Influenza and Pertussis Vaccination Among Pregnant Women
Influenza and Pertussis Vaccination Among Pregnant Women
In this survey of postpartum mothers, we found relatively high percentages reporting receipt of influenza and Tdap vaccines for themselves, with 67% reporting having received both vaccines. Additionally, about 6 of 10 and 7 of 10 of these mothers reported that at least 1 close contact of their newborn had been vaccinated against influenza and pertussis, respectively, which we defined as "cocooning." Mothers reported generally greater perceived benefits from Tdap vaccine than from influenza vaccine. However, close to one-half had general concerns about vaccine safety. About two-thirds of respondents reported having received a recommendation from their obstetrician for both influenza vaccine and Tdap vaccine, and about half had received recommendations regarding cocooning. Cocooning was associated with several psychological domains corresponding to attitudes about vaccination and importantly also with a recommendation to be vaccinated from the obstetrician. For Tdap but not influenza vaccine, cocooning was negatively associated with Hispanic race, a finding that is difficult to explain based on our study but which requires further explanation.
A striking finding from our study was the association of maternal receipt of vaccination with the receipt of vaccination of newborn's close contacts, which we found for both influenza and pertussis vaccination. Approximately 3 times as many infants' close contacts were vaccinated among mothers who got these vaccines when compared with mothers who did not receive these vaccines. While there is likely some degree of reporting bias in this finding, it could suggest that mothers strongly influence the rest of the household when it comes to vaccination. However, it is also possible that these mothers were simply from households with a strong culture of vaccination, so that they were influenced by the household rather than vice versa. The findings from the multivariable model were consistent with the idea of the mother influencing the household: provider recommendation was known to be associated with maternal receipt of vaccine, and in our study, it was also associated with vaccination of their infants' close contacts. This finding has important implications: while there has been significant effort at trying to vaccinate the close contacts of newborn infants, whether in hospitals or in pediatricians' offices, resources and educational efforts may be better allocated to educating mothers who are hesitant to be vaccinated of the benefits and safety of vaccination. One might posit that once they are convinced of the importance of vaccination, they would then do the work of making sure that other close contacts of their newborn are also vaccinated.
The findings of our multivariable models help inform potential educational messages for pregnant women. While it is not surprising that higher perceived susceptibility to infection and lower perceived barriers to vaccination were associated with cocooning for both vaccines, the strongest association for influenza vaccine, greater even than obstetrician recommendation, was high perceived benefits to vaccination. This is consistent with the findings of a study from the 2012–2013 influenza season, which found that among pregnant women who received a recommendation from a health care provider and were offered influenza vaccine but refused it, the most common concerns were that the vaccine would cause influenza, safety risk to the baby and not believing that the vaccination was effective. The implication is that educational efforts and interventions among pregnant women regarding influenza vaccine could be focused on increasing the understanding of the benefits of vaccination to the newborn infant and its safety during pregnancy.
Because more women in the US are receiving prenatal care from advanced practitioners such as nurse midwives, physician assistants and nurse practitioners, our study results suggest that educational efforts aimed at increasing vaccination among pregnant women should be focused not only on obstetricians but also on advanced practitioners. In this study, pregnant women were more likely to have received recommendations for vaccination and cocooning specifically from obstetricians than from advanced practitioners. It is possible that our sample reported this simply because they saw obstetricians more often than advanced practitioners, so this finding should be considered hypothesis-generating rather than conclusive. Nonetheless, most of the prior studies regarding attitudes about vaccination in pregnancy have been among obstetricians themselves, with little exploration of attitudes of advanced practitioners. Educational efforts targeted at advanced practitioners and ancillary staff could increase the frequency of vaccine recommendations, promoting a "culture of vaccination" within the obstetrical setting.
Women in our study reported multiple settings for influenza and Tdap vaccination, with the obstetrics provider's office the most common site for influenza vaccination and the hospital after delivery the most common site for Tdap vaccination. Our study was conducted for about 1 year after the recommendation to give Tdap vaccination in pregnancy, suggesting that many providers were still not stocking Tdap vaccine at the time of the survey but rather relying on the delivering hospitals to provide it. Providers who do not stock these vaccines should consider that recommending a vaccine, while important, is not enough: they must stock and administer it as well, as women whose providers do not stock vaccine are less likely to receive it. Providers may still be concerned about the financial and logistical barriers associated with stocking and administering vaccines. However, these barriers have decreased as the Affordable Care Act requires first dollar coverage (no copay) for all the Advisory Committee on Immunization Practices-recommended vaccines. Providers can access resources to aid them in providing vaccines, such as the toolkits created by the American College of Obstetrics and Gynecology for vaccination within OB/GYN practices.
This study had several limitations. First, the respondents may have been more likely to have more favorable attitudes toward vaccination than nonrespondents. Also, vaccination status was based on self-report and may not have been accurate, particularly when reporting for the close contacts of newborns. Moreover, the high reported rates of vaccination may reflect social desirability bias. An additional limitation is that the study population was exclusively English-speaking as well as relatively well-educated and affluent, which is very likely to limit its generalizability. In addition, the finding of a negative association of Hispanic race with cocooning may have resulted from this sample bias. Sample bias or the broader availability of influenza vaccine may also account for the finding that influenza vaccine was more acceptable than Tdap among Hispanics, which contradicts previous experience.
This study confirms the findings of prior studies about the importance of obstetrician recommendation to pregnant women to receive vaccines and adds to the literature that that influence applies to the vaccination of close contacts as well. Close contacts of newborns are also more likely to be vaccinated if the mother herself is vaccinated, suggesting that educational efforts regarding the importance of cocooning newborns may best be directed at pregnant women. Future educational interventions should be directed at addressing identified barriers to vaccination and stressing the benefits of vaccination, particularly for influenza vaccine.
