[Factors associated with timely vaccination of pertussis-containing vaccines in children born from 2019 to 2023, Shanghai].

Objective: To analyze factors associated with timely vaccination of pertussis-containing vaccines in children born in Shanghai from 2019 to 2023. Methods: Children born in Shanghai between 2019 and 2023 were selected using a stratified random sampling method, and their vaccination data were obtained from the Shanghai Vaccine Management and Vaccination Service Information System. The vaccination rates, timely vaccination rates, and the proportions of diphtheria-tetanus-acellular pertussis-haemophilus influenzae type b combination vaccine (DTaP-Hib) and diphtheria-tetanus-acellular pertussis-inactivated poliovirus-haemophilus influenzae type b combination vaccine (DTaP-IPV-Hib) for the substitution of diphtheria- tetanus-acellular pertussis vaccine (DTaP) were calculated. Also, the factors associated with timely vaccination rate was analyzed with multivariate logistic regression analysis. Results: The average vaccination coverage rate of pertussis-containing vaccines in children born in Shanghai from 2019 to 2023 ranged from 94.71% to 99.53%. There were significant differences in the vaccination coverage of the 1st-4th doses of pertussis-containing vaccines among children born in different years (all P<0.05), but no gender and area specific significant differences were observed (all P>0.05). Non-national immunization program (non-NIP) vaccines were used to substitute DTaP vaccines in some children, with the proportion of DTaP-IPV-Hib vaccine accounting for 50.11%-52.69% and the proportion of DTaP-Hib vaccine accounting for 27.22%-28.43%. The proportions of DTaP-Hib and DTaP-IPV-Hib for the substitution of DTaP had increasing trends over the years. The overall timely vaccination rate of pertussis-containing vaccine vaccination was 84.09%. Analysis on the factors affecting the timely vaccination rate showed that the rate gradually decreased with the increase of the doses. Children who received the self-paid quadrivalent or pentavalent vaccines were less likely to have vaccination delays. Birth year had a significant impact on the timely vaccination rate, while the area had less impact. Additionally, the timely vaccination rate was also influenced by the degree of non-pharmaceutical intervention measures. Conclusions: The substitution of pertussis- containing vaccines with non-NIP vaccines was common in Shanghai. The coverage and timeliness of pertussis-containing vaccine vaccination were relatively high. The timely vaccination rate was significantly associated with gender, dose, vaccine type, and the degree of non-pharmaceutical interventions. There was a certain proportions of delayed and missed vaccinations, and it is necessary to pay attention to children who are not vaccinated timely and conduct high-quality catch-up vaccination to ensure timely and complete vaccination of pertussis-containing vaccines.

Assessing the impact of COVID-19 non-pharmaceutical interventions and relaxation policies on Class B respiratory infectious diseases transmission in China.

This study investigates the incidence of Class B respiratory infectious diseases (RIDs) in China under the Coronavirus disease 2019 (COVID-19) epidemic and examines variations post-epidemic, following the relaxation of non-pharmaceutical interventions (NPIs). Two-stage evaluation was used in our study. In the first stage evaluation, we established counterfactual models for the pre-COVID-19 period to estimate expected incidences of Class B RIDs without the onset of the epidemic. In the second stage evaluation, we constructed seasonal autoregressive integrated moving average intervention (SARIMA-Intervention) models to evaluate the impact on the Class B RIDs after NPIs aimed at COVID-19 pandemic were relaxed. The counterfactual model in the first stage evaluation suggested average annual increases of 10.015%, 78.019%, 70.439%, and 67.799% for tuberculosis, scarlet fever, measles, and pertussis respectively, had the epidemic not occurred. In the second stage evaluation, the total relative reduction in 2023 of tuberculosis, scarlet fever, measles and pertussis were - 35.209%, - 59.184%, - 4.481%, and - 9.943% respectively. The actual incidence declined significantly in the first stage evaluation. However, the results of the second stage evaluation indicated that a rebound occurred in four Class B RIDs after the relaxation of NPIs; all of these showed a negative total relative reduction rate.

Insights into maternal pertussis vaccination counselling: a qualitative study on perspectives and experiences among midwives and gynaecologists in the Netherlands.

