Sarah J. Clark et al 3 Table 1: Diﬀerences in obstetricians’ perceived responsibility for promoting or administering Tdap vaccine to adults in close contact with infants (P value compares responses of agree/strongly agree versus neutral/disagree/strongly disagree). Proportion of respondents who agree that obstetricians have responsibility for Promoting Tdap vaccine among adults in close contact with infants Administering Tdap vaccine to adults in close contact with infants I would likely recommend Tdap vaccine for women during pregnancy if recommended by ACIP/ACOG Agree/strongly agree Neutral/disagree/strongly disagree I would likely recommend Tdap vaccine for women immediately after delivery if recommended by ACIP/ACOG Agree/strongly agree Neutral/disagree/strongly disagree 77% 50% 85% 59% ≤ 6 months of age, assuming that an ACIP/ACOG recom- mendation would target this group. With regard to promot- ing Tdap vaccination, respondents perceived a shared re- sponsibility among obstetricians (72%), adult primary care providers (81%), pediatricians (68%), and public health providers (60%). With regard to administering Tdap vac- cine to adults likely to come in close contact with infants ≤ 6 months of age, respondents perceived a greater respon- sibility for adult primary care providers (89%) compared with obstetricians (62%), pediatricians (24%), and public health providers (61%). In bivariate analyses, those who were likely to recommend Tdap vaccine to postpartum or preg- nant women, if recommended by ACIP/ACOG, were more likely to perceive themselves as having a role in both promot- ing and administering Tdap vaccine to other adults likely to come in close contact with infants (Table 1). DISCUSSION In October 2005 the ACIP, with liaison representation from ACOG and other partners, voted to recommend that adults 19–64 years receive a single dose of Tdap vaccine to replace their next Td dose [4]. ACIP also voted to recommend that adults in close contact, or anticipating close contact, with an infant < 12 months of age (eg, parents, grandparents, childcare providers, and health care workers) receive a dose of Tdap as soon as feasible, if they have not previously re- ceived Tdap. The recommendation suggests an interval of 2 years since the most recent Td, although shorter intervals may be used. In addition, women planning a pregnancy and women in the immediate postpartum period are advised to receive Tdap if they have not previously done so. Pregnancy is not considered a contraindication to Tdap vaccination, and guidance on the use of Tdap during pregnancy was still un- der consideration by ACIP and ACOG. Results of this study, conducted prior to these recom- mendations, demonstrate that obstetricians will likely sup- < .001 — < .05 — 75% 60% 83% 68% < .001 — < .05 — port Tdap vaccination of obstetric patients if recommended by ACIP/ACOG. There appeared to be a slight preference for vaccination in the immediate postpartum period; still, the majority of respondents felt they would recommend vaccination during pregnancy, if endorsed in the future by ACIP/ACOG. This sentiment is consistent with prior re- search demonstrating that most obstetricians recommend inﬂuenza vaccination during pregnancy [5]. Note that the Fact Sheet included with this survey did state that there is no comprehensive information on the beneﬁts and risks of Tdap vaccination during pregnancy, as is true for other rec- ommended vaccines [6]. The factors inﬂuencing obstetricians’ perceived likeli- hood of recommending Tdap to pregnant or postpartum women, if recommended by ACIP/ACOG, are unclear. While it might be assumed that obstetricians who routinely admin- ister MMR and inﬂuenza vaccines would be more inclined to consider themselves likely to recommend Tdap vaccine, we did not ﬁnd that to be true in this study. In addition, per- ceived barriers to Tdap administration were not associated with predicted likelihood of recommending Tdap. Prior re- search has shown ACOG endorsement to be an important inﬂuence on obstetrician decisions about vaccination [7]. It is likely that practicing obstetricians expect the members of ACIP and ACOG to craft the most appropriate Tdap recom- mendations after reviewing the available evidence. Practice patterns for other vaccines can provide impor- tant clues to the uptake of new vaccines. Practices related to MMR vaccine for rubella nonimmune women in the post- partum period may provide the best analogy to the Tdap postpartum vaccination recommendation. In our study, 87% of obstetricians reported that they routinely administer MMR vaccine to postpartum mothers as indicated. However, logis- tical barriers to postpartum MMR vaccination remain; pre- vious studies have shown that a signiﬁcant proportion of ob- stetric practices do not stock MMR [7] and that a signiﬁcant proportion of hospitals do not have rubella immunization