Ilona Telefus Goldfarb, MD, MPH

Protecting pregnant women and their newborns by offering timely and effective vaccinations is a critical component of disease prevention, particularly given the rise of vaccine-preventable disease in the United States and around the globe. Studies show that when clinicians are knowledgeable about the benefits of vaccines and offer them to their patients, uptake of vaccination rises.

This is particularly true during pregnancy, when patients are concerned about vaccine safety and efficacy.

In this review, we provide an
	evidence-based summary of the vaccines that are recommended for women preconception, during pregnancy, and postpartum and provide counseling tips to help providers achieve the highest vaccine uptake rates possible.

The preconception period offers a unique opportunity to optimize a woman’s health for pregnancy and beyond. 


	Influenza infection during pregnancy has been associated with severe maternal illness, pregnancy loss, and preterm birth.

 Immunity confers significant benefits to both pregnant women and their offspring.

 Generally available for administration from late August through March of each year to correspond with the influenza season (timing may vary by region), the trivalent or quadrivalent, inactivated influenza vaccine should be given to all individuals older than age 6 months, including women considering pregnancy. Do not administer live vaccine (LAIV, Flumist) to women who may be pregnant but there is no contraindication to their family members receiving the live vaccine.


	Given the global measles outbreak, the Centers for Disease Control and Prevention (CDC) and American College of Obstetricians and Gynecologists (ACOG) recommend assessing measles immunity in addition to rubella immunity.

 The CDC recommends an evaluation of either a patient’s vaccine record or confirmatory measles serology to prove immunity (Table 1).

 While a single prior MMR dose may be adequate for some women, patients at high risk for exposure to measles should demonstrate proof of two doses. Many providers ask if the demonstration of rubella immunity from a prior pregnancy is adequate to confirm measles immunity. While rubella immunity is generally correlated with receipt of at least one MMR vaccine, that is not a valid surrogate for measles immunity. If the appropriate number of MMR doses has not been documented or the vaccine record is not available, measles serology can be obtained, and an MMR vaccine booster administered to patients with a negative Measles IgG antibody result. After receiving the MMR vaccine-a live, attenuated vaccine-women should wait 4 weeks prior to attempting pregnancy, given theoretical risks to the fetus with live vaccines.

 However, if pregnancy occurs inadvertently within the 4-week window, patients should be reassured that there have been no reports of fetal harm due to this exposure. 

Assessing rubella immunity has been a longstanding part of prenatal testing given the preventability of congenital rubella syndrome for those who have been adequately vaccinated with MMR. Therefore, women who are either measles non-immune or rubella non-immune should be vaccinated in the preconception period.  


	Given the significant risk of maternal and fetal harm with primary VZV infection during pregnancy, assessing a woman’s VZV immunity preconception will allow you to provide her with varicella vaccine if she is not immune. A history of chicken pox infection, evidence of VZV vaccination, or positive VZV serologies are all acceptable means to assess immunity.  For a woman without proof of immunity, a preconception VZV vaccine can protect her from life-threatening pneumonia and her fetus from congenital varicella syndrome. Because the vaccine for VZV is live attenuated, vaccination should be performed, at least 4 weeks prior to attempted conception given the theoretical concern for causing birth defects.

Other vaccines may be indicated, particularly in women who have medical illnesses that put them at high risk for
	vaccine-preventable illnesses. Obtaining a thorough preconception immunization history as part of routine care also may uncover adult women who have missed prior vaccination opportunities. 

Hepatitis B (HPV) and hepatitis A (HAV) 


	HAB and HAV immunity is particularly important for women planning pregnancy who are at high risk for these infections (Table 2). HBV vaccine is administered in a three-dose series (0, 1, and 4 months apart). The vaccine for HAV is inactivated and can be given pre-exposure as a two-dose series (6 to 18 months apart), or as post-exposure prophylaxis. These vaccines are recombinant and have not been associated with adverse fetal outcomes. Therefore, no waiting period is required after administration in the preconception period and they can be administered during pregnancy if needed or if the three-dose series has not been completed.


	The pneumococcal vaccine is indicated for adult women who are at high risk for serious complications from pneumococcus, such as individuals who smoke or who have asthma or diabetes.  Additional indications are summarized in Table 2.

 There are two pneumococcal vaccines. For adults with risk factors, the CDC recommends administering one dose of PCV13 followed by the PPSV23 dose at least 8 weeks later without a delay in conception.


	Vaccination against HPV is recommended to prevent new HPV infections and HPV-associated diseases, including cervical cancer. While this vaccine remains targeted to young adolescents, the Advisory Committee on Immunization Practices (ACIP) now endorses catch-up HPV vaccination for all individuals through age 26 years. Adults who have previously been infected with one or more HPV types can still benefit from protection for other types available in the vaccine. For adults aged 27 through 45 years, and at risk for new HPV infection, decisions around vaccination should be made using a shared clinical decision-making model

 HPV vaccination for patients older than age 15 should follow a three-dose regimen (0, 1 to 2 and 6 months). Counseling and guidance about the benefits of HPV vaccination are ideal for preconception women who plan for pregnancy in greater than 6 months. While the HPV vaccine is not recommended during pregnancy, inadvertent HPV vaccination during pregnancy is not associated with adverse events for a woman or her fetus.


