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Acceptability and Feasibility of Seasonal Influenza Vaccine Administration in an Antenatal Clinic Setting
OBSTETRICS OBSTETRICS
Acceptability and Feasibility of Seasonal Influenza Vaccine Administration in an Antenatal Clinic Setting Mark H. Yudin, MD, MSc,1 Maryam Salaripour, BSc, CIC, MPH,2 Michael D. Sgro, MD3 1
Department of Obstetrics and Gynaecology, St. Michael’s Hospital, University of Toronto, Toronto ON
2
Department of Risk Management and Quality Improvement, St. Michael’s Hospital, University of Toronto, Toronto ON
3
Department of Pediatrics, St. Michael’s Hospital, University of Toronto, Toronto ON
This work was presented at the 65th Annual Clinical Meeting of the Society of Obstetricians and Gynaecologists of Canada (SOGC), June 19, 2009, Halifax, NS.
Abstract
prénatale pendant une période de deux semaines à l’automne 2007 et sa seule tâche était de solliciter la participation des patientes et de leur offrir et de leur administrer le vaccin. La proportion des femmes ayant accepté le vaccin et les raisons de refus les plus courantes ont été déterminées.
Objective: To assess the acceptability and feasibility of administering seasonal influenza vaccinations in an antenatal clinic setting. Methods: All patients were approached during the study period by a dedicated nurse in the antenatal clinic and offered the seasonal influenza vaccine. The nurse was employed in the antenatal clinic for a two-week period in the fall of 2007 and had no tasks other than to approach patients and to offer and administer the vaccine. The proportion of women accepting the vaccine and the most common reasons for refusal were determined. Results: Not counting multiple visits by the same patient, there were 631 patient visits during the study period, and 266 (42%) women agreed to receive the vaccine. The most common reasons for refusal were already having received the vaccine or not wanting to be vaccinated during pregnancy. Conclusion: In Canada, most obstetricians do not administer vaccines in their offices. By implementing an influenza vaccination program in our antenatal clinic, we accomplished the immunization of almost one half of all patients seen during the study period. Prenatal care providers should routinely offer influenza vaccines as a means to increase vaccination rates among pregnant women.
Résumé Objectif : Évaluer l’acceptabilité et la faisabilité de l’administration d’un vaccin antigrippal saisonnier au sein d’une clinique prénatale. Méthodes : Au cours de la période d’étude, la participation de toutes les patientes a été sollicitée par une infirmière spécialisée au sein de la clinique prénatale et elles se sont vu offrir un vaccin antigrippal saisonnier. L’infirmière a été à l’emploi de la clinique
Key Words: Influenza, pregnancy, vaccination Competing Interests: None declared. Received on January 9, 2010 Accepted on February 25, 2010
Résultats : Sans compter les visites multiples d’une même patiente, 631 consultations de patiente ont été recensées au cours de la période d’étude et 266 (42 %) femmes ont consenti à recevoir le vaccin. Les raisons de refus les plus courantes étaient le fait d’avoir déjà reçu le vaccin ou le fait de ne pas souhaiter se faire vacciner pendant la grossesse. Conclusion : Au Canada, la plupart des obstétriciens n’administrent pas de vaccins au sein de leurs cabinets. En mettant en œuvre un programme de vaccination antigrippale au sein de notre clinique prénatale, nous sommes parvenus à immuniser près de la moitié de toutes les patientes reçues au cours de la période d’étude. Les fournisseurs de soins prénatals devraient systématiquement offrir une vaccination antigrippale à leurs patientes afin d’accroître les taux de vaccination chez les femmes enceintes. J Obstet Gynaecol Can 2010;32(8):745–748
INTRODUCTION
nfections with the influenza virus lead to annual epidemics of respiratory illness of varying severity worldwide in people of all ages. However, the risks for complications, hospitalizations, and deaths from influenza are higher among certain groups, such as persons aged 65 or older, persons of any age with underlying medical conditions, young children, and pregnant women.1 An increase in death rates associated with influenza among pregnant women was documented in the pandemics of 1916–1919 and 1957–1958 in the United States.2,3 In the recent H1N1 influenza pandemic, pregnant women were again found to be at an increased risk for hospitalization and death.4,5 Excess morbidity from influenza has also been found among pregnant women in interpandemic seasons.6,7
I
