Timing social distancing to avert unmanageable COVID-19 hospital surges.

Following the April 16, 2020 release of the Opening Up America Again guidelines for relaxing coronavirus disease 2019 (COVID-19) social distancing policies, local leaders are concerned about future pandemic waves and lack robust strategies for tracking and suppressing transmission. Here, we present a strategy for triggering short-term shelter-in-place orders when hospital admissions surpass a threshold. We use stochastic optimization to derive triggers that ensure hospital surges will not exceed local capacity and lockdowns are as short as possible. For example, Austin, Texas-the fastest-growing large city in the United States-has adopted a COVID-19 response strategy based on this method. Assuming that the relaxation of social distancing increases the risk of infection sixfold, the optimal strategy will trigger a total of 135 d (90% prediction interval: 126 d to 141 d) of sheltering, allow schools to open in the fall, and result in an expected 2,929 deaths (90% prediction interval: 2,837 to 3,026) by September 2021, which is 29% of the annual mortality rate. In the months ahead, policy makers are likely to face difficult choices, and the extent of public restraint and cocooning of vulnerable populations may save or cost thousands of lives.

Effect of pyriproxyfen exposure on cocooning and gene expression in the silk gland of Bombyx mori （Linnaeus, 1758）.

Bombyx mori（Linnaeus, 1758） is an important economical insect, and the sericulture is a flourishing industry in many developing countries. Pyriproxyfen, a juvenile hormone pesticide, is often applied to cultivations widely in the world, and its exposure often resulted in silk yield reduction and non-cocooning. However, the effect of pyriproxyfen exposure on cocooning and gene expression level in the silk gland of B. mori has not been studied yet, and this study focused on the above issues. The result indicated that pyriproxyfen exposure can lead to silk gland injury, reduction of silk yield and cocooning rate. Furthermore, the expression levels of silk protein synthesis related genes were down regulated significantly. The same change trends were shown between PI3K/Akt and CncC/Keap1 pathway, which is the expressions of key genes can be elevated by pyriproxyfen exposure. In addition, the activity of detoxification enzymes (P450, GST and CarE) and the expression levels of detoxification genes were elevated after pyriproxyfen exposure, suggesting that detoxification enzymes may play an important role in detoxification of pyriproxyfen in silk gland. These results provided possible clues to the silk gland injury and gene transcriptional level changes in silkworm after pyriproxyfen exposure.

Social contact patterns of infants in deciding vaccination strategy: a prospective, cross-sectional, single-centre study.

Social contact between individuals is believed to be a fundamental cause in the transmission of many respiratory tract infections. Because they have not yet been fully vaccinated, infants are at high risk for contracting whooping cough, influenza and their serious complications. Therefore, determining infant social contact patterns is an important step in protecting them from respiratory tract infection. This study included 1200 healthy infants (<12 months of age). Social contact diaries were used to estimate the frequency and nature of the infants' social contacts. This survey also gathered information regarding the infants' respiratory symptoms and their frequency of attendance at crowded places over a period of 1 week. The diary return rate was 83.8% (N = 1006), and there was a total of 4706 contacts reported for these infants. The median daily contact number per capita was 4 (range 1-18). The median number of contacts with adolescents was 0 (range 0-7). Of the infants, 50.3% had contact with non-household individuals. The mothers had the longest contacts with their babies. Contacts with school children, frequency of attendance at crowded places and age were determined to be significant effective factors for reporting respiratory symptoms. Results suggest that school-age siblings and the mothers should be primarily vaccinated, and parents should keep their babies away from crowded places for protecting their infants.

[Is it ethically acceptable to invite a pregnant woman to enroll in a clinical trial with Tdap if it could entail not being vaccinated with Tdap before delivery?] / ¿Es éticamente aceptable invitar a una embarazada a participar en un ensayo clínico con dTpa si ello pudiera conllevar no vacunarse con dTpa antes del parto?

