Addressing Immunizations in Pregnant and Lactating Women

The immunization status of pregnant and lactating women should be routinely assessed, and indicated vaccines should be recommended.¹ Patients may choose not to get vaccinated for a variety of reasons including short-term and long-term safety concerns, moral grounds or religious beliefs, cost, amount of injections, and lack of knowledge.² A complete review of vaccine safety is beyond the scope of this article; however, all vaccine providers should be aware of the public perception as well as expert opinion in order help patients make evidence-based decisions. Additionally, some resources to aid clinicians in vaccine administration are listed in the table.

During the 2015-2016 flu season, most pregnant women received their influenza vaccine at an obstetrician gynecologist (OBGYN)/midwifery office (36.6%) or another physician office (28.4%); however, a substantial proportion of women (13.2%) received their influenza vaccine at a pharmacy or store.³ Although many OBGYN offices can administer influenza and tetanus, diphtheria, and pertussis (Tdap) vaccines, pharmacists are more easily accessible to help meet this health care need. A routine vaccination, such as influenza, is an important recommendation that pharmacists can provide expecting women to help close gaps in care. Pregnant women are more likely to experience complications from influenza than nonpregnant women,⁴ yet less than 50% of US pregnant women were vaccinated during (or in the months prior to) the 2016-2017 flu season.³ The influenza virus causes more severe outcomes in pregnant women compared with nonpregnant women and can lead to adverse birth outcomes including low birth weight. Additionally, infants younger than 6 months of age have a high burden of complications due to influenza, yet no efficacious influenza vaccines are indicated for this age group. Therefore, the influenza vaccine is recommended for all pregnant women and can be administered during any trimester of pregnancy.⁵

Additionally, vaccination with Tdap during week 27 through week 36 of pregnancy provides fetal and neonatal benefit through passive transport of protective antibodies across the placenta to help prevent pertussis or whooping cough in the neonate.

OPPORTUNITIES FOR PATIENT COUNSELING

Pharmacists can promote preconception health by educating all women of childbearing age on the importance of vaccinations and administering these immunizations when appropriate. Although there have been no adverse reports in pregnant women or their infants after receiving the influenza (flu) vaccine, there has been increasing controversy over the safety of the flu vaccine, and vaccinations in general, especially in children. Pharmacists who administer vaccines can help increase vaccination rates by providing education to patients with proven lower direct cost^6,7 and convenience. Education can include explaining which vaccines are recommended before and during pregnancy, the infections these vaccines can prevent, and the appropriate timing of administration. Discussions should focus on reviewing evidence related to the risks and benefits of vaccinations and dispelling myths about adverse effects. Because some vaccines are not indicated during pregnancy—such as the measles, mumps, rubella and varicella vaccines—pharmacists can help patients plan for administration at least 1 month prior to conception or postpartum. Vaccines for hepatitis A and hepatitis B may be given in some patients, depending on risk factors.¹

Pharmacists can consult the available references to help stay up-to-date on vaccination recommendations, use proven communication strategies to speak with patients on the importance of vaccines, provide patients education materials, and give patients time to discuss their concerns in order to help improve vaccine adherence.² Dispensing prenatal vitamins and other medications specific to pregnancy are additional opportunities for initiating vaccination discussions.

During patient counseling sessions, questions may arise regarding the place in therapy for preservative-free vaccines including concerns regarding thimerosal, a mercury containing preservative found in the multidose vials of the influenza vaccine. Pharmacists can advise patients that there is no scientific evidence that thimerosal-containing vaccines cause health or developmental problems in children born to women who received thimerosal-containing vaccines during pregnancy. Although thimerosal-free formulations are available, the CDC’s Advisory Committee on Immunization Practices does not indicate a preference for their use in any population. Some states have legislation in place regarding the use of preservative vaccines and so it is important for pharmacists to be aware of the legislation in their state of employment. Specific information on states can be found at the Immunization Action Coalition website (Table).

Other inactive ingredients or preservatives found in vaccines include 2-phenoxyethanol, phenol, and bacteria. Adjuvants such as aluminum salts can improve potency and immune response. Other additives such as gelatin, albumin, sucrose, lactose, monosodium glutamate, and glycine have been found to prevent vaccine deterioration and sticking to vial walls. Residuals are remains of the vaccine production process and include formaldehyde, antibiotics (neomycin), egg protein, and yeast protein. For further details on inactive ingredients, pharmacists can refer to the prescribing information or the FDA’s resource (Table).

Pharmacists can also aid in helping pregnant women prepare for travel. The CDC has information on its Traveler’s Health website specific to the destination of travel (Table). Helping patients plan for vaccinations, as well as counseling them on other ways to prevent illness during travel such as washing their hands, avoiding drinking the water in certain geographic areas, and using mosquito repellent to prevent Zika virus, are areas in which a pharmacist may have a positive impact.

CONCLUSION

Pharmacists should advocate for vaccine administration when counseling on preconception, prenatal, and postpartum care, and optimize partnerships with local provider groups to offer bidirectional referrals. In addition to receiving vaccinations themselves, pharmacists should stay abreast of clinical and practice updates regarding vaccinations to best serve their patients.

Brooke L. Griffin, PharmD, BCACP, is a professor of pharmacy practice at Midwestern University Chicago College of Pharmacy in Downers Grove, Illinois.Kathleen M. Vest, PharmD, CDE, BCACP, is a professor of pharmacy practice at Midwestern University Chicago College of Pharmacy in Downers Grove, Illinois.

REFERENCES

• ACOG Committee opinion no. 741: maternal immunization. Obstet Gynecol. 2018;131(6):e214-e217. doi: 10.1097/AOG.0000000000002662.
• Ventola CL. Immunization in the United States: recommendations, barriers, and measures to improve compliance: part 1: childhood vaccinations. PT. 2016;41(7):426-436.
• Ding H, Black CL, Ball S, et al. Influenza vaccination coverage among pregnant women — United States, 2016-17 influenza season. MMWR Morb Mortal Wkly Rep. 2017;66(38):1016-1022. doi:10.15585/mmwr.mm6638a2.
• Omer SB. Maternal immunization. N Engl J Med. 2017;376(13):1256-1267. doi: 10.1056/NEJMra1509044.
• Arnold LD, Luong L, Rebmann T, Chang JJ. Racial disparities in US maternal influenza vaccine uptake: results from analysis of pregnancy risk assessment monitoring system (PRAMS) data, 2012-2015. Vaccine. 2019; 37(18):2520-2526. doi: 10.1016/j.vaccine.2019.02.014.
• Singhal PK, Zhang D. Costs of adult vaccination in medical settings and pharmacies: an observational study. J Manag Care Spec Pharm. 2014;20(9):930-936. doi: 10.18553/jmcp.2014.20.9.930.
• Fontanesi J, Hirsch JD, Lorentz SM, Bowers DA, Shafrin J. Comparison of pharmacists and primary care providers as immunizers. Am J Pharm Benefits. 2009;1(3):150-157.