Educational Interventions on Pregnancy Vaccinations during Childbirth Classes Improves Vaccine Coverages among Pregnant Women in Palermo’s Province

Maternal immunization is considered the best intervention in order to prevent influenza infection of pregnant women and influenza and pertussis infection of newborns. Despite the existing recommendations, vaccination coverage rates in Italy remain very low. Starting from August 2018, maternal immunization against influenza and diphtheria-tetanus-pertussis were strongly recommended by the Italian Ministry of Health. We conducted a cross sectional study to estimate the effectiveness of an educational intervention, conducted during childbirth classes in three general hospitals in the Palermo metropolitan area, Italy, on vaccination adherence during pregnancy. To this end, a questionnaire on knowledge, attitudes, and immunization practices was structured and self-administered to a sample of pregnant women attending childbirth classes. Then, an educational intervention on maternal immunization, followed by a counseling, was conducted by a Public Health medical doctor. After 30 days following the interventions, the adherence to the recommended vaccinations (influenza and pertussis) was evaluated. At the end of the study 326 women were enrolled and 201 responded to the follow-up survey. After the intervention, among the responding pregnant women 47.8% received influenza vaccination (+44.8%), 57.7% diphtheria-tetanus-pertussis vaccination (+50.7%) and 64.2% both the recommended vaccinations (+54.8%). A significant association was found between pregnant women that received at least one vaccination during pregnancy and higher educational level (graduation degree/master’s degree), employment status (employed part/full-time) and influenza vaccination adherence during past seasons (at least one during last five years). The implementation of vaccination educational interventions, including counseling by healthcare professionals (HCPs), on maternal immunization during childbirth courses improved considerably the vaccination adherence during pregnancy.

Immunobiological Properties of Biofilms of Bacteria of the Genus Bordetella

Relevance. Whooping cough remains a pressing public health problem worldwide, including in countries with high vaccination rates. One of the probable causes of the ongoing epidemic process of pertussis infection is B. pertussis biofilms, which differ from plankton cultures by an altered gene expression spectrum and are highly resistant to environmental conditions, antibiotics, and immune factors.Aims. Analysis of literature data on the genetic and molecular - cellular mechanisms of biofilm formation by bacteria of the genus Bordetella, as well as approaches to the search for means aimed at suppressing the growth of biofilms and the destruction of formed biofilms in the macroorganism.Conclusions. Biofilm formation by microbes of the genus Bordetella is a complex multistage process regulated by genetic signaling systems: the Bvg AS system and the 2-nucleotide (p) ppGrp system, as well as other regulatory proteins and the polysaccharide complex. The matrix of B. pertussis biofilms consists of extracellular DNA, proteins, and a polysaccharide polymer that play an important role in the formation of biofilms in the respiratory tract and on abiotic surfaces. The genetic and molecular-cellular processes of biofilm formation and maintenance, as well as the various components of the biofilm matrix, can serve as targets for new antimicrobial drugs and more effective pertussis vaccines that will better control the entire pertussis infection cycle, including colonization, persistence, and transmission of the causative agent. One of the approaches to the development of new-generation cell-free pertussis vaccines is the identification of new biofilm-associated antigens that can induce effective cellular and humoral responses. The search for drugs that can destroy biofilms, including substances that affect the matrix and facilitate the access of antibacterial drugs to microbial cells, is promising.

