vaccinations and the barriers caused by uncertainty and conflicting messages about the Covid-19 vaccine during pregnancy; Delivery of vaccinations included the convenience of offering vaccinations during standard antenatal appointments; and Midwives’ barriers explored the pandemic specific and other barriers midwives face in the administering of vaccinations. DiscussionThese findings contribute to the understanding of how midwives discuss the topic of vaccinations with pregnant women. This research highlights the importance for midwives to receive clear and consistent information. A strong emphasis on why vaccines are important when recommending to pregnant women in addition to standard information on the availability and timing may have a bearing in helping women to make informed decisions about accepting vaccinations.

SARS-CoV-2, Tdap, and influenza vaccination during pregnancy from 2019 to 2022 in Ontario, Canada: a population-based retrospective cohort study.

Hesitancy about vaccination during pregnancy posed challenges to SARS-CoV-2 vaccination efforts. We aimed to examine rates of SARS-CoV-2 vaccination among Ontario residents who gave birth in early 2022, and to compare rates of SARS-CoV-2 vaccine uptake with rates of tetanus, diphtheria, and pertussis (Tdap) and influenza vaccination during pregnancy in 2019, 2021, and 2022. We conducted a population-based retrospective cohort study to describe vaccination rates among pregnant and comparable nonpregnant populations in Ontario using linked administrative data. Provincially insured females who had a live, in-hospital birth from Jan. 1 to Mar. 31 in 2019, 2021, or 2022 were our primary cohort. Using log-binomial regression, we tested associations between SARS-CoV-2 (2022) and Tdap and influenza (2019, 2021, 2022) vaccination status, with birth group and covariates. We compared SARS-CoV-2 vaccination status with the status of a matched cohort of nonpregnant females and conducted subgroup analyses by age and prenatal clinician type. Among birthing people, 78.7% received their first SARS-CoV-2 vaccine dose and 74.2% received a second dose. The rate was significantly higher among nonpregnant comparators (dose 1: relative risk [RR] 0.94, 95% confidence interval [CI] 0.93-0.94; dose 2: RR 0.91, 95% CI 0.90-0.91). However, the rate of SARS-CoV-2 vaccination uptake among birthing people was higher than uptake of Tdap or influenza vaccination. Tetanus, diphtheria, and pertussis vaccination increased over time from 22.2% in 2019 to 32.6% in 2022, and influenza vaccination rose to 35.3% in 2021 but returned to prepandemic levels in 2022 (27.7%). Vaccination rates were lower among pregnant people who were young, multiparous, or residents of rural or economically deprived areas for all 3 vaccines. Rates of SARS-CoV-2 vaccination were lower among pregnant people than among nonpregnant comparators but were higher than rates of routinely recommended Tdap and influenza vaccinations. Pandemic urgency may have overcome a great deal of hesitancy about vaccinating against SARS-CoV-2 during pregnancy in 2022, but uptake of routinely recommended vaccines in pregnancy remains a challenge. Clinicaltrials.gov, no. NCT05663762.

Seroprevalence of Bordetella pertussis infection in children 1-14 years old: Indonesia basic health research (Riskesdas) 2013 and 2018 data.

Bordetella pertussis infection is a highly contagious respiratory disease that can cause complications such as pneumonia and death. A total of 62,646 cases of pertussis worldwide were reported by WHO in 2022. This study aimed to obtain the pertussis seroprevalence and sociodemographic data in children aged 1-14 years and its association factors in the community based on Riskesdas 2013 and 2018. Bivariate and multivariate analysis was carried out on data from 12,753 children aged 1-14 years collected from Riskesdas 2013 and 2018 in Indonesia. Pertussis serology data was obtained based on the results of the ELISA examination which was categorized as seropositive if anti-pertussis toxin IgG ≥ 100 IU/mL or anti-pertussis IgG > 11 NTU. Pertussis seropositive indicated recent pertussis infection if no pertussis vaccine was received within the last twelve months. Pertussis seroprevalence was found at 9.8% and 33.4% in Riskesdas 2013 and 2018 respectively. While 10.1% of children aged 5-14 years were found pertussis seropositive by excluding the possible effect of vaccination in the last twelve months in Riskesdas 2013. The most important associated factor in seropositive pertussis at ages 1-4 years and 5-14 years was a history of pneumonia in the last month (OR = 2.709, 95%CI: 2.592-2.831 in Riskesdas 2013 and OR = 2.421, 95%CI: 2.299-2.550 in Riskesdas 2018). In the adjusted analysis for respondents' characteristics, low maternal education was the predictive factor that most influenced pertussis seropositivity, especially in the 2013 Riskesdas (APOR = 2.983, 95%CI: 2.670-3.333). In conclusion, the results of this study showed that the seroprevalence of pertussis was high, especially in children aged 5-14 years, so that pertussis vaccine booster administration could be considered. Because the most influencing factor towards pertussis seropositive was low maternal education, the groups of children with low-educated mothers should be targets for strengthening complete vaccination coverage and disease control.

