Antibody Levels and Infection Status of Pertussis in the Population under Pertussis Resurgence in Guangxi in 2018:A Cross-Sectional Survey

Objective Pertussis cases have increased markedly since 2018 in Guangxi.The aim of this study was to evaluate antibody levels and the infection status of pertussis in the resident population.Method A total of 10,215 serum samples from residents were collected from August-November 2018 and tested for anti-pertussis IgG and toxin IgG using the enzyme-linked immunosorbent assay(ELISA).Results Of the collected samples,1,833(17.94%)tested positive for anti-pertussis IgG,with the median concentration of 16.06 IU/mL.Antibody level<10 IU/mL accounted for more than 60%in children under 4 years of age,but declined with age,whereas the percentages of the other three levels(10-40,40-50,and≥50 IU/mL)increased almost with age(P<0.001).Moreover,7,924 samples were selected for anti-pertussis toxin IgG,of which 653(8.24%)tested positive(≥40 IU/mL)with the median concentration of 5.89 IU/mL,and 204 participants(2.56%)had recent pertussis infection(≥100 IU/mL).Among the different age groups,the highest rates of positivity and recent infection were observed at 11-20 years of age,the lowest positivity rate at 5 years of age,and the lowest recent infection rate at 4 years of age(P<0.001,P=0.005,respectively).Conclusion The survey results showed that all age groups in Guangxi lacked immunity against pertussis,which was one of the main factors contributing to the resurgence of pertussis in 2018.In addition,the prevalence of pertussis is relatively high in Guangxi,and its incidence is seriously underestimated,especially in adolescents and adults.

The First Reported Case of Co-Infection with Neisseria Meningitidis and Bordetella Pertussis in the Cerebrospinal Fluid Specimen of a Normal Four-Year-Old Child

Pertussis is an acute and highly contagious respiratory disease caused by Bordetella pertussis(B.pertussis),which occurs in people of all ages and is most dangerous for young children,especially infants.The introduction of whole-cell pertussis vaccines(wPVs)in the 1950s dramatically reduced the incidence of pertussis worldwide[1].However,over the past two decades,many studies have reported the resurgence of pertussis in different countries[2].Epidemiological surveillance in Hubei Province over the last 3 years revealed a clear increasing trend in the incidence of pertussis during the coronavirus disease 2019(COVID-19)epidemic.

Risk factors for pertussis among children hospitalized for pertussis during 2016-2017, in Guizhou Province of China: a case-control study

Aim:Pertussis is a respiratory tract infection,the vaccine for which was introduced in the Expanded Programme on Immunization(EPI)in Guizhou Province of China(hereafter referred as Guizhou)in the 1980s.This vaccine rapidly decreased incidence rates of pertussis in the province,however,despite the wide high coverage of the diphtheria,tetanus and acellular pertussis(DTaP)combined vaccine,there has been a resurgence of pertussis since 2014.Even with this recent increase in disease transmission,risk factors for pertussis infection have not been evaluated in Guizhou.We aimed to provide information on pertussis risk factors and insight on designing targeted pertussis control policies and measures through this study.Methods:A 1:2 matched retrospective case-control study was conducted between 2016 and 2017,involving infants and children younger than 6 years old and parents of the participants.The enrolled cases included clinical and laboratory confirmed pertussis cases according to the WHO-recommended pertussis definition.Controls were selected from children in the same neighborhood who were not diagnosed with pertussis prior to our investigation and did not exhibit any clinical manifestations of pertussis.Results:The household size[Matched odds ratio(OR_(m)=1.4,95%confidence interval(Cl):1.1-1.7]and household members with antecedent cough(OR_(m)=3.6,95%CI:1.8-7.2)were significantly associated with their child’s pertussis onset.The parents’occupations were significantly associated with their child’s pertussis onset(ORm=9.4,95%CI:1.6-54.8,for mother side;ORm=4.5,95%CI:1.2-16.5,for father side),when they worked in the business and/or service industry.Having family members with a history of cough was an independent risk factor for pertussis[Adjusted odds ratio(AOR)=43.6,95%CI:2.7-694.0].Besides,the parents’demographic characteristics and DTaP doses were not found to be independent factors.Conclusion:Household exposure is an important risk factor for pertussis infection in infants and young children and should therefore be considered as a major factor during formulation of pertussis control policies and measures.