1183. Serum Bactericidal Activity Induced by Live Attenuated Pertussis Vaccine BPZE1 is Comparable to Boostrix™

Background In a Phase 2b, multi-center, placebo-controlled, randomized study, intranasal BPZE1 induced mucosal and serum antibodies to pertussis antigens and protected against subsequent colonization following attenuated challenge with BPZE1 3 months later. BoostrixTM also induced serum but not mucosal antibodies and did not protect against BPZE1 challenge. We have evaluated the induction of serum bactericidal activity (SBA) for Bordetella pertussis by BPZE1 or Boostrix vaccination. A previous study showed that Boostrix induction of SBA is dependent on Prn whereas B. pertussis infection induces SBA targeting Prn and other antigens. Methods A convenience set of subjects who had a broad range of Prn and PT IgG serum concentrations from treatment groups who received BPZE1+BPZE1 or Boostrix+Placebo (Day 1 and 85 vaccination) were randomly selected to assess SBA using B. pertussis strain B1917. Three timepoints (baseline, 28 days following first and second vaccination) were analyzed and interpolated 50% killing titers determined. The relationship to Prn IgG concentration was assessed. Results BPZE1 and Boostrix elicited similar and significant increases in SBA following vaccination. BPZE1 and Boostrix elicit anti-Prn IgG, with Boostrix eliciting higher concentrations. A greater SBA response relative to PRN IgG was observed for BPZE1 compared to Boostrix. SBA-Prn correlations were high post-Boostrix (0.74) as previously reported; correlation was lower (0.35) following BPZE1, suggesting the involvement of broader antigenic protection beyond Prn alone. Table of GMT and GMFR in SBA and Prn IgG Conclusion In this exploratory investigation, the novel intranasal live-attenuated pertussis vaccine BPZE1 induced SBA titers that were similar to Boostrix using a B. pertussis strain representative of current disease isolates. SBA-Prn correlations were high post-Boostrix, consistent with prior reports showing Prn is the acellular vaccine antigen that mediates SBA. In contrast, BPZE1 bactericidal antibodies appear broader than Prn which may be important given the global rise of Prn-deficient B. pertussis strains. Disclosures All Authors: No reported disclosures

Mucosal immunization with DTaP confers protection against Bordetella pertussis infection and cough in Sprague-Dawley rats

Pertussis is a respiratory disease caused by the Gram-negative pathogen, Bordetella pertussis ( Bp ). The transition from a whole cell pertussis vaccine (wP; DTP) to an acellular pertussis vaccine (aP; DTaP; Tdap) correlates with an increase in pertussis cases, despite widespread vaccine implementation and coverage, and it is now appreciated that the protection provided by aP rapidly wanes. To recapitulate the localized immunity observed from natural infection, mucosal vaccination with aP was explored using the coughing rat model of pertussis. Overall, our goal was to evaluate the route of vaccination in the coughing rat model of pertussis. Immunity induced by both oral gavage (OG) and intranasal (IN) vaccination of aP in Bp challenged rats over a nine-day infection was compared to intramuscular (IM)-wP and IM-aP immunized rats that were used as positive controls. Our data demonstrate that mucosal immunization of aP resulted in production of anti- Bp IgG antibody titers similar to IM-wP and IM-aP vaccinated controls post-challenge. IN-aP also induced anti- Bp IgA antibodies in the nasal cavity. Immunization with IM-wP, IM-aP, IN-aP, and OG-aP immunization protected against Bp induced cough, while OG-aP immunization did not protect against respiratory distress. Mucosal immunization by both IN and OG administration protected against acute inflammation and decreased bacterial burden in the lung compared to mock vaccinated challenge (MVC) rats. The data presented in this study suggests that mucosal vaccination with aP can induce a mucosal immune response and provide protection against Bp challenge. This study highlights the potential benefits and uses of the coughing rat model of pertussis; however, further questions regarding waning immunity still require additional investigation.

Use of a combined acellular vaccine against pertussis infection in children over four years of age: a cross-sectional study

An increase in the incidence of whooping cough has been noted in recent years in both unvaccinated and vaccinated children and adults. In Russia, recently, new possibilities of protection against pertussis infection have appeared for children over four years old and adults. Purpose: to analyze the specific immunoprophylaxis and safety of the vaccine against diphtheria, tetanus and pertussis for children over four years old in Krasnodar. Materials and methods. We examined 393 children over four years and 125 adults who were immunized with a vaccine for the prevention of diphtheria (with a reduced antigen content), tetanus, pertussis (acellular), combined, adsorbed (Adasel) at the SKIB city hospital in Krasnodar in the period from July 2018 until October 2019. The respondents had a vaccination history and did not suffer from whooping cough, according to medical records. Results. The number of people vaccinated with acellular vaccine doubled among the child population (2018 - 129; 2019 - 264) and adults (2018 - 39; 2019 - 86). General post-vaccination reactions among children amounted to 12.2% (48), weak responses prevailed - 36 (9.2%), strong responses were found in 12 people (3%). In adults, general post-vaccination responses were not observed. Local post-vaccination reactions among children amounted to 38.2% (150), weak reactions prevailed - 103 (26.2%), strong ones were found in 47 children (12%). Conclusions. During the study period, immunoprophylaxis with this vaccine doubled, showing a satisfactory safety profile. However, to reduce the incidence of whooping cough, it is advisable to examine the immunological protection and conduct revaccination with a booster dose to achieve stable post-vaccination immunity.

