Control Of Pertussis Research Articles

The long-term effects of meteorological parameters on pertussis infections in Chongqing, China, 2004\u20132018

Evidence on the long-term influence of climatic variables on pertussis is limited. This study aims to explore the long-term quantitative relationship between weather variability and pertussis. Data on the monthly number of pertussis cases and weather parameters in Chongqing in the period of 2004–2018 were collected. Then, we used a negative binomial multivariable regression model and cointegration testing to examine the association of variations in monthly meteorological parameters and pertussis. Descriptive statistics exhibited that the pertussis incidence rose from 0.251 per 100,000 people in 2004 to 3.661 per 100,000 persons in 2018, and pertussis was a seasonal illness, peaked in spring and summer. The results from the regression model that allowed for the long-term trends, seasonality, autoregression, and delayed effects after correcting for overdispersion showed that a 1 hPa increment in the delayed one-month air pressure contributed to a 3.559% (95% CI 0.746–6.293%) reduction in the monthly number of pertussis cases; a 10 mm increment in the monthly aggregate precipitation, a 1 °C increment in the monthly average temperature, and a 1 m/s increment in the monthly average wind velocity resulted in 3.641% (95% CI 0.960–6.330%), 19.496% (95% CI 2.368–39.490%), and 3.812 (95% CI 1.243–11.690)-fold increases in the monthly number of pertussis cases, respectively. The roles of the mentioned weather parameters in the transmission of pertussis were also evidenced by a sensitivity analysis. The cointegration testing suggested a significant value among variables. Climatic factors, particularly monthly temperature, precipitation, air pressure, and wind velocity, play a role in the transmission of pertussis. This finding will be of great help in understanding the epidemic trends of pertussis in the future, and weather variability should be taken into account in the prevention and control of pertussis.

Assessment of Pertussis Vaccine Protective Effectiveness in Children in the Amhara Regional State, Ethiopia.

Background Bordetella pertussis is a human pathogen which causes pertussis, or whooping cough. The diphtheria-tetanus-pertussis immunization has significantly reduced the morbidity and mortality of pertussis globally. However, higher prevalence and resurgence of pertussis cases among both vaccinated and unvaccinated people has raised questions on the effectiveness of pertussis vaccine over time. Therefore, the objective of this study was to assess the protective effectiveness of pertussis vaccine in the Amhara Regional State, Ethiopia. Methods A nested matched case-control study design approach was used with vaccinated individuals as cases and unvaccinated individuals as controls. The study was conducted from July 2018 to February 2019. Real-time (RT-) PCR assay was done to ascertain the presence of pertussis among clinically suspected patients. Bivariable and multivariable logistic regression analyses were computed to estimate the crude and adjusted odds ratios (ORs), respectively. Vaccine effectiveness was calculated as (1 − OR) × 100. Adjusted OR with 95% CI and a P value <0.05 were used to assess statistical significance. Results A total of 112 vaccinated and 223 unvaccinated controls were enrolled for the study. Of the total participants, 173/335 (51.6%) were males. The prevalence of pertussis among vaccinated was 35/112 (31.3%), whereas it was 84/223 (37.7%) among the control group. The adjusted matched vaccine protective effectiveness against B. pertussis infection following three doses of whole-cell vaccine was 25% among children aged between 6 and 9 years. Adjusted estimates of vaccine protective effectiveness for participants who had complete vaccination, stratified by time since last vaccination, were 50% at 6 years, 34% at 7 years, and 2% at 8–9 years since last vaccination. Conclusion Despite the availability and good coverage of childhood vaccination, the effectiveness of pertussis vaccine was found to be low in the Amhara region, Ethiopia. Moreover, we observed declining trends in the protective effectiveness of the vaccine after 6 years of vaccination. Thus, by considering the waning nature of immune response which is induced by whole-cell vaccine during early life, booster dose is highly recommended to optimize pertussis prevention and control strategies.

Clinical and epidemiological features of pertussis in Salvador, Brazil, 2011-2016.