BACKGROUND: Healthcare professionals (HCPs) play a significant role in the decision-making process of pregnant women on maternal vaccinations. Whereas a high proportion of HCPs discuss maternal vaccinations with pregnant women, confidence in discussing maternal vaccinations is lacking and HCPs experience inadequate training to discuss maternal vaccinations with pregnant women. Furthermore, different practical barriers might influence the consultation process, such as lack of time. More studies on the barriers, as well as facilitators, to discussing maternal vaccinations is needed and will help us to better understand and support HCPs in discussing maternal vaccinations. METHODS: This qualitative study involved semi-structured interviews with fourteen HCPs working as midwives or gynaecologists in the Netherlands. An integrated theoretical approach was used to inform data collection and analysis. Thematic analysis was conducted using inductive and deductive approaches. This study followed the COnsolidated criteria for REporting Qualitative research (COREQ) guidelines. RESULTS: The thematic analysis of the data pointed to the following five themes of HCP counselling: the consultation process, attitude, perceived norm, perceived control and improvement ideas. Most HCPs follow a similar approach in maternal pertussis vaccination consultations, beginning by assessing clients' understanding, providing basic information, and addressing questions. However, consultation timing and prioritization vary among HCPs. Challenges in consultations include client requests for clear advice, with HCPs trained to remain neutral, emphasizing client autonomy in decision-making. Most HCPs acknowledge the importance of their consultations in informing pregnant women about maternal pertussis vaccination. CONCLUSIONS: This study offers a confirmation of the awareness of the pivotal role of HCPs in informing pregnant women about the maternal pertussis vaccination. HCPs stress the importance of neutral counselling, enabling pregnant women to make well-informed decisions independently. Because of upcoming vaccine hesitancy nowadays, HCPs must be equipped with the knowledge and confidence to navigate difficult conversations. Continuous education and training might help to increase HCPs' confidence in handling difficult consultations. Additionally, making the information materials for pregnant women available in multiple languages and incorporating more visuals to enhance comprehension could support HCPs in reaching a broader group of pregnant women.

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.

BACKGROUND: Pregnant 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. METHODS: A 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. DISCUSSION: This 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.

Phase 1 trial of an investigational Tdap booster vaccine with CpG 1018 adjuvant compared with Boostrix in healthy adults and adolescents.

This phase 1 trial assessed the safety and immunogenicity of an investigational tetanus/diphtheria/acellular pertussis vaccine combined with CpG 1018 adjuvant 1500 µg (Tdap-1018 1500 µg) or 3000 µg (Tdap-1018 3000 µg) in adults and adolescents. In this randomized, active-controlled, multicenter, dose-escalation trial, healthy participants aged 10 to 22 years received 1 dose of Tdap-1018 1500 µg, Tdap-1018 3000 µg, or Boostrix. Geometric mean concentrations (GMCs) and booster response rates (BRRs) for antibodies against pertussis (pertussis toxin, filamentous hemagglutinin, pertactin), tetanus, and diphtheria antigens, and neutralizing antibodies against pertussis toxin were assessed 4 weeks after vaccination. Safety and tolerability were assessed for solicited post-injection reactions within 7 days after vaccination and unsolicited adverse events up to 12 weeks after vaccination. Of 117 enrolled participants, 80 adults (92%) and 30 adolescents (100%) completed the study. Both Tdap-1018 formulations were generally well tolerated, with no vaccine-related serious adverse events. Frequency and severity in post-injection reactions after Tdap-1018 administration were similar to Boostrix except for higher proportions of moderate pain for Tdap-1018. In adults at week 4, ratio of GMCs and BRRs for all antigens in the 3000-µg group were similar to or higher than Boostrix, with significantly higher GMC ratios for anti-pertussis toxin (2.1 [1.5-3.0]) and anti-tetanus (1.8 [1.1-2.9]) and significantly higher BRRs for anti-pertussis toxin (difference [95% CI]: 34.5% [13.4-54.6]), anti-pertactin (19.2% [4.4-38.1]), and anti-tetanus (30.0% [3.6-52.7]) antibodies. For adolescents, in the 3000-µg group, ratio of GMCs and BRRs were similar to or higher than Boostrix for all antigens. Both Tdap-1018 formulations showed acceptable safety and tolerability profiles. Tdap-1018 3000 µg induced similar or higher immune responses than Boostrix. ACTRN12620001177943 (Australian New Zealand Clinical Trials Registry; https://anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=ACTRN12620001177943p).

