- Email: [email protected]
Cocooning Infants: Tdap Immunization for New Parents in the Pediatric Office
Cocooning Infants: Tdap Immunization for New Parents in the Pediatric Office Emmanuel B. Walter, MD, MPH; Norma Allred, PhD, MSN; Beth Rowe-West, RN, BSN; Kathlene Chmielewski, AS; Katrina Kretsinger, MD, MA; Rowena J. Dolor, MD, MHS Objective.—Vaccination with tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) is recommended for adults who have close contact with infants aged <12 months to protect young infants from infection due to Bordetella pertussis. This study assessed the acceptance of Tdap vaccination among parents bringing their newborn to a pediatric office during the first month of life. Methods.—Parents of all newborns were consecutively approached for participation by a study coordinator who provided written information about the study and a Tdap vaccine information sheet. After obtaining informed consent, a study coordinator reviewed contraindications for Tdap vaccination. Tdap vaccine was given by a clinic nurse, but parents with a history of ever receiving Tdap vaccine or of receiving a tetanus and diphtheria vaccine (Td) within the previous 2 years were excluded.
Results.—Two hundred parents were approached for study participation, of whom 40 (20%) were ineligible to receive Tdap vaccine primarily due to receipt of Td vaccine within the previous 2 years (32/40). Of the 160 eligible to receive Tdap vaccine, 82 (51.2%) received a dose. Although nearly 60% of vaccinated parents received Tdap vaccine the first time they were approached, over 40% received Tdap vaccine at a subsequent office visit occurring during the baby’s first month of life. Conclusions.—Offering Tdap vaccine in the pediatric office increases access to vaccination for both new fathers and mothers. When hospital-based, postpartum Tdap vaccination is not a routine practice, office-based vaccination of parents offers an option for protecting young infants.
S
The Centers for Disease Control and Prevention Advisory Committee on Immunization Practices emphasizes the importance of administering Tdap vaccine to adults who have or anticipate having close contact with an infant aged <12 months.1 The concept of vaccinating a baby’s close contacts and thereby interrupting transmission of disease to the infant has been termed a ‘‘cocoon’’ approach to preventing pertussis in the youngest children. New mothers who have not previously received Tdap vaccine should receive a dose during the immediate postpartum period. If Tdap vaccine is not administered to new mothers prior to hospital discharge, it should be administered promptly thereafter.8 New fathers and other adults in close contact with infants should ideally receive Tdap vaccine at least 2 weeks before beginning close contact with the infant. The purpose of this evaluation is to determine acceptance of a free Tdap vaccine when routinely offered to new parents in the pediatric office setting under ideal study conditions.
KEY WORDS: infants; pertussis; vaccine Academic Pediatrics 2009;9:344–7
ince the 1980s, the number of reported cases of pertussis in the United States increased dramatically. The first marked decline in disease was recorded during 2006, the year after licensure of Tdap (the tetanus toxoid, diphtheria toxoid, and acellular pertussis vaccine) for older children, adolescents, and adults in the United States.1,2 Increasing rates of pertussis have also been noted among infants aged 4 months and younger, who are at the highest risk of being hospitalized and suffering from complications secondary to pertussis.1,3,4 In many infant cases, the source of pertussis infection remains unknown. When identified, however, infant infection is most often acquired from a parent or older sibling.5–7 From the Primary Care Research Consortium, Duke University Medical Center, Durham, NC (Dr Walter, Dr Dolor, Ms Chmielewski); National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Ga (Dr Allred and Dr Kretsinger); and Immunization Branch, North Carolina Department of Health and Human Services, Raleigh, NC (Ms Rowe-West). Dr Walter is a speaker for Sanofi Pasteur and has served as a principal investigator for other clinical investigations sponsored by Sanofi Pasteur. The views in this article are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention, U.S. Department of Health and Human Services. Address correspondence to Emmanuel B. Walter, MD, MPH, Duke Children’s Primary Care Clinic, 4020 N Roxboro Rd, Durham, North Carolina 27704 (e-mail: [email protected]). Received for publication December 4, 2008; and in revised form May 13, 2009. accepted May 19, 2009. ACADEMIC PEDIATRICS Copyright Ó 2009 by Academic Pediatric Association
METHODS Study Design During a 5-month intervention period in 2007, parents of newborns whose medical care was initiated at a community-based, university-affiliated pediatric practice were routinely offered Tdap vaccine. The primary study outcome was Tdap vaccine coverage among parents of newborns. The study was conducted in a pediatric practice
344
Volume 9, Number 5 September–October 2009
ACADEMIC PEDIATRICS
Tdap Immunization for New Parents in the Pediatric Office
345
serving a highly educated parent population where both parents frequently attend their child’s medical appointments. Furthermore, a dedicated study coordinator tracked new parents, and Tdap vaccination was provided at no charge to the parent or insurance. Medical records of newborns presenting to the clinic during the study period were retrospectively reviewed to obtain newborn and parental demographic information.