Epidemiological Characteristics and Risk Factors of the Pertussis in Infants < 12 Months of Age in Tianjin, China

The epidemiologic characteristics of 631 infant pertussis cases 〈 12 months, which accounted for 57.42% of the total cases, were analyzed by descriptive epidemiology in Tianjin, between 2010 and 2015. The incidence of infants was 104.66/100,000, which was 118 times higher than in other age groups （P 〈 0.001）. The primary type of pertussis simultaneously presented in households was adult-to-infant （70.51%）. The parents were identified as the source of infection in 80.18% of cases for infants. The positive rate of placental antibody transfer was 31.06% and 3.13% for 3-month-old infants. Infants presented the highest age-specific pertussis incidence. The most important reason was parents were the important sources of infection, and secondly the lower level of antibodies in neonates and the rapid waning of maternal antibody titer.

Research on pharmacological mechanism of the treatment of Asthma by oral Bordetella pertussis

Objective To examine the effect of oral Bordetella pertussis on the asthma mice sensitized by ovalbumin(OVA),and explore the possible mechanism.Methods Culture the B.pertussis in Bordet-Gengou agar containing 25% rabbit blood.Collect the bacteria and inactive them at 80 ℃ for 30 min to get whole killed B.pertussis.32 BALB/C mice were randomly divided into control group,model-control group,model group and treatment group.The mice were sensitized and challenged with OVA to establish asthma model.Asthma mice in treatment group were orally administrated with B.pertussis 7 days before sensitization.The mice in control group and model-control group were challenged with saline.After 24 hours of last challenge,bronchoaveolar lavage fluid(BALF)and peripheral blood were collected.The total cells and eosinophils were counted in BALF.Results Compared with the control group(2.03±0.42,0.33±0.82)×105 mL-1 and model-control group(2.16±0.48,0.16±0.41)×105 mL-1,the total cells(10.13±1.33)×105 mL-1 and eosinophils(11.83±4.573)×105 mL-1 in BALF were more in asthma mice(P<0.01).The number of total cells(5.50±1.55)×105 mL-1 and eosinophils(0.66±0.82)×105 mL-1 in BALF were reduced in asthma mice treated with B.pertussis compared with asthma mice(P<0.01).Conclusions Oral B.pertussis can inhabit airway inflammation of asthma mice and has the potential of treating asthma.

Characterization of two Achromobacter xylosoxidans isolates from patients with pertussis-like symptoms

Objective:To characterize two Achromobaeter xylosoxidans recovered from 2 patients diagnosed with pertussis during a Bordetella pertussis surveillance program.Methods:Nasopharyngeal swabs from 2 children under 1 year of age with clinical suspicion of pertussis were analyzed by culture and PCR.Results:Two Achromobaeter xylosoxidans A8,closely related to Bordetella spp.were recovered from 2 patients diagnosed of pertussis,both carrying the ptxA gene and IS418 the pertussis toxin encoding gene.Subsequently,antibiotic susceptibility was evaluated by disk-diffusion method and by PCR.Conclusions:Although more detailed studies are needed,the present data highlight the possibility that Achromobaeter xylosoxidans.closely related Bordetella pertussis microorganisms and not covered under the vaccine umbrella,might also result in cases of whooping cough.Thereby further surveillance is necessary to determine the extension and relevance of their pathogenic role in order to discriminate their real public health implication.

Aberration detection of pertussis from the Mazandaran province, Iran, from 2012 to 2018: Application of discrete wavelet transform

Objective:To define the level of alarm threshold for pertussisaberrations and to detect the aberrations of the reported suspectedcases of pertussis from the Mazandaran province in the north ofIran.Methods:The included cases were composed of the suspectedpertussis patients who came from Mazandaran province andregistered in the Center for Disease Control and Prevention from20 March 2012 to 20 March 2018.A discrete wavelet transformbasedmethod was used to detect the aberrations.All analyseswere performed using MATLAB Software version 2018a andExcel 2010.Results:A total of 1162 cases were recruited in the study,including 545(46.90%)males and 617(53.10%)females,withmedian age of 1.47(0.22-9.56)years.The median age of maleswas 1.18(0.21-8.24)years,while that of females was 1.82(0.21-10.75)years.Concerning the level of the alarm threshold,it was1.28 case/d when k=2,while it was 1.34 case/d when k=3.Thetotal detected aberration days were 123 d and 57 d by consideringk=2 and 3,respectively.The most defined alarm threshold wasrelated to spring(>2 cases/d)and summer(>1 case/d),respectively.Conclusions:The sensitivity of the surveillance system issubjected to a different time.Thus,determining the level of alarmthreshold periodically using different methods is recommended.