Association between real-time polymerase chain reaction cycle threshold value and clinical presentation in children with Bordetella pertussis.

BACKGROUND: The cycle threshold (Ct) value is inversely proportional to the number of copies of the target region in a sample, suggesting that a low Ct value indicates a high pathogen load. The relationship between Ct value and clinical presentation in children with pertussis is not well-defined. METHODS: We investigated the relationships between the Ct value of nasopharyngeal samples positive for Bordetella pertussis deoxyribonucleic acid via real-time polymerase chain reaction (PCR), collected from children on admission and their adult family members between May 2022 and March 2024 at Hangzhou Children's Hospital, China. The study focused on the correlation between Ct value and clinical presentation in children with pertussis. RESULTS: The Ct value was positively correlated with age (r = 0.362, P = 0.001). The mean Ct value for children with pertussis was 28.0 (range: 22.0-32.0), which was lower than the 32.0 (range: 30.0-34.0) observed in adults. Ct value was inversely correlated with length of stay, an indicator of disease severity (r = -0.356, P = 0.001). Logistic regression analyses revealed that both Ct value (OR: 0.891, 95% CI: 0.799-0.993, P = 0.036) and white blood cell count (OR: 1.127, 95% CI: 1.005-1.263, P = 0.040) were independently associated with severity of pertussis. CONCLUSIONS: Real-time PCR Ct values at initial diagnosis for pertussis may potentially predict severe disease outcomes in children.

Programming Bordetella pertussis lipid A to promote adjuvanticity.

BACKGROUND: Bordetella 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. RESULTS: This 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). CONCLUSION: These 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.

Pertussis outbreak investigation in Likimsa-Bokore kebele, Meda Walebu district, Bale zone, Oromia region, Ethiopia, 2019: a descriptive cross-sectional study.

Introduction: pertussis is a major cause of childhood morbidity and mortality. Globally, an estimated 45 millions cases and 400,000 deaths occur every year. Meda Walebu surveillance office reported a pertussis outbreak among the residents of the Liqimsa-Bokore kebele communities. We investigated to describe the magnitude of the pertussis outbreak in Likimsa-Bokore kebele of Meda-Walebu district, Bale Zone, Southeast Ethiopia. Methods: we conducted a descriptive cross-sectional study in April 2019. We identified pertussis cases recorded on the line list. Suspected cases of pertussis were defined as any resident of Likimsa-Bokore kebele with cough illness and any of the following: paroxysms of coughing, inspiratory whooping, post-tussive vomiting, or apnea. The pentavalent vaccine coverage data were extracted from the Bale zone health management information system department database. Microsoft Excel pivot table and SPSS version 23 software cleaned and analyzed the data. Results: in three months period, a total of 439 suspected cases of pertussis were reported from Likimsa-Bokore kebele of the Meda-Walebu district. Half of the cases 220(50.1%) have occurred in females and the majority of cases 256 (58.3%) occurred in under five years children. The median age of cases was 4 years ranging from 2 months to 30 years (interquartile range= 4 years). The overall Attack Rate (AR) was 55 per 1000 population with a case fatality rate of 0.7% (3 deaths/439). Children less than five years were the most affected age group with an AR of 198 per 1000 population. The administrative pentavalent vaccine coverage of the district was above 100% during the year 2015-2018. Conclusion: the overall attack rate of pertussis outbreak was high. Children under five years were the most affected age group irrespective of high administrative coverage of the pentavalent vaccine. Strengthening routine immunization management and intensified surveillance system is required for early detection, investigation, and response activities.

Global tendency and frontiers of research on pertussis from 2000 to 2023: A bibliometric and visual analysis.

Pertussis has reemerged globally, with rising incidence in China. Controlling this disease remains a significant public health challenge worldwide. This study applies bibliometric methods to analyze global and Chinese research on pertussis, assessing current trends, identifying hot topics, predicting future research directions, and providing guidance for scientific research and clinical practice. Pertussis-related articles from 2000 to 2023 were retrieved from four major Chinese databases and three English databases. COOC and CiteSpace software were used to analyze publication trends, geographic distribution, institutions, disciplines, and keywords, to visualize through network maps. The study analyzed 2,580 Chinese and 5,311 foreign articles and reviews. Pertussis research publications have increased globally, with foreign research peaking earlier than in China. The United States leads in publication volume, while China showed the highest burst of activity from 2019 to 2023. Research mainly focuses on animal experiments, vaccine development and safety, clinical characteristics and treatment, and pertussis toxin. Pertussis research is thriving globally and in China. Future research should emphasize interdisciplinary collaboration across molecular biology, immunology, and epidemiology to innovate vaccines and control strategies. Additionally, continued development of treatment drugs remains crucial as current vaccines do not fully control pertussis.