AUGUST JOGC AOÛT 2010 l
745
OBSTETRICS
Canadian data show that influenza-attributed hospitalization rates among pregnant women were 150/100 000 from 1994 to 2000, consistently higher than the rates among non-pregnant women.8 Immunization of women during pregnancy is advantageous to protect both the mother and the infant. The mother may benefit from prevention of severe disease, and the fetus or infant may benefit by acquiring antibodies in utero or by avoidance of exposure to an infected contact (the mother) after birth.9,10 National bodies in both Canada (the National Advisory Committee on Immunization) and the United States (the Centers for Disease Control and Prevention, and the Advisory Committee on Immunization Practices) recommend the vaccine for all pregnant women because of the increased risk for influenza-related complications.1,11 The ideal timing of vaccination in Canada is in October or November since epidemics of influenza usually occur during the winter months. There is no evidence that the vaccine is associated with adverse outcomes in pregnancy. Despite North American guidelines for influenza vaccination during pregnancy, it is unclear how many women are offered or actually receive the vaccine while pregnant. A 1999 survey of obstetricians and gynaecologists found that only 39% administered the influenza vaccine to obstetric patients, although 86% agreed that pregnant women’s risk for influenza-related morbidity and mortality increases during the last two trimesters.12 We have previously reported that the proportion of pregnant women in our population who had been offered the vaccine was only 19% in the current pregnancy and 21% in a previous pregnancy.13 In that study, only 55% of women believed that the vaccine was safe in pregnancy. Another study revealed that approximately one half of pregnant women surveyed were concerned about potential side effects from the vaccine and believed that it should be avoided during pregnancy.14 In Canada, most obstetricians do not administer vaccines in their offices, and pregnant women usually receive the vaccine from other sources such as family doctors, walk-in clinics, and public health sites. The primary objective of this study was to assess the acceptability and feasibility of administering the influenza vaccine in an obstetrician’s antenatal clinic setting, by determining the proportion of women who would accept the vaccine. The secondary objective was to determine the most common reasons for refusal of the vaccine. MATERIALS AND METHODS
The study took place in the antenatal clinic at St. Michael’s Hospital, which is a women’s health ambulatory care clinic in downtown Toronto serving a multi-ethnic patient population of varied socioeconomic status. 746
l AUGUST JOGC AOÛT 2010
All patients attending the clinic for a two-week period in the fall of 2007 (November 12 to 23) were approached by a study nurse. This time period was chosen to coincide with the timing of seasonal influenza vaccination in the community. The study nurse was employed during the study period and was dedicated to offering and administering the vaccine, with no other tasks. There was no sample size calculation performed for this study, and a sample size of convenience was used as all women attending the antenatal clinic during the study period were approached for participation. The proportion of women accepting the vaccine and the most common reasons for refusal were determined. Prior to initiation of the study, ethics approval was obtained from the St Michael’s Hospital Research Ethics Board. RESULTS
During the two-week study period, there were 631 unique patient visits (not counting multiple visits by the same patient). Of the 631 patients, 266 (42%) agreed to receive and were given the vaccine. There were no immediate adverse events in any patient. Among the 365 women who refused the vaccine, the most common reasons for refusal were either that the patient had already received the vaccine from another provider or that she did not wish to be vaccinated. DISCUSSION