Pertussis, a severe respiratory infection caused by Bordetella pertussis, is distributed globally. Vaccination has been crucial to annual reductions in the number of cases. However, disease reemergence has occurred over the last decade in several countries, including Brazil. Here we describe the clinical and epidemiological aspects of suspected pertussis cases in Salvador, Brazil, and evaluate factors associated with case confirmation. This descriptive and retrospective study was conducted in the five hospitals in Salvador that reported the highest number of pertussis cases between 2011–2016. Demographic and clinical data were recorded for each patient. Bivariate analysis was performed to evaluate differences between groups (confirmed vs. unconfirmed cases) using Pearson’s Chi-square test or Fisher’s exact test. Results: Of 529 suspected pertussis cases, 29.7% (157/529) were confirmed by clinical, clinical-epidemiological or laboratory criteria, with clinical criteria most frequently applied (63.7%; 100/157). Unvaccinated individuals (43.3%; 68/157) were the most affected, followed by age groups 2–3 months (37.6%; 59/157) and <2 months (31.2%; 49/157). Overall, ≤50% of the confirmed cases presented a complete vaccination schedule. All investigated cases presented cough in association with one or more symptoms, especially paroxysmal cough (66.9%; 105/529) (p = 0.001) or cyanosis (66.2%; 104/529) (p<0.001). Our results indicate that pertussis occurred mainly in infants and unvaccinated individuals in Salvador, Brazil. The predominance of clinical criteria used to confirm suspected cases highlights the need for improvement in the laboratory tools used to perform rapid diagnosis. Fluctuations in infection prevalence demonstrate the importance of vaccination strategies in improving the control and prevention of pertussis.

Pertussis in Italy: maternal immunization to protect infants

Abstract Background Despite effective pertussis vaccines and high rates of pediatric vaccination in Italy, the number of reported pertussis cases has steadily increased. To minimize severe illness and deaths, particularly in infants, in addition to active immunization, maternal vaccination has been nationally recommended. To support this prevention measure, this study sought to gain more insight into the current pertussis burden among hospitalized infants. Methods A retrospective observational study investigating infant hospitalizations for pertussis within the first year of life from 2007 to 2018 in Italy was carried out using the Hospital Discharge Database as informational flow. Four age groups were analyzed (&amp;lt;3, 3-4, 5-10, and 11-12 months), according to the expected age for the dose administration of the primary course of pertussis vaccination. The temporal trend of hospitalization rates was analyzed by the slope of the regression line. p &amp;lt; 0.05 was the criterion for statistical significance. Results There were 4262 pertussis-related admissions among infants less than 12 months of age. Overall, 61.10% were infants aged &amp;lt;3 months. The overall hospitalization rate was 69 x 100000 infants. When stratified by age, infants &amp;lt;3 months old had the highest hospitalization rate at 169 x 100000 infants, with an increasing trend (β = 9.12, p = 0.002); for the other age groups, the trend increased less strongly or was substantially stable. Conclusions This nationwide study highlighted that most of the pertussis admissions in Italy occurred in the first few months of life, before infants had started the primary vaccination course. This result indicates that more needs to be done to protect young infants (&amp;lt;3 months) who are the most vulnerable to severe disease. The implementation of maternal immunization programs could offer the hope of much better pertussis control in infants too young to be vaccinated. Key messages Infants aged &amp;lt;3 months showed the highest rates of hospitalization for pertussis, with an increasing trend. The implementation of maternal immunization programs could protect these high-risk infants.

The burden of laboratory-confirmed pertussis in low- and middle-income countries since the inception of the Expanded Programme on Immunisation (EPI) in 1974: a systematic review and meta-analysis