ethnicity, insurance status, number of siblings, and mother’s age. Descriptive analyses were used to evaluate demographic characteristics of the newborns and mothers in addition to vaccine coverage rates. A Fisher exact test was used to assess the relationship between demographic characteristics and Tdap vaccine coverage. Analyses were conducted by using JMP version 7 (SAS Institute Inc, Cary, NC).
Study Population and Human Subjects The study population included parents whose newborns received medical care during the first month of life, including well-child care or weight- and feeding-related checkups, at the Duke Primary Care Clinic at Pickett Road, Durham, North Carolina. At the time this study was conducted, Tdap vaccine was not being routinely offered at local birthing hospitals, so new parents had not received Tdap vaccine in the peripartum period. The Institutional Review Board of Duke University Medical Center approved the research protocol.
RESULTS
Study Procedures Parents were introduced to the study by a clinic pediatrician or nurse and subsequently met with a research coordinator who further explained study procedures and provided a copy of the Tdap Vaccine Information Statement of the Centers for Disease Control and Prevention for review. Either parent alone or both parents could be present to be approached about study participation. Parents were asked to participate in the study, which involved receiving Tdap vaccine and completing a survey about reasons for Tdap vaccine refusal. Parents were screened for potential vaccine eligibility and were excluded from receiving Tdap vaccine if the following conditions were present: parental history of receipt of a prior Tdap vaccine or a tetanus and diphtheria vaccine (Td) within the preceding 2 years; a history of a bleeding disorder, Guillain-Barre´ syndrome, any ongoing neurological disorder, or fever in the preceding 24 hours; a life-threatening allergic reaction, a long seizure or coma within 7 days, or severe local limb swelling or pain after previously receiving a vaccine containing diphtheria toxoid, tetanus toxoid, or pertussis antigens. Parents were required to sign a written informed consent to either receive Tdap vaccine or to complete the survey about reasons for Tdap vaccine refusal. Parents were not permitted to receive Tdap vaccine without obtaining written informed consent but could receive Tdap vaccine without completing a survey. Parents were allowed to take the consent form home and return for study enrollment up until their child was aged 1 month. Tdap vaccine was provided at no charge and administered by clinic nursing staff. Parents receiving Tdap vaccine were provided a personal immunization record documenting receipt of the vaccine. The research coordinator queried the clinic database used for appointment scheduling and billing purposes to ascertain the number of newborns evaluated during the study period. The database and medical records were reviewed to obtain information about newborn’s race,
Study Population During the entire study period, 124 babies received medical care at the clinic. Parents of 22 (18%) babies were not approached for study participation due to the following reasons: nonavailability of the study coordinator (n ¼ 15), physician recommendation that the parents should not be approached for study participation (n ¼ 3), language barrier (n ¼ 3), not a regular clinic patient (n ¼ 1). Parents (n ¼ 200) of the remaining 102 (82%) babies, including 2 sets of twins, were approached for study participation. Nearly all mothers (97.0%) and most fathers (75.8%) were present at the first visit when approached by the study coordinator. Approximately two thirds (67.4%) of the mothers approached were aged between 30 and 49 years, whereas the remaining mothers were younger. Of newborns whose parents were approached for study participation, 2.9% were of Hispanic ethnicity, whereas the racial composition included 64.7% white, 18.6% Asian, 11.8% black, and 4.9% unknown. Newborns were mostly privately insured (84.3%), insured by Medicaid (12.7%), or uninsured (2.0%). Just under half of the newborns (49.0%) had an older sibling. Tdap Vaccine Coverage The study cohort for whom vaccine coverage rates are reported consists of 101 new mothers and 99 new fathers, including 1 same-sex couple. Twenty percent (40/200) of parents (24 mothers and 16 fathers) were considered ineligible for Tdap vaccination (Table 1), including 2 mothers with a history of seizures and 1 mother with a fever (generally considered a temporary exclusion). Two mothers (2%) and 3 fathers (3%) had already received Tdap vaccine. Of the remaining 160 parents eligible to receive Tdap vaccine, 82 (51.2%) parents (45 mothers and 37 fathers) received