In this study, by implementing a seasonal influenza vaccination program in our antenatal clinic, we were able to accomplish the vaccination of 42% of our patients in only a two-week period. This rate is approximately double the rate seen in our obstetrical population in a previous influenza season, when vaccination was not offered in our prenatal clinic.13 Pregnant women with influenza infection are at increased risk for complications compared to their non-pregnant peers, which may result from physiologic, mechanical, and hormonal alterations.15 This risk has been documented during both pandemic and interpandemic seasons. In the United States, an increase in death rates associated with influenza among pregnant women was noted in the pandemics of 1916–1919 and 1957–1958.2,3 In the recent H1N1 global pandemic, pregnant women were again over-represented among cases requiring hospitalization, intensive care unit admission, and death relative to the general population.4,5,16 In interpandemic seasons, the hospital admission rate in Canada for women with a respiratory condition during pregnancy was 150/100 000.8 In Tennessee, the rate for pregnant women in the third trimester was 250/100 000.17 These rates are equivalent to those estimated for Canadian adults aged 65 to 69 and 75 to 79, respectively.18
Acceptability and Feasibility of Seasonal Influenza Vaccine Administration in an Antenatal Clinic Setting
National bodies in Canada and the United States recommend universal influenza vaccination for pregnant women. Immunization of women during pregnancy is important because it offers protection to both the mother and the fetus or infant. In the pregnant woman, protection is conferred by helping to prevent the infection and its associated morbidity and mortality. However, vaccination of the mother can also protect the infant in two ways: by the passage of antibodies from the mother to the fetus during pregnancy, and by preventing infection in the mother and therefore decreasing the infant’s exposure risk after birth. Currently, seasonal influenza vaccination is recommended for all pregnant women in the United States by the Centers for Disease Control and Prevention and in Canada by the National Advisory Committee on Immunization.1,11 Despite North American guidelines for seasonal influenza vaccination during pregnancy, the majority of pregnant women are not immunized appropriately. The importance of vaccinating adult patients has traditionally been under-emphasized by obstetrician-gynaecologists.19 In a survey of Michigan obstetrician-gynaecologists, only 39% administered the influenza vaccine to obstetric patients.12 In a Canadian survey of maternity care providers, obstetricians were significantly less likely than family physicians to indicate that it was their responsibility to discuss, recommend, or provide influenza vaccinations.14 Further, they were more likely than family physicians to state that it was the local public health unit’s responsibility to vaccinate pregnant women.14 We have previously reported that the proportion of pregnant women in our population who had been offered the vaccine was only 19% in the current pregnancy and 21% in a previous pregnancy.12 Interestingly, studies have shown that prenatal care providers believe that influenza vaccination is safe and effective for pregnant women.12,14,20 Therefore, it does not appear that a lack of knowledge can account for a reluctance or unwillingness to vaccinate. However, other factors may play an important role in the likelihood of offering the vaccine. Provider knowledge and attitudes regarding vaccination may be influential, as those with more knowledge and better attitudes were significantly more likely to offer the vaccine to pregnant women in one study.14 In another study of non-physician staff in obstetric settings, only two thirds of respondents said they would recommend the seasonal influenza vaccine to pregnant women, reflecting a negative attitude toward the vaccine.20 Logistical issues may also play a role in the likelihood of offering and administering seasonal influenza vaccines in the offices of prenatal care providers. To provide vaccination services, providers must be able to properly store and handle the vaccines. Additional time is required for counselling and administration, and in busy
and crowded office settings, this may be difficult or not feasible. Finally, some obstetricians may feel that vaccination is better left to public health authorities or primary care providers.14 In our study, we employed a nurse for the study period to administer the vaccines. This nurse had no other duties, and was able to quickly and efficiently approach and vaccinate eligible and willing patients. Having a dedicated individual for this task is not feasible in most cases or outside of research settings. In addition to provider knowledge and attitudes, patient beliefs strongly influence the likelihood of accepting the vaccine. Vaccination rates are higher among women with better knowledge and attitudes.14 If pregnant women do not believe the vaccine is safe, they will not be willing to receive it even if it is available and offered. The vaccine is considered to