What Is Pertussis?

This JAMA Patient Page describes pertussis illness, its signs and symptoms, and its diagnosis, treatment, and prevention measures.

The Burden and Risk Factors Associated with Infectious Diseases among Refugees in a Camp for Migrants in Porto Alegre: A Cross-Sectional Survey.

Refugees usually face a disproportionate burden of infectious diseases. Recently, Brazil has experienced an influx of refugees which demands the need for scaling up public health efforts to address the challenges. The research sought to study the burden and risk factors associated with infectious diseases among refugees received in the city of Porto Alegre. This was a cross-sectional study of 261 newly arrived refugees. The study sample was predominantly composed of Venezuelans (50.6%) and Haitians (44%), male (146: 56.7%), single (30.7%), with an average age of 33.38 (± 7.30) years. The average schooling was 10.42 (± 2.09) years. Diseases with the highest prevalence were influenza, whooping cough, diphtheria, and tuberculosis. There was significant association between the country of origin and presence of symptoms for infectious and contagious diseases, which warrants targeted interventions for reducing the incidence of these diseases among refugees in Brazil.

Timing of pertussis vaccination during pregnancy: Evidence and implementation - A systematic review.

BACKGROUND: Pertussis vaccination in pregnancy has been introduced in an increasing number of countries to better protect infants against the disease in their first weeks of life. The optimal timing of pertussis vaccination in pregnancy is however still under debate. METHODS: We systematically reviewed published literature on safety, immunogenicity and effectiveness of pertussis vaccination in pregnancy related to timing of vaccination. The search was conducted using PubMed, MEDLINE and Web of Science and yielded 1623 articles, thereof 777 duplicates. Screening resulted in the inclusion of 45 publications reporting on safety (n = 11), immunogenicity (n = 26) and/or effectiveness (n = 9). We also mapped pertussis recommendations in pregnancy by government institutions globally according to the recommended timing of vaccination. RESULTS: Overall, the selected publications did not indicate increased safety concerns associated with timing of pertussis vaccination in pregnancy. Immunogenicity studies often suggested optimal protection at birth after early third trimester vaccination. Few studies investigated qualitative antibody characteristics, and none investigated antibody titers in breastmilk or cellular-mediated immunity related to timing of vaccination. Effectiveness studies showed decreased vaccine effectiveness of late third trimester pertussis vaccination compared to vaccination earlier in pregnancy. Worldwide, a general recommendation for pertussis vaccination in pregnancy was found for 58 countries, with as many as 22 different recommended timings registered. CONCLUSION: The timing of pertussis vaccination in pregnancy seems to impact immunogenicity and vaccine effectiveness, with optimal immune responses at birth suggested following early third trimester vaccination and reduced vaccine effectiveness of late third trimester pertussis vaccination suggested compared to vaccination earlier in pregnancy. However, inconsistent and lacking data are reflected in the divergent national recommendations for pertussis vaccination in pregnancy worldwide. SUMMARY: Pertussis vaccination in pregnancy aims to protect infants in their first weeks of life. Our review suggests that immunogenicity and vaccine effectiveness are impacted by the timing of vaccination in pregnancy. National recommendations for pertussis vaccination in pregnancy vary widely worldwide.

Resurgence of Bordetella pertussis, including one macrolide-resistant isolate, France, 2024.

As other European countries, France is experiencing a resurgence of pertussis in 2024. Between 1 January and 31 May 2024, 5,616 (24.9%) positive Bordetella pertussis qPCR tests were identified, following a 3-year period of almost null incidence. Of 67 cultured and whole genome sequenced B. pertussis isolates, 66 produced pertactin and 56 produced FIM2, in contrast to pre-COVID-19 years. One isolate of genotype Bp-AgST4 was resistant to macrolides. Pertussis resurgence may favour isolates that produce FIM2 and pertactin.