Tdap vaccine as part of the study. For 70 newborns, both parents were eligible to receive Tdap vaccine. Among these 70 parent pairs, in 27 (38.6%) both parents received vaccine, whereas in 29 (41.4%) and 14 (20.0%), neither parent and 1 parent received Tdap vaccine, respectively. For vaccine-eligible fathers, vaccine coverage was significantly higher if the father was present at the first encounter (61.0%) than if not present (4.2%); P < .0001. Of the 3 vaccine-eligible mothers not present at the first visit, none received Tdap vaccine. Receipt of Tdap vaccine by eligible parents was not significantly associated with the presence of an older sibling in the household, newborn race, or newborn ethnicity. Maternal age was not
346
Walter et al
ACADEMIC PEDIATRICS
Table 1. Tdap Exclusions and Tdap Coverage Among New Parents* New Mothers (n ¼ 101)
New Fathers (n ¼ 99)
Both Parents (N ¼ 200)
Tdap† exclusions/eligibility Td‡ <2 years Tdap previously Medical precaution Total Tdap exclusions Tdap eligible
19 (18.9) 2 (2.0) 3 (3.0) 24 (23.8) 77 (76.2)
13 (13.1) 3 (3.0) 0 (0.0) 16 (16.2) 83 (83.8)
32 (16.0) 5 (2.5) 3 (1.5) 40 (20.0) 160 (80.0)
Tdap coverage if eligible At first visit At subsequent visits Total
25 (32.5) 20 (26.0) 45 (58.5)
23 (27.7) 14 (16.9) 37 (44.6)
48 (30.0) 34 (21.2) 82 (51.2)
*Values are number (percentage). †Tdap ¼ tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccination. ‡Td ¼ tetanus and diphtheria vaccination.
significantly associated with receipt of Tdap vaccine in vaccine-eligible mothers. Although newborn health insurance status was not associated with Tdap vaccine receipt in eligible mothers, Tdap vaccine coverage was significantly greater among eligible fathers of newborns with private insurance (52.9%) when compared with fathers of newborns with Medicaid or no insurance (7.1%); P ¼ .002. Parent Survey The survey detailing reasons for Tdap vaccine refusal was completed by 7 parents refusing vaccination. Reasons cited included concerns about vaccine safety or side effects (n ¼ 3), fear of needles (n ¼ 2), belief that the vaccine was not going to help much (n ¼ 2), and not feeling well postcaesarean section delivery (n ¼ 1). One mother expressing concerns about vaccine safety was also worried about receiving Tdap vaccine while breast feeding. DISCUSSION In this study, just over half of eligible new parents seeking medical care for their newborns in the pediatric office agreed to receive Tdap vaccine. A large proportion (41%) of these parents elected to receive their dose of vaccine after a subsequent visit and not at the first visit. Some parents were overwhelmed at the initial pediatric office visit and were more focused on other issues related to caring for their newborn. Other parents elected to first determine when they had last received a Td vaccine prior to making a decision about receiving Tdap vaccine as part of the study. Generally an interval as short as 2 years between the most recent Td and administering Tdap vaccine is recommended, and our use of the 2-year interval between prior receipt of a Td and receiving Tdap vaccine in the office left a substantial portion of the newborn population unprotected from pertussis through the cocooning approach. Providers should be made aware that an interval shorter than 2 years may be used for postpartum women and new fathers, with no history of serious adverse reaction after a prior dose of tetanus and/or diphtheria toxoid-containing vaccine.8 The Tdap vaccine coverage rate after our intervention in the pediatric office setting was 58% among eligible
mothers, which is lower than a previously reported 80% coverage rate for new mothers vaccinated prior to hospital discharge in the postpartum period.8 Likewise, the observed vaccination rate of 51.2% for fathers and mothers of newborns seen in our study was lower than the 87% coverage rate reported for parents of high-risk infants in a neonatal intensive care unit.9 Administering Tdap vaccine prior to hospital discharge during the postpartum period would appear to be a more effective method of achieving higher Tdap coverage rates and earlier protection among postpartum women. However, this practice is not widely performed. Several inherent limitations exist in this study in terms of potential generalizability. The parent population was not very diverse, and the study was not powered to detect demographic differences with respect to Tdap vaccine acceptance. However, we did observe a higher Tdap coverage rate among new fathers present at the first visit or whose babies had private health care insurance. Because data were not routinely obtained on partner involvement or marital status, it is unclear if the health insurance coverage served as a proxy measure for other factors