30 and 32 kDa outer membrane proteins of Bordetella pertussis as a modulator on promoting degranulation of mast cells

The correlation between the activities of the outer menbrane proteins （OMPs） of Bordetella pertussis and the lgE-mediated asthma was investigated in the present study, in which the OMPs of B. pertussis and their components were prepared by detergent treatment and chromatography, and the molecular weights of the OMPs components were determined by SDS-PAGE. The amounts of total as well as the ovalbumin （OVA）-specific IgE induced by dead B. pertussis whole bacterial vaccine on guinea pigs were detected by ELISA. Meanwhile, the effect of the OMPs and their components to promote the degranulation of guinea pig mast cells was observed by using the mast cell degranulation test, and ELISA assay was used to measure the histatmine levels in the supematants from the mast cell cultures. Histamine sensitive test was used to demonstrate the effects of the OMPs and their components to increase the histamine lethal sensitivity in mice. It was found that four components with molecular weights of 30, 32, 38 and 69 kDa could be obtained from the OMPs of B. pertussts, and the dead whole bacteria vaccine of B. pertussis had the ability to increase the levels of the total as well as the OVA-specific IgE in sera of guinea pigs. The OMPs and their 30 and 32 kDa components demonstrated significantly enhancing effect on the degranulation of guinea pig mast cells, and the histamine levels in the supematants from the mast cell culture treated with OMPs and their 30 and 32 kDa components were also significantly increased. It is evident that the strong adjuvant activity and the enhancing effect to degranulation of mast cells and the release of histamine of certain outer membrane components of B. pertussis could be demonstrated as revealed by the results of the present study, suggesting the possibility of a close relationship between the infection of vaccination with B. pertussis and the IgE-mediated asthma.

Resurgence of pertussis:reasons and coping strategies

Pertussis(whooping cough)is an acute and contagious respiratory disease caused by the pathogen Bordetella pertussis(B.pertussis).B.pertussis can infect individuals of all ages.Children with pertussis may experience severe and persistent coughing and paroxysms;for newborns and infants,pertussis may be life-threatening.The development and widespread administration of the pertussis vaccine had once successfully brought pertussis under control,maintaining it at a low level for many years.However,resurgence of pertussis has been reported in many countries even with high vaccination coverage recently.The resurgence of pertussis was first reported in the United States(USA)in 1993[1].During 2000–2016,the baseline incidence increased and the age distribution of pertussis changed in the USA[2].Other countries including Canada[3],Australia[4],European Union countries,and South Korea have also reported a rise in pertussis outbreaks[2,5].

Emergence of Erythromycin-Resistant and Pertactin-and Filamentous Hemagglutinin-Deficient Bordetella pertussis Strains—Beijing,China,2022-2023

What is already known about this topic?Pertussis has reemerged as a significant public health threat,primarily due to variations in Bordetella pertussis strains,antimicrobial resistance,and vaccine evasion.What is added by this report?All isolated strains were identified as ptxA1/ptxC2/ptxP3/prn150/fim2-1/fim3-1/fhaB1/tcfA2 type and exhibited resistance to erythromycin.

Analysis of prevailing pertussis strains from different regions in China after the application of acellular vaccines

To the Editor:With the extensive uptake of pertussis vaccine,morbidity and mortality related to pertussis have decreased significantly.The application of acellular vaccines(ACVs)occurred later in China than in developed countries;correspondingly,the pertussis resurgence in China also began later.The latest global genotype dynamic prediction model cannot explain the B.pertussis genotype change trend in China.[1]Chinese B.pertussis strains gradually formed their own unique developmental branches.[2]Here,a phylogenetic tree of prevailing B.pertussis strains from three different regions of China was visualized by EvolView(http://www.evolgenius.info/evolview.html).A total of 199 isolated B.pertussis strains were used for the phylogenetic analysis.The B.para-pertussis strain isolated from Tianjin was used as the out-group,and Chinese strain(CS),which is widely used as a vaccine strain for ACV production in China,was used as the reference strain.In particular,we analyzed the multilocus sequence typing(MLST)and macrolide-resistance-conferring gene mutations.