Pertussis incidence has increased in recent years, especially among infants aged <2months. A number of Spanish regions have started a vaccination program with Tdap vaccine to all pregnant women in the third trimester of pregnancy. An observational study has shown that this strategy reduces the number of cases of pertussis by 90% in infants aged <2months. Mathematical models showed that a cocooning strategy (i.e. vaccination of the mother at immediate postpartum, and other adults and adolescents who have close contact with the newborn and caregivers) will reduce the incidence of pertussis by 70% in infants aged <2months. It is intended to conduct a clinical trial in which 340 pregnant women will receive Tdap vaccine, whereas another 340 pregnant woman will be vaccinated soon after delivery. Vaccination with Tdap will be offered to all partners and caregivers of the newborn. After assessing both the ethical and scientific reasons supporting the trial, it is concluded that it is ethically and legally acceptable to invite pregnant women living in communities where Tdap vaccination has been implemented to participate in the trial.

[Pertussis immunization within three adult populations concerned by cocoon strategy in Île-de-France]. / Vaccination contre la coqueluche au sein de trois populations d'adultes concernées par le cocooning en Île-de-France.

BACKGROUND: Pertussis is a highly contagious respiratory tract infection with a high morbi-mortality in non or insufficiently immunized infants. Cocoon strategy was implemented in France in 2004 in order to reduce the disease incidence. The main objective of the study was to estimate immunization coverage according to cocoon strategy among eligible adults in three different settings in Île-de-France. METHODS: A descriptive survey was carried out by means of the same questionnaire addressed to relatives of children hospitalized in pediatric wards, to adults living under the same roof as children enrolled in nursery school, and to grandparents who consulted general practitioners. The main outcome was pertussis vaccination of the adult before the child reached 6 months of age. Parent's and grandparent's knowledge about pertussis and medical advice received about cocooning were assessed. The statistical analysis searched for determinants of vaccination according to cocoon strategy. RESULTS: Between August 2014 and March 2015, 383 adults were included within the scope of the survey of whom 250 had a vaccination status that could be verified. Immunization coverage was 59%, 33% and 31% respectively in relatives of children hospitalized in pediatric wards, in adults living with children enrolled in nursery school, and in grandparents who consulted general practitioners offices. In the entire population, knowledge of the risk of pertussis was noted in 60%, 76% and 91% of cases. The main determinant of adequate and documented pertussis vaccination was "having received medical advice" that was present in 54%, 31% and 19% of cases, respectively. CONCLUSION: Cocoon strategy implementation has clearly progressed but remains insufficient. Emphasis needs to be placed on physicians' involvement in pertussis vaccination in adults eligible for cocoon strategy.

An Assessment of the Cocooning Strategy for Preventing Infant Pertussis-United States, 2011.

BACKGROUND: Infants are at greatest risk for severe pertussis. In 2006, the Advisory Committee on Immunization Practices recommended that adolescents and adults, especially those with infant contact, receive a single dose of Tdap (tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine). To assess the effectiveness of cocooning, we conducted a case-control evaluation of infant close contacts. METHODS: Pertussis cases aged <2 months with onset between 1 January 2011 and 31 December 2011 were identified in Emerging Infections Program Network sites. For each case, we recruited 3 controls from birth certificates and interviewed identified adult close contacts (CCs) or parents of CCs aged <18 years. Pertussis vaccination was verified through medical providers and/or immunization registries. RESULTS: Forty-two cases were enrolled, with 154 matched controls. Around enrolled infants, 859 CCs were identified (600 adult and 259 nonadult). An average of 5.4 CCs was identified per case and 4.1 CCs per control. Five hundred fifty-four (64.5%) CCs were enrolled (371 adult and 183 non-adult CCs); 119 (32.1% of enrolled) adult CCs had received Tdap. The proportion of Tdap-vaccinated adult CCs was similar between cases and controls (P = .89). The 600 identified adult CCs comprised 172 potential cocoons; 71 (41.3%) potential cocoons had all identified adult CCs enrolled. Of these, 9 were fully vaccinated and 43.7% contained no Tdap-vaccinated adults. The proportion of fully vaccinated case (4.8%) and control (10.0%) cocoons was similar (P = .43). CONCLUSIONS: Low Tdap coverage among adult CCs reinforces the difficulty of implementing the cocooning strategy and the importance of vaccination during pregnancy to prevent infant pertussis.

Pertussis vaccination coverage among Australian women prior to childbirth in the cocooning era: a two-hospital, cross-sectional survey, 2010 to 2013.