potentially associated with vaccination status. Additionally, since only 7 vaccine refusers elected to complete the survey, limited information was available about reasons for vaccine refusal. Despite the requirement for written informed consent, which potentially decreased Tdap vaccine acceptance, for numerous reasons our study results likely represent a best-case scenario for cocooning new parents in the office setting. This pediatric practice serves a highly educated parent population where both parents often attend pediatric visits. Tdap vaccine was provided at no charge, and insurance reimbursement for vaccine and vaccine administration was not sought. In addition, a dedicated study coordinator tracked parents during the infants’ first month of life. Cocooning in this setting was feasible, but it may not be feasible in other practice settings, particularly where fathers do not routinely accompany newborns to office visits. In assessing whether or not to vaccinate new parents with Tdap vaccine, office practices need to also consider several additional factors, including ordering and stocking additional vaccine, registration and billing processes, and providing proof of vaccination to the parent.
ACADEMIC PEDIATRICS
Tdap Immunization for New Parents in the Pediatric Office
Although postpartum Tdap vaccination among mothers prior to hospital discharge might achieve higher coverage in that population, this approach would not likely be inclusive of fathers. Thus, it remains unclear whether vaccinating new mothers in the hospital or vaccinating both parents in the office setting would be superior in terms of reducing overall risk for a given infant, and an optimal strategy may need to incorporate both approaches. Strategies to achieve more complete cocooning through paternal immunization need to be better delineated. As new fathers are not identified patients, consideration should be given to expansion of postpartum hospital programs to include fathers. Alternately, administering Tdap vaccine to new fathers in the pediatric office setting may be the best way to reach this population. Furthermore, until birthing hospitals establish postpartum vaccination programs, officebased vaccination may be an important alternative to increase maternal immunization rates. Additionally, providing information about Tdap vaccination during prenatal care visits might further enhance the success of both hospital-based and clinic-based Tdap vaccination programs of new parents. ACKNOWLEDGMENTS This work was supported by the Centers for Disease Control and Prevention in a cooperative agreement with Duke University (grant 5U01IP00074-02, Dr Emmanuel Walter, principal investigator). Data were presented in part at the 2008 Pediatric Academic Societies & Asian Society for Pediatric Research Joint Meeting, May 3–6, 2008, Honolulu, Hawaii.
347
REFERENCES 1. Centers for Disease Control and Prevention. Preventing tetanus, diphtheria, and pertussis among adults: use of tetanus toxoid, reduced diphtheria toxoid and acellular pertussis vaccine. Recommendations of the Advisory Committee on Immunization Practices (ACIP) and Recommendation of ACIP, supported by the Healthcare Infection Control Practices Advisory Committee (HICPAC) for use of Tdap among health-care personnel. Morbidity and Mortality Weekly Report Recomm Rep. 2006;55(RR-17):1–37. 2. Centers for Disease Control and Prevention. Summary of notifiable diseases–United States 2006. Morbidity and Mortality Weekly Report. 2008;55:1–100. 3. Tanaka M, Vitek CR, Pascual FB, et al. Trends in pertussis among infants in the United States, 1980–1999. JAMA. 2003;290:2968–2975. 4. Vitek CR, Pascual FB, Baughman AL, Murphy TV. Increase in deaths from pertussis among young infants in the United States in the 1990s. Pediatr Infect Dis J. 2003;22:628–634. 5. Bisgard KM, Pascual FB, Ehresmann KR, et al. Infant pertussis: who was the source? Pediatr Infect Dis J. 2004;23:985–989. 6. Wendelboe AM, Njamkepo E, Bourillon A, et al. Transmission of Bordetella pertussis to young infants. Pediatr Infect Dis J. 2007;26: 293–299. 7. Kowalzik F, Barbosa AP, Fernandes VR, et al. Prospective multinational study of pertussis infection in hospitalized infants and their household contacts. Pediatr Infect Dis J. 2007;26:238–242. 8. Centers for Disease Control and Prevention. Prevention of pertussis, tetanus, and diphtheria among pregnant and postpartum women and their infants: recommendations of the Advisory Committee on Immunization Practices (ACIP). Morbidity and Mortality Weekly Report. 2008;57 (RR-04). 9. Dylag AM, Shah SI. Administration of tetanus, diphtheria, and acellular pertussis vaccine to parents of high-risk infants in the neonatal intensive care unit. Pediatrics. 2008;122:e550–e555.