Discussion
In this survey of postpartum mothers, we found relatively high percentages reporting receipt of influenza and Tdap vaccines for themselves, with 67% reporting having received both vaccines. Additionally, about 6 of 10 and 7 of 10 of these mothers reported that at least 1 close contact of their newborn had been vaccinated against influenza and pertussis, respectively, which we defined as "cocooning." Mothers reported generally greater perceived benefits from Tdap vaccine than from influenza vaccine. However, close to one-half had general concerns about vaccine safety. About two-thirds of respondents reported having received a recommendation from their obstetrician for both influenza vaccine and Tdap vaccine, and about half had received recommendations regarding cocooning. Cocooning was associated with several psychological domains corresponding to attitudes about vaccination and importantly also with a recommendation to be vaccinated from the obstetrician. For Tdap but not influenza vaccine, cocooning was negatively associated with Hispanic race, a finding that is difficult to explain based on our study but which requires further explanation.
A striking finding from our study was the association of maternal receipt of vaccination with the receipt of vaccination of newborn's close contacts, which we found for both influenza and pertussis vaccination. Approximately 3 times as many infants' close contacts were vaccinated among mothers who got these vaccines when compared with mothers who did not receive these vaccines. While there is likely some degree of reporting bias in this finding, it could suggest that mothers strongly influence the rest of the household when it comes to vaccination. However, it is also possible that these mothers were simply from households with a strong culture of vaccination, so that they were influenced by the household rather than vice versa. The findings from the multivariable model were consistent with the idea of the mother influencing the household: provider recommendation was known to be associated with maternal receipt of vaccine, and in our study, it was also associated with vaccination of their infants' close contacts. This finding has important implications: while there has been significant effort at trying to vaccinate the close contacts of newborn infants, whether in hospitals or in pediatricians' offices, resources and educational efforts may be better allocated to educating mothers who are hesitant to be vaccinated of the benefits and safety of vaccination. One might posit that once they are convinced of the importance of vaccination, they would then do the work of making sure that other close contacts of their newborn are also vaccinated.
The findings of our multivariable models help inform potential educational messages for pregnant women. While it is not surprising that higher perceived susceptibility to infection and lower perceived barriers to vaccination were associated with cocooning for both vaccines, the strongest association for influenza vaccine, greater even than obstetrician recommendation, was high perceived benefits to vaccination. This is consistent with the findings of a study from the 2012–2013 influenza season, which found that among pregnant women who received a recommendation from a health care provider and were offered influenza vaccine but refused it, the most common concerns were that the vaccine would cause influenza, safety risk to the baby and not believing that the vaccination was effective. The implication is that educational efforts and interventions among pregnant women regarding influenza vaccine could be focused on increasing the understanding of the benefits of vaccination to the newborn infant and its safety during pregnancy.
Because more women in the US are receiving prenatal care from advanced practitioners such as nurse midwives, physician assistants and nurse practitioners, our study results suggest that educational efforts aimed at increasing vaccination among pregnant women should be focused not only on obstetricians but also on advanced practitioners. In this study, pregnant women were more likely to have received recommendations for vaccination and cocooning specifically from obstetricians than from advanced practitioners. It is possible that our sample reported this simply because they saw obstetricians more often than advanced practitioners, so this finding should be considered hypothesis-generating rather than conclusive. Nonetheless, most of the prior studies regarding attitudes about vaccination in pregnancy have been among obstetricians themselves, with little exploration of attitudes of advanced practitioners. Educational efforts targeted at advanced practitioners and ancillary staff could increase the frequency of vaccine recommendations, promoting a "culture of vaccination" within the obstetrical setting.
Women in our study reported multiple settings for influenza and Tdap vaccination, with the obstetrics provider's office the most common site for influenza vaccination and the hospital after delivery the most common site for Tdap vaccination. Our study was conducted for about 1 year after the recommendation to give Tdap vaccination in pregnancy, suggesting that many providers were still not stocking Tdap vaccine at the time of the survey but rather relying on the delivering hospitals to provide it. Providers who do not stock these vaccines should consider that recommending a vaccine, while important, is not enough: they must stock and administer it as well, as women whose providers do not stock vaccine are less likely to receive it. Providers may still be concerned about the financial and logistical barriers associated with stocking and administering vaccines. However, these barriers have decreased as the Affordable Care Act requires first dollar coverage (no copay) for all the Advisory Committee on Immunization Practices-recommended vaccines. Providers can access resources to aid them in providing vaccines, such as the toolkits created by the American College of Obstetrics and Gynecology for vaccination within OB/GYN practices.
This study had several limitations. First, the respondents may have been more likely to have more favorable attitudes toward vaccination than nonrespondents. Also, vaccination status was based on self-report and may not have been accurate, particularly when reporting for the close contacts of newborns. Moreover, the high reported rates of vaccination may reflect social desirability bias. An additional limitation is that the study population was exclusively English-speaking as well as relatively well-educated and affluent, which is very likely to limit its generalizability. In addition, the finding of a negative association of Hispanic race with cocooning may have resulted from this sample bias. Sample bias or the broader availability of influenza vaccine may also account for the finding that influenza vaccine was more acceptable than Tdap among Hispanics, which contradicts previous experience.
This study confirms the findings of prior studies about the importance of obstetrician recommendation to pregnant women to receive vaccines and adds to the literature that that influence applies to the vaccination of close contacts as well. Close contacts of newborns are also more likely to be vaccinated if the mother herself is vaccinated, suggesting that educational efforts regarding the importance of cocooning newborns may best be directed at pregnant women. Future educational interventions should be directed at addressing identified barriers to vaccination and stressing the benefits of vaccination, particularly for influenza vaccine.