Incidence and severity of pertussis among hospitalized infants, Sarawak, Malaysia, 2015-2021.

A resurgence of pertussis has been reported in numerous countries. This study aimed to determine the incidence, clinical characteristics, and outcome of pertussis among infants in Sarawak, Malaysia. We conducted a descriptive retrospective study of infants aged < 12 months with laboratory-confirmed pertussis admitted to Bintulu Hospital in Sarawak, Malaysian Borneo, from 2015 until 2021. Pertussis was confirmed in all patients using a polymerase chain reaction of nasopharyngeal aspirates. Of 588 infants who had a nasopharyngeal aspirate, 108 (18%) had laboratory-confirmed pertussis. The average annual incidence was 482 per 100,000 infants aged < 12 months between 2015 and 2019, with a marked decline in 2020 and 2021. Eighty-two (76%) were < 3 months of age. Seventy-eight (72%) were unvaccinated for pertussis, including 75 (96%) who were too young to receive the first dose. A third of the cases had atypical presentations. Severe disease characterized by hypoxemia, pulmonary hypertension, recurrent apnea, encephalopathy, or cardiovascular dysfunction occurred in 32%. Forty-eight percent required humidified high-flow nasal cannula oxygen therapy and 22% required invasive ventilation. Twenty-four percent overall needed intensive care. One (1%) infant had a fatal outcome. Nearly all cases of severe disease or those that required invasive ventilation or intensive care had received ≤ 1 dose of pertussis vaccination. A high incidence of pertussis with a high rate of severe disease was observed in Sarawak, Malaysia, predominantly among infants too young to be vaccinated. Additional vaccination strategies such as maternal vaccination or cocooning should be considered.

A novel whole blood assay to quantify the release of T cell associated cytokines in response to Bordetella pertussis antigens

BackgroundBordetella pertussis continues to cause whooping cough globally even in countries with high immunisation coverage. Booster vaccinations with acellular pertussis vaccines are thus used in children, adolescents, and adults. T cell immunity is crucial for orchestrating the immune response after vaccination. However, T cell assays can be expensive and difficult to implement in large clinical trials. In this study, a whole blood (WB) stimulation assay was developed to identify secreted T cell associated cytokines in different age groups after acellular pertussis booster vaccination. Material and methodsLongitudinal WB samples were collected from a small set of subjects (n = 38) aged 7–70 years participating in a larger ongoing clinical trial. For assay development, samples were diluted and incubated with purified inactivated pertussis toxin (PT), filamentous haemagglutinin (FHA), inactivated B. pertussis lysate, and complete medium (M) as stimulating conditions, with anti-CD28 and anti-CD49d as co-stimulants. Different timepoints around the vaccination (D0, D7, D14, D28), WB dilution factor (1:2, 1:4) and incubation time (24 h, 48 h, 72 h) were compared. Responses to 15 cytokines were tested with Luminex/multiplex immunoassay. ResultsThe optimized assay consisted of WB incubation with M, PT, and FHA (including the two co-stimulants). After 48 h incubation, supernatants were collected for measurement of seven selected T cell associated cytokines (IL-2, IL-5, IL-10, IL-13, IL-17 A, IL-17F, and IFN-y) from samples before and 28 days after vaccination. PT stimulation showed a trend for upregulation of IL-2, IL-13, and IL-17 A/F for adult subjects, whereas the responses of all cytokines were downregulated for the paediatric subjects. Furthermore, PT and FHA-stimulated WB showed diverse cytokine producing profiles. ConclusionsThe developed WB-based cytokine assay was shown to be less costly, easy to perform, and functional in differently aged individuals. Further, it requires only a small amount of fresh blood, which is beneficial especially for studies including infants. Our results support the use of this assay for other immunological studies in the future.