Biosynthesis and transfer of 2‑acetamido‑4‑methylamino‑l‑fucose to the core‑lipid A in Bordetella pertussis

The trisaccharide unit in lipopolysaccharide of Bordetella pertussis is important for immune recognition,but how the rare sugar 2-acetamido-4-methylamino-fucose in the trisaccharide unit is synthesized and transferred to the core of lipopolysaccharide in B.pertussis remains unclear.In this study,we demonstrated that the genes bplF,bplG,bplL and bplI are involved in the synthesis and transfer of 2-acetamido-4-methylamino-fucose to the core of lipopolysaccharide in B.pertussis.These genes were overexpressed with various combination in a recombinant E.coli strain which can synthesize B.pertussis corelipid A.Lipopolysaccharides were isolated from these strains and analyzed by using SDS-PAGE,ion chromatography and NMR.Based on these analyses,the mechanism of biosynthesis and transfer of 2-acetamido-4-methylamino-l-fucose to the core-lipid A in B.pertussis is proposed.

Coverage rates for diphtheria,tetanus,poliomyelitis,and pertussis age-specific booster recommendations in France:2018 update of the real-world cohort analysis

The French National Immunization Program was updated in 2013 for vaccination against diphtheria,tetanus,per-tussis,and poliomyelitis.Our previous findings on the evolution of age-specific booster vaccination coverage rates(VCRs)up to 2017 suggested suboptimal vaccination coverages due to the pre-2013 recommendation-residual vaccination practices.In the current analysis,we evaluated all age-specific booster VCR and distribution of age at vaccination visits in 2018.In this retrospective observational cohort study,the cumulative booster VCRs were updated at all vaccination visits up to 2018 among the people who were eligible for a booster vaccination,using a 1/97th random sample of French national healthcare reimbursement databases.The cumulative booster VCR for individuals from all age groups increased from 2017 to 2018,except for 85-years-old vaccination visit.Majority of the individuals from all age groups were vaccinated(boosted)with a vaccine containing the pertussis valence.In 2018,sharp peaks corresponding to the recommended ages for booster vaccination visits were observed for individuals aged 6,11 to 13,25,45,and 65 years.Our study reiterates suboptimal coverages in France and implies the need for booster vaccination throughout life for the protection of the population.

Clinical characteristics,molecular epidemiology and antimicrobial susceptibility of pertussis among children in southern China

Background Increasing numbers of pertussis cases have been reported in recent years.The reported cases from Shenzhen Children's Hospital were close to one tenth of all cases in China.The epidemiology of antigenic genotype and antibiotic resistance of circulating strains in children have been unknown in Shenzhen,southern China.The aim of this study was to describe the clinical features and explore the genotypes and antimicrobial susceptibility of circulating Bordetella pertussis among children in Shenzhen.Methods Data of hospitalized children with pertussis in Shenzhen Children's Hospital from August 2015 to April 2017 were collected.The genetic variability of isolates was investigated and Etest was performed for phenotypic susceptibility to erythromycin,azithromycin,clarithromycin,clindamycin,and trimethoprim/sulfamethoxazole.Results 469 children with pertussis confirmed by real-time quantitative polymerase chain reaction were hospitalized and strains were isolated from 105 patients.White blood cell count≥20×10^9/L and lymphocyte proportion≥60%were observed in 39.29%of infants younger than 3 months.The two predominant profiles of virulence-associated allelic genes were ptxA1/ptxC1/ptxPl/prnl(48.6%)and ptxA1/ptxC2/ptxP3/prn2(44.8%).Among the isolates,48.6%(51/105)were found resistant to macrolides.Conclusions These findings indicate that leukocytosis is not a sensitive indicator of pertussis.Isolates with the gene profile ptxP3/prn2 were highly circulating in Shenzhen and less resistant to macrolides,different from patterns observed in other parts of China.

Neuroprotective effects of nimodipine and MK-801 on acute infectious brain edema induced by injection of pertussis bacilli to neocortex of rats