BackgroundAn effective vaccine against Bordetella pertussis was introduced into the Expanded Programme on Immunisation (EPI) by WHO in 1974, leading to a substantial global reduction in pertussis morbidity and mortality. In low- and middle-income countries (LMICs), however, the epidemiology of pertussis remains largely unknown. This impacts negatively on pertussis control strategies in these countries. This study aimed to systematically and comprehensively review published literature on the burden of laboratory-confirmed pertussis in LMICs over the 45 years of EPI.MethodsElectronic databases were searched for relevant literature (1974 to December 2018) using common and MeSH terms for pertussis. Studies using PCR, culture or paired serology to confirm Bordetella pertussis and parapertussis in symptomatic individuals were included if they had clearly defined numerators and denominators to determine prevalence and mortality rates.ResultsEighty-two studies (49,167 participants) made the inclusion criteria. All six WHO regions were represented with most of the studies published after 2010 and involving mainly upper middle-income countries (n = 63; 77%). PCR was the main diagnostic test after the year 2000.The overall median point prevalence of PCR-confirmed Bordetella pertussis was 11% (interquartile range (IQR), 5–27%), while culture-confirmed was 3% (IQR 1–9%) and paired serology a median of 17% (IQR 3–23%) over the period. On average, culture underestimated prevalence by 85% (RR = 0.15, 95% CI, 0.10–0.22) compared to PCR in the same studies.Risk of pertussis increased with HIV exposure [RR, 1.4 (95% CI, 1.0–2.0)] and infection [RR, 2.4 (95% CI, 1.1–5.1)]. HIV infection and exposure were also related to higher pertussis incidences, higher rates of hospitalisation and pertussis-related deaths.Pertussis mortality and case fatality rates were 0.8% (95% CI, 0.4–1.4%) and 6.5% (95% CI, 4.0–9.5%), respectively. Most deaths occurred in infants less than 6 months of age.ConclusionsDespite the widespread use of pertussis vaccines, the prevalence of pertussis remains high in LMIC over the last three decades. There is a need to increase access to PCR-based diagnostic confirmation in order to improve surveillance. Disease control measures in LMICs must take into account the persistent significant infant mortality and increased disease burden associated with HIV infection and exposure.

Dose-dependent effectiveness of acellular pertussis vaccine in infants: A population-based case-control study

BackgroundPertussis is a vaccine-preventable disease which is most severe in young infants. More than two decades after the introduction of acelluar pertussis vaccines (aPV) in national immunization programs in many countries worldwide, a resurgence of pertussis has been recognized. Suboptimal effectiveness of aPV has been blamed as one major reason but only few studies have evaluated dose-dependent vaccine effectiveness (VE) provided by aPV in current practice. MethodsWe performed a population-based retrospective case-control study by comparing pertussis immunization data of children 2.5 months to 2 years of age hospitalized for pertussis and residing in Switzerland with immunization data of a random control sample of children aged 2 years and residing in Switzerland. VE was defined as the percentage of hospitalizations avoided by number of aPV doses. It was calculated as 1-infection rate ratio (IRR)*100. IRR was calculated by dividing infection rates of vaccinated children and infection rates of unvaccinated children. To get dose specific VE,infection rates were stratified by number doses received. ResultsVE against hospitalization due to pertussis increased significantly with each consecutive aPV dose in a “3 + 1” primary course in infants: 42.1% (95% CI: 11.3–62.6), 83.9% (70.2–92.1), 98.2% (96.1–99.3), and 100% (97.9–100) after the 1st, 2nd, 3rd, and 4th dose, respectively. ConclusionAcellular pertussis vaccines continue to demonstrate protection against hospitalization due to pertussis in infants and young children. Therefore, together with advancing immunization of pregnant women and household contacts, better control of severe pertussis in young infants can be achieved by timely initiation of immunization.

Challenges to Pertussis Control.

* Abbreviations: DTaP — : diphtheria-tetanus-acellular pertussis DTwP — : diphtheria, tetanus toxoids, and whole-cell pertussis KPNC — : Kaiser Permanente Northern California In this issue of Pediatrics , the vaccine research group at Kaiser Permanente Northern California (KPNC) contributed another important article outlining the challenges of pertussis control in a highly vaccinated population.1 Nearly one-half million children born between 1999 and 2016 and managed at KPNC from 2006 to 2017 were evaluated. Of those immunized children, all had received only diphtheria-tetanus-acellular pertussis (DTaP) vaccine. In total, 738 polymerase chain reaction–confirmed pertussis cases were diagnosed. Pertussis risk was 13 times higher among unvaccinated and nearly 2 times higher among undervaccinated children when compared with those who were fully vaccinated. However, >80% of the total pertussis cases were seen in children who had received all their recommended DTaP vaccine doses. Pertussis risk increased with increasing time since vaccination, clearly demonstrating waning immunity, which the KPNC group and others had previously reported.2,3 Those individuals who began their medical career after 1997, when DTaP totally replaced the conventional diphtheria, tetanus toxoids, and whole-cell pertussis (DTwP) vaccines, may question why DTaP replaced DTwP in the first place. When I began my academic career at Vanderbilt University School of Medicine in 1980, pertussis disease appeared to be well controlled.4 Rarely would cases present to the medical center, and generally … Address correspondence to Kathryn M. Edwards, MD, Division of Infectious Diseases, Department of Pediatrics, Vanderbilt University School of Medicine, 1161 21st Ave South, D-7227 Medical Center North, Nashville, TN 37232. E-mail: kathryn.edwards{at}vumc.org

Assessment of humoral and cell-mediated immune responses to pertussis vaccination: a systematic review protocol

IntroductionGlobally, some studies show a resurgence of pertussis. The risks and benefits of using whole-cell pertussis (wP) or acellular pertussis (aP) vaccines in the control of the disease have been...