Comparison of in-house enzyme-linked immunosorbent assay (ELISA) and six commercial ELISAs for Detection of antibodies to Bordetella pertussis.

Enzyme-linked immunosorbent assays (ELISA) are currently the method of choice for the serodiagnosis of pertussis and play a key role in the diagnosis of pertussis in adolescents and adults, as well as in epidemiological studies. In the present study, the in-house developed indirect ELISA was comparatively evaluated with six commercial kits from various manufacturers. Antipertussis antibodies were measured in 40 serum samples from patients with clinical symptoms of respiratory tract infection, in two WHO standards, and in seven human ECDC control sera. IgA and IgG antibodies were detected at a diagnostically significant level by different ELISA kits of 5.0% to 27.0% and 12.0% to 70.0% of patients' sera, appropriately. The analysis of results carried out with six commercial kits showed only 17.5% consistent results in class IgG (either clearly positive or negative). The average percentage of errors in the level of antibodies determined in the control samples, reference serum samples, differed quite significantly and ranged from 9.5% to 35.4% depending on the kit. This poor correlation of the results obtained on various serological tests intended for the serodiagnosis of pertussis may cause very serious diagnostic problems, especially when examining a serum sample obtained once during the course of the disease.

Promotion and COVID-19 lockdown increase uptake of funded maternal pertussis vaccination in pharmacy: A mixed methods study.

Pertussis vaccination is recommended during pregnancy to protect the baby. Pertussis vaccination was initially free to pregnant people through general practice and hospitals in New Zealand, but uptake was suboptimal. In one district funding of maternal pertussis vaccination was widened to community pharmacies in 2016. Eighteen months later promotion to pharmacies, midwives and pregnant people took place. In 2020 and 2021, COVID-19 lockdowns occurred. AIM: To explore the effects of promotion and COVID-19 lockdowns on uptake of funded maternal pertussis vaccination in pharmacy, and awareness, use and opinions of promotional elements. METHODS: Five years of pharmacy claims data were analysed and 12 pharmacists, 18 people eligible/recently eligible for maternal pertussis vaccination and 11 midwives were interviewed. RESULTS: Provision of maternal pertussis vaccination increased during and after promotion. Qualitative data showed that pharmacists valued phone calls with information about maternal pertussis vaccination and recommendations for increasing uptake. Prompted by these calls, some pharmacists contacted midwives to inform them of funded maternal pertussis vaccination in the pharmacy (which midwives appreciated) and recommended pertussis vaccination to pregnant clients. Pharmacy staff reportedly were motivated to recommend this vaccination by being informed about it and having posters displayed in the pharmacy. Pregnant people valued healthcare professionals' conversations about maternal pertussis vaccination, but appeared to be uninfluenced by posters and promotional social media posts about this vaccination. During COVID-19, maternal pertussis uptake in pharmacies increased 31% March to May 2020 (before and during the first COVID-19 lockdown) versus the same time the previous year, then declined. CONCLUSION: Promotion appeared to have a sustained effect on uptake of maternal pertussis vaccination in pharmacies. Pregnant people were most influenced by discussions with healthcare professionals. Pharmacists and pharmacy staff increased proactivity with maternal vaccinations after promotion to them. Promotion may need to be repeated over time.

Pertussis vaccination in adults in France: Overview and suggestions for improvement.

In France, the goal of the pertussis vaccination program is to protect newborns. All infants are vaccinated under the program and then given booster shots up to the age of 25 years. Pregnant women are likewise vaccinated, with the cocooning strategy reserved for infants born to unvaccinated mothers. Real-world data shows (i) inadequate coverage among adolescents and adults under 25; (ii) improper use of the tetanus, diphtheria, and polio (Td/IPV) vaccine in children under six years, adolescents, and young adults; and (iii) underdiagnosis of pertussis in adults. Older patients or those with specific chronic medical conditions are at risk of developing severe disease. Improving the diagnosis and surveillance of pertussis in adults and seniors would be one of the first steps in the right direction. Aligning pertussis vaccination in adults with the Td/IPV program (boosters at 45, 65 years of age, and then every 10 years) would make the vaccination schedule simpler, easier to understand, and easier to implement. Large-scale awareness campaigns targeting this population would increase coverage, thereby boosting the effectiveness of the other measures.