be safe in all stages of pregnancy and during breastfeeding, and it has never been associated with an obvious pattern of serious side effects, congenital malformations, or adverse pregnancy outcomes.9,18 Unfortunately, a high proportion of women still believe that influenza vaccinations may not be safe during pregnancy or breastfeeding and that the vaccine has been associated with side effects or birth defects.13,14 Further, approximately half of pregnant women surveyed in one study were concerned about potential side effects from the vaccine and believed that it should be avoided during pregnancy.14 Education and knowledge transfer are crucial components of a successful seasonal influenza vaccination program for pregnant women. We have previously reported that with the use of an information pamphlet in our antenatal clinic we were able to double our seasonal influenza vaccination acceptance rates from one year to the next.21 This study was performed in the year before the recent H1N1 pandemic began. In the 2009–2010 influenza season, providing vaccines to pregnant women became even more urgent, as pregnant women were considered one of the priority populations for vaccination. Perhaps the additional media coverage and public health information campaigns will help to educate pregnant women further regarding the crucial importance of being immunized against both seasonal and pandemic forms of influenza during pregnancy. There are some limitations of our study. We only offered vaccines during a two-week period during influenza season. Perhaps we would have been able to accomplish a higher acceptance rate if we had been able to expand our program to the entire season. We did not collect any personal or demographic data on participants, so we were unable to stratify acceptance rates based on patient characteristics and these results may not be applicable to all populations. AUGUST JOGC AOÛT 2010 l
747
OBSTETRICS
CONCLUSION
In Canada, most obstetricians do not administer vaccines in their offices, and pregnant women usually receive the influenza vaccine from other sources such as family doctors, walk-in clinics, and public health sites. In our study, almost half of eligible women agreed to be vaccinated for seasonal influenza when the vaccine was offered in an obstetrician’s office. The most common reasons for refusal were that the patient had already received the vaccine from another provider or that she did not wish to be vaccinated. Future work should focus on the group not wishing to be vaccinated, exploring the reasons for this reluctance. With education and counselling, many of these women may ultimately elect to receive the vaccine. We must continue to emphasize the importance of influenza vaccination to our pregnant patients, and by offering it in prenatal care settings, we may be able to increase overall vaccine uptake rates. REFERENCES
9. France EK, Smith-Ray R, McClure D, Hambidge S, Xu S, Yamasaki K, et al. Impact of maternal influenza vaccination during pregnancy on the incidence of acute respiratory illness visits among infants. Arch Pediatr Adolesc Med 2006;160:1277–83. 10. Zaman K, Roy E, Arifeen SE, Rahman M, Raqib R, Wilson E, et al. Effectiveness of maternal influenza immunization in mothers and infants. N Engl J Med 2008;359(15):1555–64. 11. Public Health Agency of Canada. National Advisory Committee on Immunization (NACI) statement on influenza vaccination for the 2007–2008 season. CCDR 2007;33(ACS-7):1–38. 12. Gonik B, Jones T, Contreras D, Fasano N, Roberts C. Obstetrician-gynecologist’s role in vaccine-preventable diseases and immunization. Obstet Gynecol 2000;96:81–4. 13. Yudin MH, Salaripour M, Sgro MD. Pregnant women’s knowledge of influenza and the use and safety of the influenza vaccine during pregnancy. J Obstet Gynaecol Can 2009;31:120–5. 14. Tong A, Biringer A, Ofner-Agostini M, Upshur R, McGeer A. A cross-sectional study of maternity care providers’ and women’s knowledge, attitudes, and behaviours towards influenza vaccination during pregnancy. J Obstet Gynaecol Can 2008;30(5):404–10. 15. Rasmussen SA, Jamieson DJ, Bresee JS. Pandemic influenza and pregnant women. Emerg Infect Dis 2008;14:95–100.
1. Centers for Disease Control and Prevention. Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR 2004;53:1–40.
16. Jain S, Kamimoto L, Bramley AM, Schmitz AM, Benoit SR, Jouie J, et al. Hospitalized patients with 2009 H1N1 influenza in the United States, April-June 2009. N Engl J Med 2009;361:1935–44.
2. Harris JW. Influenza occurring in pregnant women: a statistical study of thirteen hundred and fifty cases. JAMA 1994;272:1133–7.