The Role of Mucosal Immunity in Pertussis.

Pertussis or whooping cough, mainly caused by Bordetella pertussis, is a severe respiratory disease that can affect all age groups but is most severe and can be life-threatening in young children. Vaccines against this disease are widely available since the 1950s. Despite high global vaccination coverage, the disease is not under control in any country, and its incidence is even increasing in several parts of the world. Epidemiological and experimental evidence has shown that the vaccines fail to prevent B. pertussis infection and transmission, although they are very effective in preventing disease. Given the high infection rate of B. pertussis, effective control of the disease likely requires prevention of infection and transmission in addition to protection against disease. With rare exceptions B. pertussis infections are restricted to the airways and do not usually disseminate beyond the respiratory epithelium. Therefore, protection at the level of the respiratory mucosa may be helpful for an improved control of pertussis. Yet, compared to systemic responses, mucosal immune responses have attracted relatively little attention in the context of pertussis vaccine development. In this review we summarize the available literature on the role of mucosal immunity in the prevention of B. pertussis infection. In contrast to vaccination, natural infection in humans and experimental infections in animals induce strong secretory IgA responses in the naso-pharynx and in the lungs. Several studies have shown that secretory IgA may be instrumental in the control of B. pertussis infection. Furthermore, studies in mouse models have revealed that B. pertussis infection, but not immunization with current acellular pertussis vaccines induces resident memory T cells, which may also contribute to protection against colonization by B. pertussis. As these resident memory T cells are long lived, vaccines that are able to induce them should provide long-lasting immunity. As of today, only one vaccine designed to induce potent mucosal immunity is in clinical development. This vaccine is a live attenuated B. pertussis strain delivered nasally in order to mimic the natural route of infection. Due to its ability to induce mucosal immunity it is expected that this approach will contribute to improved control of pertussis.

Clinical Findings and Management of Pertussis.

Pertussis is an endemic highly infectious vaccine-preventable disease. The disease is a major cause of childhood morbidity and mortality. In the most recent years, the re-emergence of pertussis occurred, and many efforts were done to identify the possible causes. Certainly, more effective laboratory methods have a role in making the diagnosis easier. However, sub-optimal efficacy of available vaccines as well as their limited duration of protection could explain the resurgence of the disease. Many forms and clinical features of the disease, ranging from the most classical to atypical and very nuanced forms, have been reported. There are many aspects that influence the clinical features of the pathology, such as a previous immunization or infection, patient's age, gender and antibiotic treatment. A prompt suspect and a rapid diagnosis of pertussis is fundamental for an appropriate clinical management and for preventing pertussis complications, especially in children. However, under a clinical point of view, pertussis is often difficult to be diagnosed. A prompt treatment may decrease the duration and severity of cough; the cornerstone drugs are the macrolides. Although prompt diagnosis and effective therapy are important for pertussis control, only with a broad vaccination coverage will be possible to reduce circulation of Bordetella pertussis.

Increasing FIM2/3 antigen-content improves efficacy of Bordetella pertussis vaccines in mice in vivo without altering vaccine-induced human reactogenicity biomarkers in vitro

Current acellular-pertussis (aP) vaccines appear inadequate for long-term pertussis control because of short-lived efficacy and the increasing prevalence of pertactin-negative isolates which may negatively impact vaccine efficacy. In this study, we added fimbriae (FIM)2 and FIM3 protein to licensed 2-, 3- or 5-component aP vaccines (Pentavac®, Boostrix®, Adacel®, respectively) to assess whether an aP vaccine with enhanced FIM content demonstrates enhanced efficacy. Vaccine-induced protection was assessed in an intranasal mouse challenge model. In addition, potential reactogenicity was measured by biomarkers in a human whole blood assay (WBA) in vitro and benchmarked the responses against licensed whole cell pertussis (wP) and aP vaccines including Easyfive®, Pentavac® and Pentacel®. The results show that commercial vaccines demonstrated reduced efficacy against pertactin-negative versus pertactin-positive strains. However, addition of higher amounts of FIM2/3 to aP vaccines reduced lung colonization and increased vaccine efficacy against a pertactin-negative strain in a dose-dependent manner. Improvements in efficacy were similar for FIM2 and FIM3-expressing strains. Increasing the amount of FIM2/3 proteins in aP formulations did not alter vaccine-induced biomarkers of potential reactogenicity including prostaglandin E2, cytokines and chemokines in human newborn cord and adult peripheral blood tested in vitro. These results suggest that increasing the quantity of FIM proteins in current pertussis vaccine formulations may further enhance vaccine efficacy against B. pertussis infection without increasing the reactogenicity of the vaccine.