Increased Identification of Vaccines for Vaccine Safety Surveillance Through Linkage With the Minnesota Immunization Information Connection as of December 31, 2023.

The HealthPartners' Vaccine Safety Datalink (VSD) team maintains standardized files of vaccines from medical and pharmacy claims and electronic health records (established data sources) for safety surveillance. Since 2021, for selected vaccines, data from the Minnesota Immunization Information Connection (MIIC), Minnesota's immunization information system, have been added to the HealthPartners' VSD files. We examined how MIIC data have enhanced the identification of novel and routine vaccines. We describe the approach to incorporating MIIC data. We determined and compared the number and proportion of vaccines identified from established data sources with the additional capture of vaccine data identified from MIIC, in which age group and period of observation varied by vaccine. As of December 31, 2023, of 1 099 411 people in the HealthPartners' VSD cohort, 1 001 400 people (91%) were linked with an MIIC record. Across all data sources, for the full cohort, >2.7 million COVID-19 vaccine doses were recorded since 2020, >4000 mpox vaccine doses since 2022, >7.3 million influenza vaccine doses since 2004, >600 000 human papillomavirus (HPV) vaccine doses since 2006, and >1.1 million diphtheria and tetanus toxoids and acellular pertussis (DTaP) vaccine doses since 2004. For COVID-19 vaccines, about 30% of vaccine doses were exclusively captured from MIIC, with the remaining 70% from established data sources. For the mpox vaccine, about 42% were exclusively from MIIC. For influenza, HPV, and DTaP vaccines, about 20%, 14%, and 17%, respectively, were exclusively identified from MIIC. Incorporation of data from state immunization information systems into existing vaccine data files can enhance monitoring on the safety of novel vaccines administered outside traditional health care settings and can enhance data quality for routine childhood and adult vaccines.

Vaccination Coverage by Age 24 Months Among Children Born During 2017-2021 - U.S.-Affiliated Pacific Islands.

Childhood vaccination is one of the most successful public health interventions to improve life expectancy, decrease health care costs, and reduce the spread of preventable diseases. Using data from jurisdictional immunization information systems, vaccination coverage by age 24 months among children born during 2017-2021 in the U.S.-affiliated Pacific Islands was estimated for all vaccines included in jurisdictional programs. Progress toward the U.S. Healthy People 2030 and World Health Organization Immunization Agenda 2030 vaccination goals of ≥90% coverage by age 24 months with recommended vaccines was inconsistently met across jurisdictions. For example, coverage by age 24 months with ≥1 dose of measles, mumps, and rubella vaccine ranged from 68.2% to 91.6% by birth cohort in Federated States of Micronesia and from 87.4% to 96.6% in Palau; coverage with ≥4 doses of diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP) ranged from 39.6% to 60.6% in Federated States of Micronesia and from 73.4% to 85.4% in Palau. Coverage as of June 1, 2024, increased for all vaccines across all jurisdictions and birth cohorts, indicating catch-up vaccination after age 24 months. For example, coverage with ≥4 doses of DTaP by June 1, 2024, ranged from 74.0% to 84.4% in American Samoa by birth cohort and from 91.6% to 94.8% in Palau. This report is the first comprehensive analysis of trends in childhood vaccination coverage in the U.S.-affiliated Pacific Islands; data in this report can be used to determine where additional efforts are needed to assess reasons for delayed vaccination of children and strategies to mitigate vaccination delays, specific to each jurisdiction.