17. Neuzil K, Reed G, Mitchel E, Simonsen L, Griffin MR. Impact of influenza on acute cardiopulmonary hospitalizations in pregnant women. Am J Epidemiol 1998;148:1094–1102.
3. Widelock D, Csizmas L, Klein S. Influenza, pregnancy, and fetal outcome. Public Health Rep 1963;78:1–11. 4. Centers for Disease Control and Prevention. Novel influenza A (H1N1) virus infections in three pregnant women—United States, April-May 2009. MMWR 2009;58:497–500. 5. Jamieson DJ, Honein MA, Rasmussen SA, Williams JL, Swerdlow DL, Biggerstaff MS, et al. H1N1 2009 influenza virus infection during pregnancy in the USA. Lancet 2009;374:451–8. 6. Shahab SZ, Glezan WP. Influenza virus. In: Gonik B, ed. Viral Diseases in Pregnancy. New York: Springer-Verleg; 1994. p 215–23. 7. Irving WL, James DK, Stephenson T, Laing P, Jameson C, Oxford JS, et al. Influenza virus infection in the second and third trimesters of pregnancy: a clinical and seroepidemiological study. BJOG 2000;107:1282–9. 8. Schanzer DL, Langley JM, Tam TWS. Influenza-attributed hospitalization rates among pregnant women in Canada 1994–2000. J Obstet Gynaecol Can 2007;29:622–9.
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18. Schanzer DL, Langley JM, Tam TWS. Modelling the impact of influenza in Canada: a baseline for pandemic planning. In: Proceedings of the Second North American Congress of Epidemiology, Seattle, Washington, June 21–24, 2006. 19. Bartman BA, Weiss KB. Women’s primary care in the United States: a study of practice variation among physician specialties. J Womens Health 1993;2:261–8. 20. Broughton DE, Beigi RH, Switzer GE, Raker CA, Anderson BL. Obstetrics health care workers’ attitudes and beliefs regarding influenza vaccination in pregnancy. Obstet Gynecol 2009;114:981–7. 21. Yudin MH, Salaripour M, Sgro MD. Impact of patient education on knowledge of influenza and vaccine recommendations among pregnant women. J Obstet Gynaecol Can 2010;32:232–7.
Acceptability and Feasibility of Seasonal Influenza Vaccine Administration in an Antenatal Clinic Setting Mark H. Yudin, MD, MSc,1 Maryam Salaripour, BSc, CIC, MPH,2 Michael D. Sgro, MD3 1
Department of Obstetrics and Gynaecology, St. Michael’s Hospital, University of Toronto, Toronto ON
2
Department of Risk Management and Quality Improvement, St. Michael’s Hospital, University of Toronto, Toronto ON
3
Department of Pediatrics, St. Michael’s Hospital, University of Toronto, Toronto ON
This work was presented at the 65th Annual Clinical Meeting of the Society of Obstetricians and Gynaecologists of Canada (SOGC), June 19, 2009, Halifax, NS.
Abstract
prénatale pendant une période de deux semaines à l’automne 2007 et sa seule tâche était de solliciter la participation des patientes et de leur offrir et de leur administrer le vaccin. La proportion des femmes ayant accepté le vaccin et les raisons de refus les plus courantes ont été déterminées.
Objective: To assess the acceptability and feasibility of administering seasonal influenza vaccinations in an antenatal clinic setting. Methods: All patients were approached during the study period by a dedicated nurse in the antenatal clinic and offered the seasonal influenza vaccine. The nurse was employed in the antenatal clinic for a two-week period in the fall of 2007 and had no tasks other than to approach patients and to offer and administer the vaccine. The proportion of women accepting the vaccine and the most common reasons for refusal were determined. Results: Not counting multiple visits by the same patient, there were 631 patient visits during the study period, and 266 (42%) women agreed to receive the vaccine. The most common reasons for refusal were already having received the vaccine or not wanting to be vaccinated during pregnancy. Conclusion: In Canada, most obstetricians do not administer vaccines in their offices. By implementing an influenza vaccination program in our antenatal clinic, we accomplished the immunization of almost one half of all patients seen during the study period. Prenatal care providers should routinely offer influenza vaccines as a means to increase vaccination rates among pregnant women.