Monitoring public interest toward pertussis outbreaks: an extensive Google Trends–based analysis

Pertussis is a vaccine-preventable disease. Despite this, it remains a major health problem among children in developing countries and in recent years, has re-emerged and has led to considerable outbreaks. Pertussis surveillance is of paramount importance; however, classical monitoring approaches are plagued by some shortcomings, such as considerable time delay and potential underestimation/underreporting of cases. This study aims at investigating the possibility of using Google Trends (GT) as an instrument for tracking pertussis outbreaks to see if infodemiology and infoveillance approaches could overcome the previously mentioned issues because they are based on real-time monitoring and tracking of web-related activities. In the present study, GT was mined from inception (01 January 2004) to 31 December 2015 in the different European countries. Pertussis was searched using the 'search topic' strategy. Pertussis-related GT figures were correlated with the number of pertussis cases and deaths retrieved from the European Centre for Disease prevention and Control database. At the European countries level, correlation between pertussis cases and GT-based search volumes was very large (ranging from 0.94 to 0.97) from 2004 to 2015. When examining each country, however, only a few reached the threshold of statistical significance. GT could be particularly useful in pertussis surveillance and control, provided that the algorithm is better adjusted and refined at the country level.

Prevention of pertussis: from clinical trials to Real World Evidence.

SummaryPertussis, a highly contagious infective disease caused by Bordetella pertussis, was in the past very common among newborns and children, causing significant medical, social and economic issues burden, also due to frequent need of hospitalization and high mortality. Following the introduction of vaccines against pertussis, the burden of the disease dramatically decreased, although nowadays, this disease it is still the most widespread among the vaccine preventable ones. First vaccine formulations were composed with whole cell antigen of Bordetella pertussis and were followed by formulations with acellular antigens (PT, FHA, PRN, FIM), that showed to have similar efficacy and less reactogenicity. In particular, all the acellular vaccines, regardless the number of antigenic component included, demonstrated good immunogenicity in clinical trials and high effectiveness in real world evidence studies. Nevertheless, in the recent years it has been notified an increasing number of cases of pertussis.The most recent evidence demonstrated that for an effective control and prevention of pertussis it is necessary to strengthen vaccination coverage among the whole population, providing primary vaccination to newborns and booster in infancy, adolescence and adulthood every 10 years. Finally, vaccination of women at the third trimester of every pregnancy is the most effective intervention to protect the newborn from pertussis in his first months of life, before developing a protective response after the primary vaccination.

The Epidemiology of Nationally Reported Pertussis in the United States, 2000-2016.

Despite successful vaccination programs, pertussis remains endemic in the United States, and increasing incidence has been reported. We used national surveillance data to describe pertussis epidemiology, including patient demographic characteristics, geographic distribution, and temporal trends. We included cases reported through the National Notifiable Diseases Surveillance System between 1 January 2000 and 31 December 2016. Differences in case characteristics were compared using Pearson χ2. Average annual incidence (cases per 100 000 population) was calculated overall and by age (<1 year, 1-6 years, 7-10 years, 11-18 years, 19-39 years, 30-64 years, and ≥65 years) and geographic subgroup. Annual percent change was estimated using negative bionomial regression. During 2000-2016, 339 420 pertussis cases were reported. The majority were in white (88.2%) and non-Hispanic (81.3%) persons, 9.9% were hospitalized, and 0.1% were fatal; however, differences existed by age. Infants had the highest incidence (75.3/100 000 population), accounting for 88.8% of deaths. Incidence increased significantly over time (P = .0019), increases were observed for all groups except persons aged <1 year and 19-64 years. Elevated case counts among persons aged 7-10 and 11-18 years coincided with the aging of acellular-primed cohorts. Incidence varied by geographic region, with some similarities in disease cyclicity. Increasing baseline incidence and changing age distribution of pertussis suggest a central role of the transition to acellular vaccines in the US disease resurgence. Continued monitoring of national data is important to evaluate and optimize pertussis prevention and control strategies.