BACKGROUND: Recent pertussis epidemics have triggered implementation of cocooning, involving caregiver vaccination to indirectly protecting susceptible infants. AIM: To determine patient, provider and setting factors associated with maternal pertussis booster vaccination (dTpa) within 5-10 years before childbirth. MATERIALS AND METHODS: Cross-sectional survey using Health Belief Model constructs among postpartum women in a tertiary referral centre and a private hospital in Sydney, Australia. RESULTS: Pertussis vaccination was current among 33.7% of the 2483 new mothers (0.5% vaccinated during pregnancy). Women were more likely to be vaccinated if they had heard of 'whooping cough' from a health professional (OR: 2.59, P < 0.001, 95% CI: 1.70-3.95), were recommended the vaccine (OR: 2.48, P < 0.00, 95% CI: 1.55-4.00), perceived pertussis as 'severe' for adults (OR: 1.21, p0.009, 95% CI: 1.05-1.39) and 'common' within their community (OR: 1.38, P < 0.001, 95% CI: 1.18-1.61). They more often agreed that it was their parental responsibility to be vaccinated (OR: 1.61, P = 0.002, 95% CI: 1.19-2.18), and this would help prevent their baby from contracting pertussis (OR: 1.22, P = 0.046, 95% CI: 1.00-1.47). Vaccinated women were less likely to report vaccination barriers: time constraints (OR: 0.75, P < 0.001, 95% CI: 0.66-0.85) and having safety concerns (OR: 0.80, P < 0.001, 95% CI: 0.69-0.92). Additionally, their partners reported three times higher uptake (76% vs 49%; P < 0.001; 95% CI: 2.66-3.85). CONCLUSIONS: Current pertussis vaccination in only one in every three postpartum participants may indicate insufficient coverage to protect newborns. Practitioners are instrumental in raising awareness and addressing vaccine concerns. Integrating vaccination into routine obstetric care, whether antenatally or postnatally, may minimise barriers.

The benefits of influenza vaccine in pregnancy for the fetus and the infant younger than six months of age.

Influenza is a serious problem for infants <6 months of age, whose hospitalization rates for influenza and associated illness are comparable with rates in the elderly. Because influenza vaccines are not effective in this age group, the optimal evidence-based strategy is to administer trivalent inactivated influenza vaccines during pregnancy. Immunizing with trivalent inactivated influenza vaccines in the second and third trimester is well studied and safe, not only providing protection for the pregnant woman and her infant <6 months of age, but also for the fetus by decreasing the risk for low birth weight.

La grippe est un grave problème pour les nourrissons de moins de six mois. Chez ces nourrissons, le taux d'hospitalisation attribuable à cette maladie et à des maladies connexes est comparable à celui des personnes âgées. Puisque les vaccins antigrippaux ne sont pas efficaces dans ce groupe d'âge, la stratégie optimale, fondée sur des données probantes, consiste à administrer les vaccins trivalents inactivés pendant la grossesse. L'administration de ces vaccins au cours des deuxième et troisième trimestres a fait l'objet d'études approfondies et est sécuritaire. Non seulement protège-t-elle la femme enceinte et son nourrisson de moins de six mois, mais elle est également bénéfique pour le fœtus. En effet, ce vaccin contribue à réduire le risque de faible poids à la naissance.

The benefits of influenza vaccine in pregnancy for the fetus and the infant younger than six months of age.

Influenza is a serious problem for infants <6 months of age, whose hospitalization rates for influenza and associated illness are comparable with rates in the elderly. Because influenza vaccines are not effective in this age group, the optimal evidence-based strategy is to administer trivalent inactivated influenza vaccines during pregnancy. Immunizing with trivalent inactivated influenza vaccines in the second and third trimester is well studied and safe, not only providing protection for the pregnant woman and her infant <6 months of age, but also for the fetus by decreasing the risk for low birth weight.