Résumé Objectif : Évaluer l’acceptabilité et la faisabilité de l’administration d’un vaccin antigrippal saisonnier au sein d’une clinique prénatale. Méthodes : Au cours de la période d’étude, la participation de toutes les patientes a été sollicitée par une infirmière spécialisée au sein de la clinique prénatale et elles se sont vu offrir un vaccin antigrippal saisonnier. L’infirmière a été à l’emploi de la clinique
Key Words: Influenza, pregnancy, vaccination Competing Interests: None declared. Received on January 9, 2010 Accepted on February 25, 2010
Résultats : Sans compter les visites multiples d’une même patiente, 631 consultations de patiente ont été recensées au cours de la période d’étude et 266 (42 %) femmes ont consenti à recevoir le vaccin. Les raisons de refus les plus courantes étaient le fait d’avoir déjà reçu le vaccin ou le fait de ne pas souhaiter se faire vacciner pendant la grossesse. Conclusion : Au Canada, la plupart des obstétriciens n’administrent pas de vaccins au sein de leurs cabinets. En mettant en œuvre un programme de vaccination antigrippale au sein de notre clinique prénatale, nous sommes parvenus à immuniser près de la moitié de toutes les patientes reçues au cours de la période d’étude. Les fournisseurs de soins prénatals devraient systématiquement offrir une vaccination antigrippale à leurs patientes afin d’accroître les taux de vaccination chez les femmes enceintes. J Obstet Gynaecol Can 2010;32(8):745–748
INTRODUCTION
nfections with the influenza virus lead to annual epidemics of respiratory illness of varying severity worldwide in people of all ages. However, the risks for complications, hospitalizations, and deaths from influenza are higher among certain groups, such as persons aged 65 or older, persons of any age with underlying medical conditions, young children, and pregnant women.1 An increase in death rates associated with influenza among pregnant women was documented in the pandemics of 1916–1919 and 1957–1958 in the United States.2,3 In the recent H1N1 influenza pandemic, pregnant women were again found to be at an increased risk for hospitalization and death.4,5 Excess morbidity from influenza has also been found among pregnant women in interpandemic seasons.6,7
I
AUGUST JOGC AOÛT 2010 l
745
OBSTETRICS
Canadian data show that influenza-attributed hospitalization rates among pregnant women were 150/100 000 from 1994 to 2000, consistently higher than the rates among non-pregnant women.8 Immunization of women during pregnancy is advantageous to protect both the mother and the infant. The mother may benefit from prevention of severe disease, and the fetus or infant may benefit by acquiring antibodies in utero or by avoidance of exposure to an infected contact (the mother) after birth.9,10 National bodies in both Canada (the National Advisory Committee on Immunization) and the United States (the Centers for Disease Control and Prevention, and the Advisory Committee on Immunization Practices) recommend the vaccine for all pregnant women because of the increased risk for influenza-related complications.1,11 The ideal timing of vaccination in Canada is in October or November since epidemics of influenza usually occur during the winter months. There is no evidence that the vaccine is associated with adverse outcomes in pregnancy. Despite North American guidelines for influenza vaccination during pregnancy, it is unclear how many women are offered or actually receive the vaccine while pregnant. A 1999 survey of obstetricians and gynaecologists found that only 39% administered the influenza vaccine to obstetric patients, although 86% agreed that pregnant women’s risk for influenza-related morbidity and mortality increases during the last two trimesters.12 We have previously reported that the proportion of pregnant women in our population who had been offered the vaccine was only 19% in the current pregnancy and 21% in a previous pregnancy.13 In that study, only 55% of women believed that the vaccine was safe in pregnancy. Another study revealed that approximately one half of pregnant women surveyed were concerned about potential side effects from the vaccine and believed that it should be avoided during pregnancy.14 In Canada, most obstetricians do not administer vaccines in their offices, and pregnant women usually receive the vaccine from other sources such as family doctors, walk-in clinics, and public health sites. The primary objective of this study was to assess the acceptability and feasibility of administering the influenza vaccine in an obstetrician’s antenatal clinic setting, by determining the proportion of women who would accept the vaccine. The secondary objective was to determine the most common reasons for refusal of the vaccine. MATERIALS AND METHODS