Objective: To explore the mechanism and type of acute infectious brain edema induced by injection of pertussis bacilli (PB) in rat neocortex, to study the neuroprotective effect of non-competitive antagonist of N-methl-D-aspartate ( NMDA ) receptor ( MK-801 ) and antagonist of Ca 2+ channels ( nimodipine )on brain edema, and to investigate the relationship between percentage of water content and cytosolic free calcium concentration ( i) in synaptosomes or content of Evans Blue (EB). Methods: 95 SD rats were randomly divided into five groups, ie, normal control group, sham-operated control group, PB group, nimodipine treatment group and MK-801 pretreatment group. The acute infectious brain edema was induced by injection of PB into the rats. Quantitative measurements of water content and the concentration of EB were performed. i was determined in calcium fluorescent indication Fura-2/AM loaded neuronal synaptosome with a spectrofluorophotometer. To observe the effect of MK-801 and nimodipine, we administered MK-801 48 hours and 24 hours before the injection of PB in MK-801 pretreatment group, and nimodipine after the injection of PB in nimodipine treatment group. The specific binding of NMDA receptor was measured with -MK-801 in the neuronal membrane of cerebral cortex. Results: The levels of water content and EB content of brain tissues, and i in the neuronal synaptosomes increased more significantly in the PB-injected cerebral hemisphere in the PB group than those of normal control group and sham-operated control group (P< 0.05). The water content and i increased with the duration of infectious brain edema. Nimodipine administered after the injection of PB could significantly decrease the water content, EB and i (P< 0.05). MK-801 could significantly decrease the water content, EB and i in 4 h and 24 h groups (P< 0.05). The Kd values were 30.5 nmol/L ±3.0 nmol/L and 42.1 nmol/L ±4.2 nmol/L in PB group and NS group respectively (P< 0.05), and Bmax were 0.606 pmol/mg.pro ±0.087 pmol/mg.pro and 0.623 pmol/mg.pro ±0.082 pmol/mg.pro respectively, without statistical significance (P> 0.05). Conclusions: The changes in the permeability of blood-brain barrier (BBB) and Ca 2+-overload may participate in the pathogenesis of infectious brain edema. Treatment with nimodipine can dramatically reduce the damage of brain edema and demonstrate neuroprotective effect on brain edema by inhibiting the excess of Ca 2+ influx and reducing the permeability of BBB. MK-801 pretreatment may inhibit the delayed Ca 2+ influx into the neurons. The infectious brain edema is not only cytotoxic brain edema (intracellular edema) but also vasogenic brain edema (extracellular edema) followed by earlier BBB breakdown, so infectious brain edema is complicated with brain edema.

Pertussis toxin modulation of sodium channels in the central neurons of cyhalothrin-resistant and cyhalothrinsusceptible cotton bollworm, Helicoverpa armigera

Pertussis toxin （FIX） inhibits the activation of the α-subunit of the inhibitory heterotrimeric G-proteins （Cαi/o） and modulates voltage-gated sodium channels, which may be one of the primary targets of pyrethroids. To investigate the potential mechanisms of agricultural pests resistance to pyrethroid insecticides, we examined the modulations by PTX on sodium channels in the central neurons of the 3rd-4th instar larvae of cyhalothrin-resistant （Cy-R） and cyhaiothrin-susceptible （Cy-S） Helicoverpa armigera by the whole-cell patch-clamp technique. The isolated neurons were cultured for 12-16 h in an improved L15 insect culture medium with or without PTX （400 ng/mL）. The results showed that both the Cy-R and Cy-S sodium channels exhibited fast kinetics and tetrodotoxin （TTX） sensitivity. The Cy-R sodium channels exhibited not only altered gating properties, including a 8.88-mV right shift in voltage-dependent activation （V0.5act） and a 6.54-mV right shift in voltage-dependent inactivation （V0.5inact）, but also a reduced peak in sodium channel density （Ⅰdensity） （55.2% of that in Cy-S neurons）. Cy-R sodium channels also showed low excitability, as evidenced by right shift of activation potential （Ⅴacti） by 5-10 mV and peak potential （Ⅴpcak） by 20 mV. FIX exerted significant effects on Cy-S sodium channels, reducing sodium channel density by 70.04%, right shifting V0.5act by 14.41 mV and V0.5inact by 9. 38 mV. It did not cause any significant changes of the parameters mentioned above in the Cy-R sodium channels. The activation time （Tpeak） from latency to peak at peak voltage and the fast inactivation time constant （τinact） in both Cy-S and Cy-R neurons were not affected. The results suggest that cotton bollworm resistant to pyrethroid insecticides involves not only mutations and allosteric alterations of voltage-gated sodium channels, but also might implicate perturbation of PTX-sensitive Gαi/o-COupled signaling Wansduction pathways.

Protective Effect of Anisodsmine on Brain Edema Induced by Pertussis Bacilli in Rabbits

Objective: To observe the effect of 654-2 on brain edema model induced by pertussis bacilli in rabbits. Methods: Brain edema model of 26 rabbits induced by pertussis bacilli was prepared for observation,their brain water content and brain glutamate level were determined before and after treatment. Results: 654-2could decline the water content of brain and increase the glutamate level in brain tissue of the treatment group as compared with group without treatment. Conclusion: 654-2 has protective effect on brain edema induced by pertussis bacilli.