Programming Bordetella pertussis lipid A to promote adjuvanticity

BackgroundBordetella pertussis is the causative agent of whooping cough or pertussis. Although both acellular (aP) and whole-cell pertussis (wP) vaccines protect against disease, the wP vaccine, which is highly reactogenic, is better at preventing colonization and transmission. Reactogenicity is mainly attributed to the lipid A moiety of B. pertussis lipooligosaccharide (LOS). Within LOS, lipid A acts as a hydrophobic anchor, engaging with TLR4-MD2 on host immune cells to initiate both MyD88-dependent and TRIF-dependent pathways, thereby influencing adaptive immune responses. Lipid A variants, such as monophosphoryl lipid A (MPLA) can also act as adjuvants. Adjuvants may overcome the shortcomings of aP vaccines.ResultsThis work used lipid A modifying enzymes from other bacteria to produce an MPLA-like adjuvant strain in B. pertussis. We created B. pertussis strains with distinct lipid A modifications, which were validated using MALDI-TOF. We engineered a hexa-acylated monophosphorylated lipid A that markedly decreased human TLR4 activation and activated the TRIF pathway. The modified lipooligosaccharide (LOS) promoted IRF3 phosphorylation and type I interferon production, similar to MPLA responses. We generated three other variants with increased adjuvanticity properties and reduced endotoxicity. Pyrogenicity studies using the Monocyte Activation Test (MAT) revealed that these four lipid A variants significantly decreased the IL-6, a marker for fever, response in peripheral blood mononuclear cells (PBMCs).ConclusionThese findings pave the way for developing wP vaccines that are possibly less reactogenic and designing adaptable adjuvants for current vaccine formulations, advancing more effective immunization strategies against pertussis.

Putting computational models of immunity to the test - an invited challenge to predict B. pertussis vaccination outcomes.

Systems vaccinology studies have been used to build computational models that predict individual vaccine responses and identify the factors contributing to differences in outcome. Comparing such models is challenging due to variability in study designs. To address this, we established a community resource to compare models predicting B. pertussis booster responses and generate experimental data for the explicit purpose of model evaluation. We here describe our second computational prediction challenge using this resource, where we benchmarked 49 algorithms from 53 scientists. We found that the most successful models stood out in their handling of nonlinearities, reducing large feature sets to representative subsets, and advanced data preprocessing. In contrast, we found that models adopted from literature that were developed to predict vaccine antibody responses in other settings performed poorly, reinforcing the need for purpose-built models. Overall, this demonstrates the value of purpose-generated datasets for rigorous and open model evaluations to identify features that improve the reliability and applicability of computational models in vaccine response prediction.

Acceptance and uptake of vaccines against tetanus, influenza, pertussis, and COVID-19 among pregnant and postpartum women in low- and middle-income countries: a systematic review and meta-analysis protocol

BackgroundPregnant women, fetuses, and neonates are particularly vulnerable to vaccine-preventable diseases (VPDs). These VPDs are associated with high morbidity and mortality among expectant mothers and their fetuses and neonates. Vaccination during pregnancy can protect the expectant mother from VPDs to which she may be especially vulnerable while pregnant. In addition, the passive transfer of maternal neutralizing immunoglobulin G (IgG) and secretory immunoglobulin A (IgA) also protects the fetus against congenital infections and may further protect the neonate from infection during the first few months of life. Despite this, coverage of recommended maternal vaccines remains suboptimal globally, especially in resource-constrained settings. Determinants of vaccine acceptance and uptake are frequently understudied in low- and middle-income countries (LMICs) and among specific groups such as pregnant and postpartum women. This proposed systematic review will assess the acceptance and uptake of vaccines against tetanus, influenza, pertussis, and COVID-19 among pregnant and postpartum women in LMICs.MethodsA Boolean search strategy employing common and medical subject heading (MeSH) terms for tetanus, influenza, pertussis, and COVID-19 vaccines, as well as vaccine acceptance, hesitancy, together with uptake, pregnancy, and postpartum, will be used to search electronic databases for relevant literature published between 2009 and 2024. Only studies conducted in LMICs that investigated determinants of acceptance, hesitancy, and uptake of tetanus, influenza, pertussis, and COVID-19 vaccines among pregnant and postpartum women will be eligible for inclusion in the review. The quality and the risk of bias of all eligible full-text articles will be assessed using the Joanna Briggs Institute’s (JBI) critical appraisal tools.DiscussionThis protocol proposes a systematic review and meta-analysis that aims to assess the uptake of maternal vaccines and to systematically appraise and quantify determinants of the acceptance and uptake of recommended vaccines during pregnancy and postpartum in LMICs. A better understanding of these factors and how they influence maternal vaccine decision-making will enable public health practitioners as well as global and national policymakers to design more effective interventions as we look towards expanding the scope and reach of maternal immunization programs.