	Incorporating vaccine administration as a routine part of prenatal care is key to protecting pregnant women and their offspring from vaccine-preventable diseases. Evidence-based strategies to build a robust vaccination program embedded within an obstetrical practice include: staff education for all individuals who encounter the patient (front desk, medical assistants, lab techs, nurses, midwives, and physicians), patient education in multiple languages, and standing-order sets.

When vaccines are not available within your office or clinic, encouraging women to receive needed vaccines at the pharmacy or through their employer is also important, but a less effective strategy. 

Vaccines that should be given to every pregnant woman during every pregnancy include influenza during flu season and Tdap.

 As noted previously, other vaccines may be given if women have high-risk comorbidities or are midway through a vaccine series. HAV, HAB, and the pneumococcal vaccine should be considered for administration during pregnancy based on a patient’s medical history and additional risk factors (Table 3). Obstetrical providers  who are knowledgeable about vaccine safety and efficacy and prepared to debunk myths about vaccines in pregnancy will have the highest rates of vaccine uptake (Table 4).


	Attention to vaccination continues as we care for women in the postpartum period. All women who are found to be rubella, measles, or VZV non-immune during pregnancy should receive these live-attenuated virus vaccines postpartum without concerns about lactation. Postpartum and lactating women who are age 26 or younger and who have not previously received HPV vaccination should have this series initiated. The vaccine may also be considered for women older than age 26 who are at risk for HPV exposure.

 Finally, postpartum and lactating women with risk factors (Table 2) who have not previously been vaccinated should receive HAV, HBV, and pneumococcal vaccines according to ACOG and CDC recommendations. 

Finney Rutten LJ, St Sauver JL, Beebe TJ, et al. Association of both consistency and strength of self-reported clinician recommendation for HPV vaccination and HPV vaccine uptake among 11- to 12-year-old children. 

Rutten LJF, St Sauver JL, Beebe TJ, et al. Clinician knowledge, clinician barriers, and perceived parental barriers regarding human papillomavirus vaccination: Association with initiation and completion rates. 

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ACOG Committee Opinion No. 732: Influenza Vaccination During Pregnancy. 

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Measles & the MMR Vaccine: Recommendations Around Pregnancy, Including the Periconception and Postpartum Periods - UW Medicine Provider Resource. 

http://providerresource.uwmedicine.org/flexpaper/measles-and-the-mmr-vaccine-recommendations-around-pregnancy-including-the-periconception-and-postpartum-periods

Centers for Disease Control and Prevention. Measles: Evidence of Immunity. 

https://www.cdc.gov/measles/hcp/index.html#immunity

McLean HQ, Fiebelkorn AP, Temte JL, et al. Centers for Disease Control and Prevention. Prevention of measles, rubella, congenital rubella syndrome, and mumps, 2013: summary recommendations of the Advisory Committee on Immunization Practices (ACIP). 

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American College of Obstetricians and Gynecologists. ACOG Practice Bulletin No. 86: Viral hepatitis in pregnancy. 

Mast EE, Weinbaum CM, Fiore AE, et al. A comprehensive immunization strategy to eliminate transmission of hepatitis B virus infection in the United States: recommendations of the Advisory Committee on Immunization Practices (ACIP) Part II: immunization of adults. 

Fiore AE, Wasley A, Bell BP. Prevention of hepatitis A through active or passive immunization: recommendations of the Advisory Committee on Immunization Practices (ACIP). 

Centers for Disease Control and Prevention (CDC). Use of 13-valent pneumococcal conjugate vaccine and 23-valent pneumococcal polysaccharide vaccine for adults with immunocompromising conditions: recommendations of the Advisory Committee on Immunization Practices (ACIP). 

Centers for Disease Control and Prevention (CDC), Advisory Committee on Immunization Practices. Updated recommendations for prevention of invasive pneumococcal disease among adults using the 23-valent pneumococcal polysaccharide vaccine (PPSV23). 

Pneumococcal Vaccination Summary | Who and When to Vaccinate | For Providers | CDC. 

https://www.cdc.gov/vaccines/vpd/pneumo/hcp/who-when-to-vaccinate.html

. Published June 20, 2019. Accessed September 25, 2019.

HPV Vaccine Recommendations | Human Papillomavirus | CDC. 

https://www.cdc.gov/vaccines/vpd/hpv/hcp/recommendations.html

. Published June 27, 2019. Accessed September 25, 2019.

Committee Opinion No. 704 Summary: Human Papillomavirus Vaccination. 

Use of Standing Orders Programs to Increase Adult Vaccination Rates:  Recommendations of the Advisory Committee on Immunization Practices. 

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Committee on Obstetric Practice, Immunization and Emerging Infections Expert Work Group. Committee Opinion No. 718: Update on Immunization and Pregnancy: Tetanus, Diphtheria, and Pertussis Vaccination. 

ACOG Committee Opinion No. 741: Maternal Immunization. 

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Ilona Telefus Goldfarb, MD, MPH

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