Results.—Two hundred parents were approached for study participation, of whom 40 (20%) were ineligible to receive Tdap vaccine primarily due to receipt of Td vaccine within the previous 2 years (32/40). Of the 160 eligible to receive Tdap vaccine, 82 (51.2%) received a dose. Although nearly 60% of vaccinated parents received Tdap vaccine the first time they were approached, over 40% received Tdap vaccine at a subsequent office visit occurring during the baby’s first month of life. Conclusions.—Offering Tdap vaccine in the pediatric office increases access to vaccination for both new fathers and mothers. When hospital-based, postpartum Tdap vaccination is not a routine practice, office-based vaccination of parents offers an option for protecting young infants.
S
The Centers for Disease Control and Prevention Advisory Committee on Immunization Practices emphasizes the importance of administering Tdap vaccine to adults who have or anticipate having close contact with an infant aged <12 months.1 The concept of vaccinating a baby’s close contacts and thereby interrupting transmission of disease to the infant has been termed a ‘‘cocoon’’ approach to preventing pertussis in the youngest children. New mothers who have not previously received Tdap vaccine should receive a dose during the immediate postpartum period. If Tdap vaccine is not administered to new mothers prior to hospital discharge, it should be administered promptly thereafter.8 New fathers and other adults in close contact with infants should ideally receive Tdap vaccine at least 2 weeks before beginning close contact with the infant. The purpose of this evaluation is to determine acceptance of a free Tdap vaccine when routinely offered to new parents in the pediatric office setting under ideal study conditions.
KEY WORDS: infants; pertussis; vaccine Academic Pediatrics 2009;9:344–7
ince the 1980s, the number of reported cases of pertussis in the United States increased dramatically. The first marked decline in disease was recorded during 2006, the year after licensure of Tdap (the tetanus toxoid, diphtheria toxoid, and acellular pertussis vaccine) for older children, adolescents, and adults in the United States.1,2 Increasing rates of pertussis have also been noted among infants aged 4 months and younger, who are at the highest risk of being hospitalized and suffering from complications secondary to pertussis.1,3,4 In many infant cases, the source of pertussis infection remains unknown. When identified, however, infant infection is most often acquired from a parent or older sibling.5–7 From the Primary Care Research Consortium, Duke University Medical Center, Durham, NC (Dr Walter, Dr Dolor, Ms Chmielewski); National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Ga (Dr Allred and Dr Kretsinger); and Immunization Branch, North Carolina Department of Health and Human Services, Raleigh, NC (Ms Rowe-West). Dr Walter is a speaker for Sanofi Pasteur and has served as a principal investigator for other clinical investigations sponsored by Sanofi Pasteur. The views in this article are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention, U.S. Department of Health and Human Services. Address correspondence to Emmanuel B. Walter, MD, MPH, Duke Children’s Primary Care Clinic, 4020 N Roxboro Rd, Durham, North Carolina 27704 (e-mail: [email protected]). Received for publication December 4, 2008; and in revised form May 13, 2009. accepted May 19, 2009. ACADEMIC PEDIATRICS Copyright Ó 2009 by Academic Pediatric Association
METHODS Study Design During a 5-month intervention period in 2007, parents of newborns whose medical care was initiated at a community-based, university-affiliated pediatric practice were routinely offered Tdap vaccine. The primary study outcome was Tdap vaccine coverage among parents of newborns. The study was conducted in a pediatric practice
344
Volume 9, Number 5 September–October 2009
ACADEMIC PEDIATRICS
Tdap Immunization for New Parents in the Pediatric Office
345
serving a highly educated parent population where both parents frequently attend their child’s medical appointments. Furthermore, a dedicated study coordinator tracked new parents, and Tdap vaccination was provided at no charge to the parent or insurance. Medical records of newborns presenting to the clinic during the study period were retrospectively reviewed to obtain newborn and parental demographic information.
ethnicity, insurance status, number of siblings, and mother’s age. Descriptive analyses were used to evaluate demographic characteristics of the newborns and mothers in addition to vaccine coverage rates. A Fisher exact test was used to assess the relationship between demographic characteristics and Tdap vaccine coverage. Analyses were conducted by using JMP version 7 (SAS Institute Inc, Cary, NC).