Changes of neuronal calcium channel following brain damage induced by injection of pertussis bacilli in rats

Objective: To explore changes of neuronal calcium channel following brain damage induced by injection of pertussis bacilli in rats, and to investigate the relationship between cytosolic free calcium concentration ([Ca 2+ ] i) in the synaptosome and Ca 2+ ATPase activities of mitochondria. Methods: The level of [Ca 2+ ] i in the synaptosome and Ca 2+ ATPase activities of mitochondria in the acute brain damage induced by injection of pertussis bacilli (PB) in rat was determined and nimodipine was administrated to show its effects on [Ca 2+ ] i in the synaptosome and on alteration of Ca 2+ ATPase activity in the mitochondria. Seventy three rats were randomly divided into four groups, ie, normal control group (Group A), sham operation control group (Group B), PB group (Group C) and nimodipine treatment group (Group D). Results: The level of [Ca 2+ ] i was significantly increased in the PB injected cerebral hemisphere in the Group C as compared with that in the Group A and the Group B at 30 minutes after injection of PB. The level of [Ca 2+ ] i was kept higher in the 4 hours and 24 hours subgroups after the injection in the Group C (P< 0.05 ). In contrast, the Ca 2+ ATPase activities were decreased remarkably among all of the subgroups in the Group C. Nimodipine, which was administered after injection of PB, could significantly decrease the [Ca 2+ ] i and increase the activity of Ca 2+ ATPase (P< 0.05 ). Conclusions: The neuronal calcium channel is opened after injection of PB. There is a negative correlation between activities of Ca 2+ ATPase and [Ca 2+ ] i. Nimodipine can reduce brain damage through stimulating the activities of Ca 2+ ATPase in the mitochondria, and decrease the level of [Ca 2+ ] i in the synaptosome. Treatment with nimodipine dramatically reduces the effects of brain damage induced by injection of PB.

Investigation of temporal and spatial heterogeneities of the immune responses to Bordetella pertussis infection in the lung and spleen of mice via analysis and modeling of dynamic microarray gene expression data

Bordetella pertussis(B.pertussis)is the causative agent of pertussis,also referenced as whooping cough.Although pertussis has been appropriately controlled by routine immunization of infants,it has experienced a resurgence since the beginning of the 21st century.Given that elucidating the immune response to pertussis is a crucial factor to improve therapeutic and preventive treatments,we re-analyzed a time course microarray dataset of B.pertussis infection by applying a newly developed dynamic data analysis pipeline.Our results indicate that the immune response to B.pertussis is highly dynamic and heterologous across different organs during infection.Th1 and Th17 cells,which are two critical types of T helper cell populations in the immune response to B.pertussis,and follicular T helper cells(TFHs),which are also essential for generating antibodies,might be generated at different time points and distinct locations after infection.This phenomenon may indicate that different lymphoid organs may have their unique functions during infection.These findings provide a better understanding of the basic immunology of bacterial infection,which may provide valuable insights for the improvement of pertussis vaccine design in the future.

A scoping review of studies on women's knowledge regarding Tdap vaccination during Pregnancy

This review aimed to determine and identify the knowledge and attitude of the mothers or pregnant women toward the Tdap vaccine during pregnancy.Whooping cough,Diphtheria disease and tetanus are infectious and pathogenic bacterial diseases that mainly affect children too young to complete basic vaccinations,and deaths associated with infectious diseases are frequent among them.Therefore,it is advisable for pregnant women to take the triple bacterial vaccine(tetanus,diphtheria and pertussis).This scoping review was conducted,and various electronic databases were searched,including Medline and PubMed.Moreover,Google Scholar,CDC,and immunization research group websites were searched to investigate the literature on the Tdap vaccine.As a result,13 studies were included in this review.Based on the findings of this review,the level of knowledge of ladies and pregnant women about the importance of the vaccine depended upon several factors,including education level,occupation,age,sources of vaccine information,maternal desire,being born outside the country,lower household income,religious misconception,residing in a province or area where the pertussis vaccine was not free,having given birth to live children in the past,and receiving maternity care from a midwife.Therefore,it can be concluded that the increase in the level of knowledge about the importance of Tdap vaccine increased the percentage of women who supported and accepted the vaccine.Studies have also shown that some mothers refused vaccination due to reservations about vaccine safety and efficacy since they did not have sufficient knowledge or experience.