La grippe est un grave problème pour les nourrissons de moins de six mois. Chez ces nourrissons, le taux d'hospitalisation attribuable à cette maladie et à des maladies connexes est comparable à celui des personnes âgées. Puisque les vaccins antigrippaux ne sont pas efficaces dans ce groupe d'âge, la stratégie optimale, fondée sur des données probantes, consiste à administrer les vaccins trivalents inactivés pendant la grossesse. L'administration de ces vaccins au cours des deuxième et troisième trimestres a fait l'objet d'études approfondies et est sécuritaire. Non seulement protège-t-elle la femme enceinte et son nourrisson de moins de six mois, mais elle est également bénéfique pour le fœtus. En effet, ce vaccin contribue à réduire le risque de faible poids à la naissance.

Interventional study to improve pertussis and influenza vaccination uptake in pregnant women.

OBJECTIVES: Pertussis and influenza are endemic infections and associated with relevant morbidity and mortality in newborns and young infants. The Swiss Federal Office of Public Health has recommended influenza vaccination since 2011 and pertussis vaccination in pregnancy (ViP) since 2013 and expanded to repetition in each pregnancy since 2017. ViP is safe and effective in preventing severe diseases, but implementation is a challenge. We hypothesized that the proportion of women receiving ViP is persistently low despite existing national recommendations. Our primary objective was to compare the proportion of pertussis and influenza vaccine recommendations for and its acceptance by pregnant women before and after an information campaign tailored to obstetricians. Secondly, we aimed to identify reasons for missing or declining ViP. STUDY DESIGN: We conducted a prospective, single-center, single-arm implementation study in the maternity ward at the University Women's Hospital Basel. We performed standardized interviews with women hospitalized for postpartum care before (October to December 2019, Phase 1, n = 262) and after an information campaign (October to December 2020, Phase 2, n = 233) and compared categorical variables using chi-squared or Fisher's exact test and continuous variables using Whitney Mann U test. RESULTS: We found no significant differences in the proportion of recommendation for pertussis ViP (80 % vs. 84 %, p = 0.25) and implementation (76 % vs. 78 %, p = 0.63) between Phase 1 and 2. Main reasons for missing or declining vaccinations were lack of recommendation (62.8 %) and safety concerns regarding the unborn child (17.7 %). In contrast, the proportion of recommendation for influenza ViP (45 % vs. 63 %, p < 0.001) and implementation (29 % vs. 43 %, p < 0.001) increased significantly. CONCLUSION: Proactive recommendations by obstetricians play a key role in the implementation of ViP but is still insufficient in our setting. We believe that future efforts should aim to explore possible hurdles that impede recommendations by obstetricians for ViP. The focus should be on the needs and experiences of obstetricians in private practice, but also other health care professionals involved in care of pregnant women. Local campaigns do not seem effective enough, therefore national campaigns with new strategies are desirable.

Effectiveness of cocoon strategy vaccination on prevention of influenza-like illness in young infants.

During the initial half-year of their existence, infants cannot receive the influenza vaccine, yet they face the greatest susceptibility to severe influenza complications. In this study, we seek to determine whether influenza vaccination of maternal and household contacts is associated with a reduced risk of influenza-like illness (ILI) and severe acute respiratory infection (SARI) in infants. This work was prospectively conducted during the influenza season. A total of 206 infants were included in this study. The percentage of infants with only the mother vaccinated is 12.6% (n:26), and the percent of infants with all household contacts vaccinated is 16% (n:33). Among the infants with only the mother vaccinated, the effectiveness of influenza vaccine is estimated as 35.3% for ILI and 41.3% for SARI. Among infants with all household contacts vaccinated, the effectiveness is estimated as 48.9% for ILI and 76.9% for SARI. Based on the results of multivariate logistic regression analysis, all-household vaccination is a protective factor against SARI (OR: 0.07 95% CI [0.01-0.56]), household size (OR: 1.75, 95% CI [1.24-2.48]) and presence of secondhand smoke (OR: 2.2, 95% CI [1.12-4.45]) significant risk factors for SARI in infants. The mother alone being vaccinated is not a statistically significant protective factor against ILI (OR: 0.46, 95% CI [0.19-1.18]) or SARI (OR: 0.3, 95% CI [0.11-1.21]). Along with the obtained results and analysis, this study provides clear evidence that influenza vaccination of all household contacts of infants aged 0-6 months is significantly associated with protecting infants from both ILI and SARI.

Impact of postpartum influenza vaccination of mothers and household contacts in preventing febrile episodes, influenza-like illness, healthcare seeking, and administration of antibiotics in young infants during the 2012-2013 influenza season.