Study Population and Human Subjects The study population included parents whose newborns received medical care during the first month of life, including well-child care or weight- and feeding-related checkups, at the Duke Primary Care Clinic at Pickett Road, Durham, North Carolina. At the time this study was conducted, Tdap vaccine was not being routinely offered at local birthing hospitals, so new parents had not received Tdap vaccine in the peripartum period. The Institutional Review Board of Duke University Medical Center approved the research protocol.
RESULTS
Study Procedures Parents were introduced to the study by a clinic pediatrician or nurse and subsequently met with a research coordinator who further explained study procedures and provided a copy of the Tdap Vaccine Information Statement of the Centers for Disease Control and Prevention for review. Either parent alone or both parents could be present to be approached about study participation. Parents were asked to participate in the study, which involved receiving Tdap vaccine and completing a survey about reasons for Tdap vaccine refusal. Parents were screened for potential vaccine eligibility and were excluded from receiving Tdap vaccine if the following conditions were present: parental history of receipt of a prior Tdap vaccine or a tetanus and diphtheria vaccine (Td) within the preceding 2 years; a history of a bleeding disorder, Guillain-Barre´ syndrome, any ongoing neurological disorder, or fever in the preceding 24 hours; a life-threatening allergic reaction, a long seizure or coma within 7 days, or severe local limb swelling or pain after previously receiving a vaccine containing diphtheria toxoid, tetanus toxoid, or pertussis antigens. Parents were required to sign a written informed consent to either receive Tdap vaccine or to complete the survey about reasons for Tdap vaccine refusal. Parents were not permitted to receive Tdap vaccine without obtaining written informed consent but could receive Tdap vaccine without completing a survey. Parents were allowed to take the consent form home and return for study enrollment up until their child was aged 1 month. Tdap vaccine was provided at no charge and administered by clinic nursing staff. Parents receiving Tdap vaccine were provided a personal immunization record documenting receipt of the vaccine. The research coordinator queried the clinic database used for appointment scheduling and billing purposes to ascertain the number of newborns evaluated during the study period. The database and medical records were reviewed to obtain information about newborn’s race,
Study Population During the entire study period, 124 babies received medical care at the clinic. Parents of 22 (18%) babies were not approached for study participation due to the following reasons: nonavailability of the study coordinator (n ¼ 15), physician recommendation that the parents should not be approached for study participation (n ¼ 3), language barrier (n ¼ 3), not a regular clinic patient (n ¼ 1). Parents (n ¼ 200) of the remaining 102 (82%) babies, including 2 sets of twins, were approached for study participation. Nearly all mothers (97.0%) and most fathers (75.8%) were present at the first visit when approached by the study coordinator. Approximately two thirds (67.4%) of the mothers approached were aged between 30 and 49 years, whereas the remaining mothers were younger. Of newborns whose parents were approached for study participation, 2.9% were of Hispanic ethnicity, whereas the racial composition included 64.7% white, 18.6% Asian, 11.8% black, and 4.9% unknown. Newborns were mostly privately insured (84.3%), insured by Medicaid (12.7%), or uninsured (2.0%). Just under half of the newborns (49.0%) had an older sibling. Tdap Vaccine Coverage The study cohort for whom vaccine coverage rates are reported consists of 101 new mothers and 99 new fathers, including 1 same-sex couple. Twenty percent (40/200) of parents (24 mothers and 16 fathers) were considered ineligible for Tdap vaccination (Table 1), including 2 mothers with a history of seizures and 1 mother with a fever (generally considered a temporary exclusion). Two mothers (2%) and 3 fathers (3%) had already received Tdap vaccine. Of the remaining 160 parents eligible to receive Tdap vaccine, 82 (51.2%) parents (45 mothers and 37 fathers) received Tdap vaccine as part of the study. For 70 newborns, both parents were eligible to receive Tdap vaccine. Among these 70 parent pairs, in 27 (38.6%) both parents received vaccine, whereas in 29 (41.4%) and 14 (20.0%), neither parent and 1 parent received Tdap vaccine, respectively. For vaccine-eligible fathers, vaccine coverage was significantly higher if the father was present at the first encounter (61.0%) than if not present (4.2%); P < .0001. Of the 3 vaccine-eligible mothers not present at the first visit, none received Tdap vaccine. Receipt of Tdap vaccine by eligible parents was not significantly associated with the presence of an older sibling in the household, newborn race, or newborn ethnicity. Maternal age was not
346
Walter et al
ACADEMIC PEDIATRICS
Table 1. Tdap Exclusions and Tdap Coverage Among New Parents* New Mothers (n ¼ 101)
