Safety and Immunogenicity of Simultaneous Tdap and IIV in Pregnant Women

Inclusion Criteria:

1. Pregnant, as determined by medical history; 18 - 45 years of age inclusive

2. Intention of receiving Tdap and IIV vaccines based on Advisory Committee onImmunization Practices (ACIP) recommendations

3. Willing to provide written informed consent prior to initiation of any studyprocedures

4. Singleton gestation ≥ 26 weeks 0 days gestation - ≤32 weeks 0 days gestation at thetime of Visit 1 vaccination based on reconciliation of last menstrual period andultrasound dating. Estimated due date (EDD) and Gestational Age (GA) - EDD will bebased on reconciliation of a "sure" first day of the last menstrual period (LMP) andearliest dating ultrasound. If the LMP is uncertain, then the earliest datingultrasound will be used to determine EDD and GA. If the ultrasound derived-EDD is inagreement with sure-LMP derived EDD, then the LMP-derived EDD is used to determineGA. If the ultrasound derived EDD is not in agreement with the LMP-derived EDD, theultrasound-derived EDD is used to determine GA.

5. English or Spanish literate

6. Intention of being available for entire study period and complete all relevant studyprocedures, including follow-up phone calls and collection of delivery information.

Exclusion Criteria:

1. For subjects enrolling during the 2016-2017 influenza season: IIV/LAIV receiptduring 2016-2017 influenza season prior to study enrollment

2. For subjects enrolling during the 2017-2018 influenza season: IIV/LAIV receiptduring 2017-2018 influenza season prior to study enrollment

3. Tdap/Td/TT receipt during current pregnancy prior to study enrollment 3. Hasimmunosuppression as a result of an underlying illness or treatment, or use ofanti-cancer chemotherapy or radiation therapy within the preceding 36 months.

4. Has an active neoplastic disease (excluding non-melanoma skin cancer), ahistory of any hematologic malignancy, current bleeding disorder, or takinganticoagulants (daily low dose aspirin may be acceptable).

5. Has a history of receiving immunoglobulin or other blood product (withexception of Rhogam) within the 3 months prior to enrollment in this study.

6. Known to have pre-existing diabetes mellitus or an autoimmune disorder. 7.Febrile illness within the last 24 hours or an oral temperature >/= 100.4°F (>/= 38.0°C) prior to IIV or Tdap administration 8. Contraindication to IIVreceipt including history of severe allergic reaction after a previous dose ofany influenza vaccine; or to a vaccine component, including egg protein 9.Contraindication to Tdap receipt including history of severe allergic reactionafter a previous dose of any tetanus toxoid-, diphtheria toxoid-, or pertussisantigen-containing vaccine or encephalopathy within 7 days of administration ofa previous dose of a pertussis antigen-containing vaccine that is notattributable to another identifiable cause 10. Arthus-type hypersensitivityreaction following a prior dose of a tetanus toxoid-containing vaccine withinthe last 10 years 11. Any condition that may interfere with assessment of localinjection site reactions, e.g. lymphadenectomy or obscuring tattoos 12. Historyof Guillain-Barré syndrome within 6 weeks of a prior dose of any tetanustoxoid-, diphtheria toxoid- or pertussis antigen-containing vaccine orinfluenza vaccine 13. Known or suspected impairment of immunologic functionincluding infection with HIV, hepatitis B or C 14. Use of immunosuppressive orcytotoxic drugs except receipt of oral or parenteral (intravenous, subcutaneousor intramuscular) corticosteroids 30 or more days prior to enrollment. Personswho have used oral or parenteral corticosteroids within 12 months prior toenrollment may be enrolled if the longest course of therapy was less than 14consecutive days and no dose was given within 30 days of enrollment.Intraarticular, bursal, tendon, or epidural injections of corticosteroids arepermissible if the most recent injection was 30 or more days prior toenrolment. Persons applying topically corticosteroid in either upper arm (i.e.injection site) may be enrolled 1 or more days after their therapy iscompleted. Corticosteroids administered topically at non-injection sites, byinhalation or intranasally are permissible 15. Receipt of any licensed vaccinewithin 14 days prior to study vaccination or planning receipt of any vaccines (except study vaccines) prior to Visit 7 follow up.

7. Receipt of live vaccine during current pregnancy. 17. High risk for pretermbirth (active preterm labor, short cervix, cervical cerclage, receipt ofantenatal corticosteroids for fetal lung maturity prior to Visit 1) 18.Antenatal ultrasound diagnosis of fetal growth restriction, defined as < 10thpercentile estimated fetal weight for gestational age 19. Known fetalcongenital anomaly, e.g. genetic abnormality or malformation based on antenatalultrasound 20. Any condition which, in the opinion of the investigators, maypose a health risk to the subject or interfere with the evaluation of the studyobjectives.

8. Anyone who is a relative of any research study personnel 22. Anyone who is anemployee of any research study personnel 23. Anyone who is already enrolled orplans to enroll in another clinical trial with an investigational product.Co-enrollment in observational or behavioral intervention studies are allowedat any time.

9. Previous participation in the study.