BACKGROUND: Influenza is associated with an increased risk for serious illness, hospitalization, and mortality in infants aged <6 months. However, influenza vaccines are not licensed for administration in this age group. The study evaluated the effectiveness of postpartum influenza vaccination of mothers and household members in infants. METHODS: The influenza vaccine was offered to mothers and household members of neonates born or hospitalized in 3 hospitals prior to the 2012-2013 season. Mothers were contacted every 2 weeks during the influenza season, and data regarding the onset of fever and/or respiratory symptoms in infants, healthcare seeking, hospitalization, and administration of antibiotics were collected. RESULTS: The study group consisted of 553 mothers who delivered 573 neonates. The influenza vaccine was administered to 841 of 1844 (45.6%) household contacts. Vaccination coverage rates ranged between 41.9% for neonates siblings and 49% for mothers. Five hundred thirty infants were analyzed for vaccine effectiveness. For outcomes in the infant, postpartum maternal vaccination had 37.7% effectiveness against acute respiratory illness (ARI), 50.3% against a febrile episode, 53.5% against influenza-like illness (ILI), 41.8% against related healthcare seeking, and 45.4% against administration of antibiotics. Multiple logistic regression analyses showed that maternal influenza vaccination was significantly associated with a decreased probability for febrile episodes, ARIs, and/or ILIs in infants, related healthcare seeking, and/or administration of antibiotics during the influenza season. Vaccination of other household contacts had no impact. CONCLUSIONS: Maternal postpartum vaccination against influenza was associated with a significant reduction of influenza-related morbidity, healthcare seeking, and antibiotic prescription in infants during the influenza season.

[Prevention of pertussis in newborns: Should pregnant women be vaccinated at each pregnancy?] / Prévention de la coqueluche chez le nouveau-né : faut-il vacciner les femmes enceintes à chaque grossesse ?

Pertussis is a respiratory disease that can be fatal at all ages but especially in infants before their mandatory vaccination. Recent epidemiological data shows a decrease in the number of pertussis cases, but a resurgence cannot be excluded in the coming years due to the cyclic evolution of the disease and the loosening of hygiene measures. Two approaches are used to protect infants before their vaccination: vaccination of the mother during pregnancy and vaccination of all the infant's close relatives (cocooning). The vaccination of the mother during pregnancy is more effective. The uncertain risk of chorioamniotitis associated with vaccination during pregnancy is insufficient to question this strategy.

'Cocooning' in prison during COVID-19: Findings from recent research in Ireland.

The advent of COVID-19 prompted the enforced isolation of elderly and vulnerable populations around the world, for their own safety. For people in prison, these restrictions risked compounding the isolation and harm they experienced. At the same time, the pandemic created barriers to prison oversight when it was most needed to ensure that the state upheld the rights and wellbeing of those in custody. This article reports findings from a unique collaboration in Ireland between the Office of the Inspector of Prisons - a national prison oversight body - and academic criminologists. Early in the pandemic, they cooperated to hear the voices of people 'cocooning' - isolated because of their advanced age or a medical vulnerability - in Irish prisons by providing journals to this cohort, analysing the data, and encouraging the Irish Prison Service to change practices accordingly. The findings indicated that 'cocooners' were initially ambivalent about these new restrictions, both experiencing them as a punishment akin to solitary confinement, and understanding the goal of protection. As time passed, however, participants reported a drastic impact on their mental and physical health, and implications for their (already limited) agency and relationships with others, experienced more or less severely depending on staff and management practices. The paper also discusses the implications for prison practices during and following the pandemic, understanding isolation in the penological context, and collaboration between prison oversight bodies and academics.

[Should French pregnant women be vaccinated against pertussis during pregnancy?] / Faut-il vacciner les femmes enceintes françaises contre la coqueluche ?