New Fathers (n ¼ 99)
Both Parents (N ¼ 200)
Tdap† exclusions/eligibility Td‡ <2 years Tdap previously Medical precaution Total Tdap exclusions Tdap eligible
19 (18.9) 2 (2.0) 3 (3.0) 24 (23.8) 77 (76.2)
13 (13.1) 3 (3.0) 0 (0.0) 16 (16.2) 83 (83.8)
32 (16.0) 5 (2.5) 3 (1.5) 40 (20.0) 160 (80.0)
Tdap coverage if eligible At first visit At subsequent visits Total
25 (32.5) 20 (26.0) 45 (58.5)
23 (27.7) 14 (16.9) 37 (44.6)
48 (30.0) 34 (21.2) 82 (51.2)
*Values are number (percentage). †Tdap ¼ tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccination. ‡Td ¼ tetanus and diphtheria vaccination.
significantly associated with receipt of Tdap vaccine in vaccine-eligible mothers. Although newborn health insurance status was not associated with Tdap vaccine receipt in eligible mothers, Tdap vaccine coverage was significantly greater among eligible fathers of newborns with private insurance (52.9%) when compared with fathers of newborns with Medicaid or no insurance (7.1%); P ¼ .002. Parent Survey The survey detailing reasons for Tdap vaccine refusal was completed by 7 parents refusing vaccination. Reasons cited included concerns about vaccine safety or side effects (n ¼ 3), fear of needles (n ¼ 2), belief that the vaccine was not going to help much (n ¼ 2), and not feeling well postcaesarean section delivery (n ¼ 1). One mother expressing concerns about vaccine safety was also worried about receiving Tdap vaccine while breast feeding. DISCUSSION In this study, just over half of eligible new parents seeking medical care for their newborns in the pediatric office agreed to receive Tdap vaccine. A large proportion (41%) of these parents elected to receive their dose of vaccine after a subsequent visit and not at the first visit. Some parents were overwhelmed at the initial pediatric office visit and were more focused on other issues related to caring for their newborn. Other parents elected to first determine when they had last received a Td vaccine prior to making a decision about receiving Tdap vaccine as part of the study. Generally an interval as short as 2 years between the most recent Td and administering Tdap vaccine is recommended, and our use of the 2-year interval between prior receipt of a Td and receiving Tdap vaccine in the office left a substantial portion of the newborn population unprotected from pertussis through the cocooning approach. Providers should be made aware that an interval shorter than 2 years may be used for postpartum women and new fathers, with no history of serious adverse reaction after a prior dose of tetanus and/or diphtheria toxoid-containing vaccine.8 The Tdap vaccine coverage rate after our intervention in the pediatric office setting was 58% among eligible
mothers, which is lower than a previously reported 80% coverage rate for new mothers vaccinated prior to hospital discharge in the postpartum period.8 Likewise, the observed vaccination rate of 51.2% for fathers and mothers of newborns seen in our study was lower than the 87% coverage rate reported for parents of high-risk infants in a neonatal intensive care unit.9 Administering Tdap vaccine prior to hospital discharge during the postpartum period would appear to be a more effective method of achieving higher Tdap coverage rates and earlier protection among postpartum women. However, this practice is not widely performed. Several inherent limitations exist in this study in terms of potential generalizability. The parent population was not very diverse, and the study was not powered to detect demographic differences with respect to Tdap vaccine acceptance. However, we did observe a higher Tdap coverage rate among new fathers present at the first visit or whose babies had private health care insurance. Because data were not routinely obtained on partner involvement or marital status, it is unclear if the health insurance coverage served as a proxy measure for other factors potentially associated with vaccination status. Additionally, since only 7 vaccine refusers elected to complete the survey, limited information was available about reasons for vaccine refusal. Despite the requirement for written informed consent, which potentially decreased Tdap vaccine acceptance, for numerous reasons our study results likely represent a best-case scenario for cocooning new parents in the office setting. This pediatric practice serves a highly educated parent population where both parents often attend pediatric visits. Tdap vaccine was provided at no charge, and insurance reimbursement for vaccine and vaccine administration was not sought. In addition, a dedicated study coordinator tracked parents during the infants’ first month of life. Cocooning in this setting was feasible, but it may not be feasible in other practice settings, particularly where fathers do not routinely accompany newborns to office visits. In assessing whether or not to vaccinate new parents with Tdap vaccine, office practices need to also consider several additional factors, including ordering and stocking additional vaccine, registration and billing processes, and providing proof of vaccination to the parent.