The study took place in the antenatal clinic at St. Michael’s Hospital, which is a women’s health ambulatory care clinic in downtown Toronto serving a multi-ethnic patient population of varied socioeconomic status. 746
l AUGUST JOGC AOÛT 2010
All patients attending the clinic for a two-week period in the fall of 2007 (November 12 to 23) were approached by a study nurse. This time period was chosen to coincide with the timing of seasonal influenza vaccination in the community. The study nurse was employed during the study period and was dedicated to offering and administering the vaccine, with no other tasks. There was no sample size calculation performed for this study, and a sample size of convenience was used as all women attending the antenatal clinic during the study period were approached for participation. The proportion of women accepting the vaccine and the most common reasons for refusal were determined. Prior to initiation of the study, ethics approval was obtained from the St Michael’s Hospital Research Ethics Board. RESULTS
During the two-week study period, there were 631 unique patient visits (not counting multiple visits by the same patient). Of the 631 patients, 266 (42%) agreed to receive and were given the vaccine. There were no immediate adverse events in any patient. Among the 365 women who refused the vaccine, the most common reasons for refusal were either that the patient had already received the vaccine from another provider or that she did not wish to be vaccinated. DISCUSSION
In this study, by implementing a seasonal influenza vaccination program in our antenatal clinic, we were able to accomplish the vaccination of 42% of our patients in only a two-week period. This rate is approximately double the rate seen in our obstetrical population in a previous influenza season, when vaccination was not offered in our prenatal clinic.13 Pregnant women with influenza infection are at increased risk for complications compared to their non-pregnant peers, which may result from physiologic, mechanical, and hormonal alterations.15 This risk has been documented during both pandemic and interpandemic seasons. In the United States, an increase in death rates associated with influenza among pregnant women was noted in the pandemics of 1916–1919 and 1957–1958.2,3 In the recent H1N1 global pandemic, pregnant women were again over-represented among cases requiring hospitalization, intensive care unit admission, and death relative to the general population.4,5,16 In interpandemic seasons, the hospital admission rate in Canada for women with a respiratory condition during pregnancy was 150/100 000.8 In Tennessee, the rate for pregnant women in the third trimester was 250/100 000.17 These rates are equivalent to those estimated for Canadian adults aged 65 to 69 and 75 to 79, respectively.18
Acceptability and Feasibility of Seasonal Influenza Vaccine Administration in an Antenatal Clinic Setting
National bodies in Canada and the United States recommend universal influenza vaccination for pregnant women. Immunization of women during pregnancy is important because it offers protection to both the mother and the fetus or infant. In the pregnant woman, protection is conferred by helping to prevent the infection and its associated morbidity and mortality. However, vaccination of the mother can also protect the infant in two ways: by the passage of antibodies from the mother to the fetus during pregnancy, and by preventing infection in the mother and therefore decreasing the infant’s exposure risk after birth. Currently, seasonal influenza vaccination is recommended for all pregnant women in the United States by the Centers for Disease Control and Prevention and in Canada by the National Advisory Committee on Immunization.1,11 Despite North American guidelines for seasonal influenza vaccination during pregnancy, the majority of pregnant women are not immunized appropriately. The importance of vaccinating adult patients has traditionally been under-emphasized by obstetrician-gynaecologists.19 In a survey of Michigan obstetrician-gynaecologists, only 39% administered the influenza vaccine to obstetric patients.12 In a Canadian survey of maternity care providers, obstetricians were significantly less likely than family physicians to indicate that it was their responsibility to discuss, recommend, or provide influenza vaccinations.14 Further, they were more likely than family physicians to state that it was the local public health unit’s responsibility to vaccinate pregnant women.14 We have previously reported that the proportion of pregnant women in our population who had been offered the vaccine was only 19% in the current pregnancy and 21% in a previous pregnancy.12 Interestingly, studies have shown that prenatal care providers believe that influenza vaccination is safe and effective