Many countries with a high perinatal level have started a policy of vaccination of pregnant women against pertussis. To date, France has not chosen this policy. The objective was to review knowledge on pertussis mortality in infants. Compare the strategies available to protect the infant before his first vaccination, scheduled for two months of age. We proceeded to a litterature analysis, from January 1998 to 2021. Search by the following keywords used ; "Whooping cough, vaccination, pregnancy, strategy, cocooning", on the scientific basis of "Pubmed", as well as French and foreign vaccination recommendations. Currently 90% of whooping cough deaths are concerning infants under six months of age and this mortality represents 2% of mortality in the first year of life. Vaccination at birth is not effective. The cocooning strategy, which consists of vaccinating those around the child, is expensive and difficult to implement. A systematic vaccination policy for pregnant women is effective and reasonably expensive when compared to the cocooning strategy. In England, it was recently accompanied by a 78% reduction in confirmed cases of pertussis in infants under six months of age. In conclusion, compared to cocooning strategy, pertussis vaccination of pregnant women appears more effective and cost-effective, and this with each pregnancy.

Intention and Attitude to Accept a Pertussis Cocooning Vaccination among Chinese Children's Guardians: A Cross-Sectional Survey.

OBJECTIVE: to assess Chinese children's guardians' intentions and attitudes toward accepting a pertussis cocooning vaccination and its determinants. METHODS: a self-administered questionnaire was designed based on a theoretical framework that originated mainly from the reasoned action approach. Associations between questionnaire variables and outcomes were assessed using univariate and multivariate analyses with odds ratios (OR), regression coefficients (ß), and their 95% confidence intervals (CIs). RESULTS: among 762 eligible participants, most (80.71%) reported a positive intention to accept a pertussis cocooning vaccination. The guardians' positive intention was related to the children's pertussis vaccination experience (OR = 2.483, 95% CI: 1.340-4.600). Guardians who had a positive attitude towards pertussis vaccination (OR = 1.554, 95% CI: 1.053-2.296), higher subjective norms (OR = 1.960, 95% CI: 1.371-2.802) and better perceived behavioral control (OR = 7.482, 95% CI: 4.829-11.591) stated a higher intention to receive a pertussis cocooning vaccination. The mean attitude score was 3.88 ± 0.863. Greater risk perception about pertussis (ß = 0.390, 95% CI: 0.298-0.483), stronger obligation from moral norms (ß = 0.355, 95% CI: 0.279-0.430), and good knowledge (ß = 0.108, 95% CI: 0.070-0.146) were significantly related to positive attitude toward pertussis cocooning vaccination among guardians. CONCLUSIONS: Chinese children's guardians held positive intentions and attitudes toward accepting a pertussis cocooning vaccination. The current findings described the determinants of such intention and attitude and provided knowledge based on improving guardians' intentions for policymakers if cocooning vaccinations or related immunization strategies are implemented in China in the future.

Cocooning strategy: Pertussis vaccination coverage rate of parents with a new-born in 2016 and 2017 in France.

Background: The "cocooning" strategy was introduced in 2004 to protect infants too young to be vaccinated against pertussis, by immunizing their parents and close relatives. The study objective was to assess its implementation 12 years after its introduction by estimating the pertussis vaccination coverage rates (VCR) among parents of newborns. Materials and methods: Pertussis VCR were estimated among all women who gave birth and men who took paternity leave, in 2016 or 2017, from a 1/97th random sample of French claims data. Two distinct study periods were defined based on current recommendations for the cocooning strategy: the "common practice" and the "parental project" periods. Results: In 2016, the pertussis VCR of women having given birth and men having taken paternity leave was 47.2 and 47.1%, respectively (46.1 and 45.6% in 2017, respectively). About one quarter of vaccinations were performed during the "parental project" period, with the vaccine most frequently reimbursed during the month of childbirth for women (57.1% in 2016 and 49.4% in 2017) and before or during the month the paternity leave began for men (about 78% in both 2016 and 2017). General practitioners were the main prescribers in private practice, even during the "parental project" period. Conclusion: To optimize the protection for infants, the main objective of the cocooning strategy, pertussis immunization coverage of adults and seniors needs to be improved. Moreover, cocooning vaccination linked to a parental project needs to be performed earlier, during pregnancy (for those around the mother) or in immediate post-partum (e.g., during the maternity stay).

Effect of a postpartum prescription for pertussis vaccine: a before-and-after study.