Under-reporting of pertussis in Ontario: A Canadian Immunization Research Network (CIRN) study using capture-recapture.

IntroductionUnder-reporting of pertussis cases is a longstanding challenge. We estimated the true number of pertussis cases in Ontario using multiple data sources, and evaluated the completeness of each source.MethodsWe linked data from multiple sources for the period 2009 to 2015: public health reportable disease surveillance data, public health laboratory data, and health administrative data (hospitalizations, emergency department visits, and physician office visits). To estimate the total number of pertussis cases in Ontario, we used a three-source capture-recapture analysis stratified by age (infants, or aged one year and older) and adjusting for dependency between sources. We used the Bayesian Information Criterion to compare models.ResultsUsing probable and confirmed reported cases, laboratory data, and combined hospitalizations/emergency department visits, the estimated total number of cases during the six-year period amongst infants was 924, compared with 545 unique observed cases from all sources. Using the same sources, the estimated total for those aged 1 year and older was 12,883, compared with 3,304 observed cases from all sources. Only 37% of infants and 11% for those aged 1 year and over admitted to hospital or seen in an emergency department for pertussis were reported to public health. Public health reporting sensitivity varied from 2% to 68% depending on age group and the combination of data sources included. Sensitivity of combined hospitalizations and emergency department visits varied from 37% to 49% and of laboratory data from 1% to 50%.ConclusionsAll data sources contribute cases and are complementary, suggesting that the incidence of pertussis is substantially higher than suggested by routine reports. The sensitivity of different data sources varies. Better case identification is required to improve pertussis control in Ontario.

Prevention of Pertussis, Tetanus, and Diphtheria with Vaccines in the United States: Recommendations of the Advisory Committee on Immunization Practices (ACIP).

SummaryThis report compiles and summarizes all recommendations from CDC's Advisory Committee on Immunization Practices (ACIP) regarding prevention and control of tetanus, diphtheria, and pertussis in the United States. As a comprehensive summary of previously published recommendations, this report does not contain any new recommendations and replaces all previously published reports and policy notes; it is intended for use by clinicians and public health providers as a resource. ACIP recommends routine vaccination for tetanus, diphtheria, and pertussis. Infants and young children are recommended to receive a 5-dose series of diphtheria and tetanus toxoids and acellular pertussis (DTaP) vaccines, with one adolescent booster dose of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine. Adults who have never received Tdap also are recommended to receive a booster dose of Tdap. Women are recommended to receive a dose of Tdap during each pregnancy, which should be administered from 27 through 36 weeks’ gestation, regardless of previous receipt of Tdap. After receipt of Tdap, adolescents and adults are recommended to receive a booster tetanus and diphtheria toxoids (Td) vaccine every 10 years to assure ongoing protection against tetanus and diphtheria.

Investigation of the Cellular Immune Response to Recombinant Fragments of Filamentous Hemagglutinin and Pertactin of Bordetella pertussis in BALB/c Mice.

Vaccination with whole-cell or acellular (Ac) vaccines has been very effective for the control of pertussis. The immune response to Ac vaccines has been generally associated with a shift toward the Th2 profile. In the present study, overlapping recombinant fragments of filamentous hemagglutinin (FHA) and pertactin (PRN) were produced in Escherichia coli. BALB/c mice were immunized with recombinant FHA and PRN together with the native pertussis toxin and alum or CpG as adjuvant. Immunized mice were subsequently aerosol challenged with Bordetella pertussis. Bacterial growth was assessed in bronchoalveolar lavage samples and the levels of cytokines were quantitated in supernatants of stimulated splenocytes by enzyme-linked immunosorbent assay. Our results demonstrated that both PRN and FHA antigens were able to induce IFN-γ, IL-4, and to some extent IL-17 cytokines in challenged mice. The level of IFN-γ was higher in response to CpG formulated antigens. These findings indicate immunoprotective efficacy of our recombinant FHA and PRN antigens in mice.

Strategic Approaches Towards Pertussis Control in Oman.