for pregnant women.12,14,20 Therefore, it does not appear that a lack of knowledge can account for a reluctance or unwillingness to vaccinate. However, other factors may play an important role in the likelihood of offering the vaccine. Provider knowledge and attitudes regarding vaccination may be influential, as those with more knowledge and better attitudes were significantly more likely to offer the vaccine to pregnant women in one study.14 In another study of non-physician staff in obstetric settings, only two thirds of respondents said they would recommend the seasonal influenza vaccine to pregnant women, reflecting a negative attitude toward the vaccine.20 Logistical issues may also play a role in the likelihood of offering and administering seasonal influenza vaccines in the offices of prenatal care providers. To provide vaccination services, providers must be able to properly store and handle the vaccines. Additional time is required for counselling and administration, and in busy
and crowded office settings, this may be difficult or not feasible. Finally, some obstetricians may feel that vaccination is better left to public health authorities or primary care providers.14 In our study, we employed a nurse for the study period to administer the vaccines. This nurse had no other duties, and was able to quickly and efficiently approach and vaccinate eligible and willing patients. Having a dedicated individual for this task is not feasible in most cases or outside of research settings. In addition to provider knowledge and attitudes, patient beliefs strongly influence the likelihood of accepting the vaccine. Vaccination rates are higher among women with better knowledge and attitudes.14 If pregnant women do not believe the vaccine is safe, they will not be willing to receive it even if it is available and offered. The vaccine is considered to be safe in all stages of pregnancy and during breastfeeding, and it has never been associated with an obvious pattern of serious side effects, congenital malformations, or adverse pregnancy outcomes.9,18 Unfortunately, a high proportion of women still believe that influenza vaccinations may not be safe during pregnancy or breastfeeding and that the vaccine has been associated with side effects or birth defects.13,14 Further, approximately half of pregnant women surveyed in one study were concerned about potential side effects from the vaccine and believed that it should be avoided during pregnancy.14 Education and knowledge transfer are crucial components of a successful seasonal influenza vaccination program for pregnant women. We have previously reported that with the use of an information pamphlet in our antenatal clinic we were able to double our seasonal influenza vaccination acceptance rates from one year to the next.21 This study was performed in the year before the recent H1N1 pandemic began. In the 2009–2010 influenza season, providing vaccines to pregnant women became even more urgent, as pregnant women were considered one of the priority populations for vaccination. Perhaps the additional media coverage and public health information campaigns will help to educate pregnant women further regarding the crucial importance of being immunized against both seasonal and pandemic forms of influenza during pregnancy. There are some limitations of our study. We only offered vaccines during a two-week period during influenza season. Perhaps we would have been able to accomplish a higher acceptance rate if we had been able to expand our program to the entire season. We did not collect any personal or demographic data on participants, so we were unable to stratify acceptance rates based on patient characteristics and these results may not be applicable to all populations. AUGUST JOGC AOÛT 2010 l
747
OBSTETRICS
CONCLUSION
In Canada, most obstetricians do not administer vaccines in their offices, and pregnant women usually receive the influenza vaccine from other sources such as family doctors, walk-in clinics, and public health sites. In our study, almost half of eligible women agreed to be vaccinated for seasonal influenza when the vaccine was offered in an obstetrician’s office. The most common reasons for refusal were that the patient had already received the vaccine from another provider or that she did not wish to be vaccinated. Future work should focus on the group not wishing to be vaccinated, exploring the reasons for this reluctance. With education and counselling, many of these women may ultimately elect to receive the vaccine. We must continue to emphasize the importance of influenza vaccination to our pregnant patients, and by offering it in prenatal care settings, we may be able to increase overall vaccine uptake rates. REFERENCES
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