BACKGROUND: Among the strategies to encourage pregnant women to be vaccinated against pertussis in the postpartum period, that of giving them a prescription has been evaluated only sparsely. OBJECTIVE: To measure the effect of giving women who are not immunized against pertussis a prescription for the vaccine at discharge from the maternity unit. MATERIAL AND METHODS: Single-center before-and-after study (2011: before; 2015: after). All women received both oral and written information about vaccination against pertussis. During the after period, they were also specifically asked their immunization status during pregnancy. Those currently unimmunized received a written prescription for it at discharge. RESULTS: Among the women unimmunized at delivery, the percentage who were vaccinated postpartum climbed from 17 to 42% between 2011 and 2015 (p < 0.001), while the percentage of their unimmunized partners who were vaccinated remained stable (27 and 29%, p = 0.74). During this time, the percentage of women immunized against pertussis at the beginning of pregnancy rose from 32 to 52% (p < 0.001). Finally, the percentage of all women protected against this disease postpartum climbed from 44 to 72% between these two periods (p < 0.001). CONCLUSIONS: In the postpartum period, giving a prescription for pertussis vaccine to women unimmunized is accompanied by a significant elevation in their vaccination rate. Nevertheless, this rate remains low and better strategies have to be implemented.

Strategies to increase uptake of maternal pertussis vaccination.

INTRODUCTION: Pertussis is a highly contagious respiratory disease that results in disproportionate morbidity and mortality in infants who have yet to receive the primary diphtheria-tetanus-pertussis vaccine series. In the preceding decades numerous countries began to pursue either prenatal vaccination of pregnant women or postpartum vaccination of caregivers to protect infants. Despite proven benefit, maternal uptake of pertussis vaccine continues to remain suboptimal. AREAS COVERED: Many studies have been conducted to address the suboptimal uptake of maternal pertussis vaccination. This systematic review was undertaken to systematically identify those studies, highlight the most successful strategies and find the knowledge gaps that need to be filled over the coming years to improve vaccine uptake. Twenty-five studies were identified from six different databases. EXPERT OPINION: Five different interventions were shown to be successful in promoting uptake of pertussis vaccination: (1) standing orders, (2) opt-in orders, (3) provider education, (4) on-site vaccination and (5) interactive patient education. Three major knowledge gaps were also identified that need to be filled over the coming years: (1) lack of studies in low- and middle-income countries, (2) lack of studies targeting midwives and/or home birth and (3) lack of studies on the process of vaccine communication.

Factors associated with referring close contacts to an app with individually-tailored vaccine information.

BACKGROUND: Infants too young to be fully vaccinated are vulnerable to potentially deadly influenza and pertussis infections. The cocooning strategy limits this risk by vaccinating those likely to interact with the infant and mother during this vulnerable time, such as close friends and family members. Distribution of accurate and accessible vaccine information through existing social networks could be an important tool in increasing vaccine confidence and coverage. METHODS: We surveyed 1095 pregnant women from diverse prenatal care practices in Georgia and Colorado. These women were surveyed through a mobile app to assess vaccine intentions, attitudes, beliefs, norms, and levels of trust, and then presented brief individually-tailored educational videos about maternal and infant vaccines and the cocooning strategy. They were then given the opportunity to refer up to six contacts to enroll in the app and receive similar vaccine education. RESULTS: Twenty-eight percent of these women referred at least one contact, with an average of 2.67 contacts per referring woman. Most referrals (93%) were partners, parents, siblings, relatives, or close friends. Attitudinal constructs significantly associated with increased likelihood of referring contacts included: intention to receive maternal influenza vaccine, perceived safety of maternal Tdap vaccine, perceived efficacy of maternal influenza vaccine, perceived susceptibility to and severity of influenza during pregnancy, and trust in vaccine information from the Centers for Disease Control and Prevention (CDC) and academic institutions. Uncertainty about infant vaccine intentions was associated with decreased likelihood of referring contacts. CONCLUSIONS: Pregnant women who valued vaccination and trusted vaccine information from academic institutions were more likely to refer an educational app about vaccines than those who did not. Further research is needed to determine the potential impact of this strategy on vaccine coverage when implemented on a large scale. TRIAL REGISTRATION: The survey informing this article was part of a randomized controlled trial funded by the National Institutes of Health [clinicaltrials.gov registration number NCT02898688].