Pertussis in a child of the first month of life from family contact

A case of whooping cough in a moderate form in a child of the first month of life is described in the presented clinical observation. The moderate form was manifested by the duration of the preconvulsive period up to 5 days, the appearance of cyanosis of the face when coughing in the early stages of the disease (1 week), an increase in the number of coughing attacks. The difficulties of treating pertussis in young children are demonstrated by our observation of the course of the disease. There is no vaccination against pertussis in children in the family due to the refusal of parents and children with prolonged coughing were not examined at the outpatient stage. As a result, chemoprophylaxis was not performed on time and the newborn was discharged from the hospital to the center of pertussis infection. The solution to the problem of reducing the incidence in children in the first months of life should be vaccination of pregnant women in the last stages, and vaccination of the environment, including agerelated revaccinations.

Mucosal immunization with DTaP confers protection against Bordetella pertussis infection and cough in Sprague-Dawley rats

Pertussis is a respiratory disease caused by the Gram-negative pathogen, Bordetella pertussis (Bp). The transition from a whole cell pertussis vaccine (wP; DTP) to an acellular pertussis vaccine (aP; DTaP; Tdap) correlates with an increase in pertussis cases, despite widespread vaccine implementation and coverage, and it is now appreciated that the protection provided by aP rapidly wanes. To recapitulate the localized immunity observed from natural infection, mucosal vaccination with aP was explored using the coughing rat model of pertussis. Immunity induced by both oral gavage (OG) and intranasal (IN) vaccination of aP in Bp challenged rats over a nine-day infection was compared to intramuscular (IM)-wP and IM-aP immunized rats that were used as positive controls as IM immunization is the current route for wP and aP vaccination. Our data demonstrate that both IN and OG immunization of aP resulted in production of anti-Bp IgG antibody titers similar to IM-wP and IM-aP vaccinated controls post-challenge. IN-aP also induced anti-Bp IgA antibodies in the nasal cavity. Immunization with IM-wP, IM-aP, IN-aP, and OG-aP immunization protected against Bp induced cough, while OG-aP immunization did not protect against respiratory distress Mucosal immunization (IN-aP and OG-aP) also protected against acute inflammation and decreased bacterial burden in the lung compared to mock vaccinated challenge (MVC) rats. The data presented in this study suggests that mucosal vaccination with aP can induce a mucosal immune response and provide protection against Bp> challenge.

Hospital-based prospective study of pertussis in infants and close contacts in Tehran, Iran

Background Pertussis remain a global health concern, especially in infants too young to initiate their vaccination. Effective vaccination and high coverage limit the circulation of the pathogen, yet duration of protection is limited and boosters are recommended during a lifetime. In Iran, boosters are given at 18 months and 6 years old using whole pertussis vaccines for which efficacy is not known, and pertussis surveillance is scant with only sporadic biological diagnosis. Burden of pertussis is not well understood and local data are needed. Methods Hospital-based prospective study implementing molecular laboratory testing in infants aged ≤6 months and presenting ≥5 days of cough associated to one pertussis-like symptom in Tehran. Household and non-household contact cases of positive infants were evaluated by comprehensive pertussis diagnosis (molecular testing and serology) regardless of clinical signs. Clinical evaluation and source of infection were described. Results A total of 247 infants and 130 contact cases were enrolled. Pertussis diagnosis result was obtained for 199 infants and 104 contact cases. Infant population was mostly < 3 months old (79.9%; 157/199) and unvaccinated (62.3%; 124/199), 20.1% (40/199) of them were confirmed having B. pertussis infection. Greater cough duration and lymphocyte counts were the only symptoms associated to positivity. Half of the contact cases (51.0%; 53/104) had a B. pertussis infection, median age was 31 years old. A proportion of 28.3% (15/53) positive contacts did not report any symptom. However, 67.9% (36/53) and 3.8% (2/53) of them reported cough at inclusion or during the study, including 20.8% (11/53) who started coughing ≥7 days before infant cough onset. Overall, only five samples were successfully cultured. Conclusion These data evidenced the significant prevalence of pertussis infection among paucy or poorly symptomatic contacts of infants with pertussis infection. Widespread usage of molecular testing should be implemented to identify B. pertussis infections.