ACADEMIC PEDIATRICS
Tdap Immunization for New Parents in the Pediatric Office
Although postpartum Tdap vaccination among mothers prior to hospital discharge might achieve higher coverage in that population, this approach would not likely be inclusive of fathers. Thus, it remains unclear whether vaccinating new mothers in the hospital or vaccinating both parents in the office setting would be superior in terms of reducing overall risk for a given infant, and an optimal strategy may need to incorporate both approaches. Strategies to achieve more complete cocooning through paternal immunization need to be better delineated. As new fathers are not identified patients, consideration should be given to expansion of postpartum hospital programs to include fathers. Alternately, administering Tdap vaccine to new fathers in the pediatric office setting may be the best way to reach this population. Furthermore, until birthing hospitals establish postpartum vaccination programs, officebased vaccination may be an important alternative to increase maternal immunization rates. Additionally, providing information about Tdap vaccination during prenatal care visits might further enhance the success of both hospital-based and clinic-based Tdap vaccination programs of new parents. ACKNOWLEDGMENTS This work was supported by the Centers for Disease Control and Prevention in a cooperative agreement with Duke University (grant 5U01IP00074-02, Dr Emmanuel Walter, principal investigator). Data were presented in part at the 2008 Pediatric Academic Societies & Asian Society for Pediatric Research Joint Meeting, May 3–6, 2008, Honolulu, Hawaii.
347
REFERENCES 1. Centers for Disease Control and Prevention. Preventing tetanus, diphtheria, and pertussis among adults: use of tetanus toxoid, reduced diphtheria toxoid and acellular pertussis vaccine. Recommendations of the Advisory Committee on Immunization Practices (ACIP) and Recommendation of ACIP, supported by the Healthcare Infection Control Practices Advisory Committee (HICPAC) for use of Tdap among health-care personnel. Morbidity and Mortality Weekly Report Recomm Rep. 2006;55(RR-17):1–37. 2. Centers for Disease Control and Prevention. Summary of notifiable diseases–United States 2006. Morbidity and Mortality Weekly Report. 2008;55:1–100. 3. Tanaka M, Vitek CR, Pascual FB, et al. Trends in pertussis among infants in the United States, 1980–1999. JAMA. 2003;290:2968–2975. 4. Vitek CR, Pascual FB, Baughman AL, Murphy TV. Increase in deaths from pertussis among young infants in the United States in the 1990s. Pediatr Infect Dis J. 2003;22:628–634. 5. Bisgard KM, Pascual FB, Ehresmann KR, et al. Infant pertussis: who was the source? Pediatr Infect Dis J. 2004;23:985–989. 6. Wendelboe AM, Njamkepo E, Bourillon A, et al. Transmission of Bordetella pertussis to young infants. Pediatr Infect Dis J. 2007;26: 293–299. 7. Kowalzik F, Barbosa AP, Fernandes VR, et al. Prospective multinational study of pertussis infection in hospitalized infants and their household contacts. Pediatr Infect Dis J. 2007;26:238–242. 8. Centers for Disease Control and Prevention. Prevention of pertussis, tetanus, and diphtheria among pregnant and postpartum women and their infants: recommendations of the Advisory Committee on Immunization Practices (ACIP). Morbidity and Mortality Weekly Report. 2008;57 (RR-04). 9. Dylag AM, Shah SI. Administration of tetanus, diphtheria, and acellular pertussis vaccine to parents of high-risk infants in the neonatal intensive care unit. Pediatrics. 2008;122:e550–e555.