Pertussis is a highly contagious disease that causes severe and serious symptoms among infants and young children with fatalities observed in early infancy. The disease is milder among adolescents and adults. In this paper, we describe the progress made towards pertussis control in Oman and the challenges ahead to achieve control and maintain it. Pertussis data were collected between 1981 and 2015 from various sources including Annual Health Reports, annual Ministry of Health progress reports, and Community Health and Diseases Surveillance Newsletter, which provided information for the calculation of different pertussis indicators. Diphtheria-tetanus-whole cell pertussis 3 (DTwP3) vaccination coverage rose from 19% in 1981 to 97% in 1992 and has been at 3 97% until 2015. The overall incidence of pertussis dropped dramatically from an average of 771 cases per 100 000 population from 1981 through 1985, to 21 cases per 100 000 population between 2011 and 2015 (p < 0.001). Since 1987, pertussis cases were cyclical, with peaks every three to five years with three major outbreaks reported in some parts of the country. Between 2011 and 2015, 831 cases were notified of which 785 (94.4%) met the pertussis case definition. Of these 785 cases, 625 (79.7%) were in children aged < 12 months (average rate 185 per 100 000 population), and almost all were hospitalized. Of the 625, 357 (57.1%) were aged < 2 months (average incidence of 600/100 000 population), 129 (20.6%) were 2-3 months old (average incidence of 202/100 000 population), 80 (12.8%) were 4-6 months (average incidence of 119/100 000 population), and 59 (9.4%) were 6-12 months old (average incidence is 22/100 000 population). There were 160/785 (20.3%) cases reported in children 3 12 months old (average rate 4/100 000 population). Downward trend rates were reported in the 5-14 year age group and a very low disease rate was observed in the > 15 years group. Since 2007, no deaths recorded were attributed to pertussis. Oman has a high coverage of DTP3; however, pertussis control remains a challenge among infants < 12 months old. Therefore, tetanus, diphtheria, and acellular pertussis (Tdap) vaccination of pregnant women is likely to be the best strategy for preventing the disease in infants.

Public health measures for pertussis prevention and control

Australian and New Zealand Journal of Public HealthVolume 41, Issue 6 p. 557-560 Commentary Open Access Public health measures for pertussis prevention and control Tom Kovitwanichkanont, Corresponding Author tom.kovitwanichkanont@gmail.com The University of Sydney, New South WalesCorrespondence to: Dr Tom Kovitwanichkanont, The University of Sydney, New South Wales 2006; e-mail: tom.kovitwanichkanont@gmail.comSearch for more papers by this author Tom Kovitwanichkanont, Corresponding Author tom.kovitwanichkanont@gmail.com The University of Sydney, New South WalesCorrespondence to: Dr Tom Kovitwanichkanont, The University of Sydney, New South Wales 2006; e-mail: tom.kovitwanichkanont@gmail.comSearch for more papers by this author First published: 18 October 2017 https://doi.org/10.1111/1753-6405.12732Citations: 3 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat Citing Literature Volume41, Issue6December 2017Pages 557-560 RelatedInformation

Will we have new pertussis vaccines?

Despite wide vaccination coverage with efficacious vaccines, pertussis is still not under control in any country. Two types of vaccines are available for the primary vaccination series, diphtheria/tetanus/whole-cell pertussis and diphtheria/tetanus/acellular pertussis vaccines, in addition to reduced antigen content vaccines recommended for booster vaccination. Using these vaccines, several strategies are being explored to counter the current pertussis problems, including repeated vaccination, cocoon vaccination and maternal immunization. With the exception of the latter, none have proven their effectiveness, and even maternal vaccination is not expected to ultimately control pertussis. Therefore, new pertussis vaccines are needed, and several candidates are in early pre-clinical development. They include whole-cell vaccines with low endotoxin content, outer membrane vesicles, new formulations, acellular vaccines with new adjuvants or additional antigens and live attenuated vaccines. The most advanced is the live attenuated nasal vaccine BPZE1. It provides strong protection in mice and non-human primates, is safe, even in immune compromised animals, and genetically stable after in vitro and in vivo passages. It also has interesting immunoregulatory properties without being immunosuppressive. It has successfully completed a first-in-man clinical trial, where it was found to be safe, able to transiently colonize the human respiratory tract and to induce immune responses in the colonized subjects. It is now undergoing further clinical development. As it is designed to reduce carriage and transmission of Bordetella pertussis, it may hopefully contribute to the ultimate control of pertussis.