The Maternal Immunization Schedule
If all reproductive-age women had the benefit of preconception healthcare, they might be up to date on recommended vaccines before becoming pregnant. Sadly, this is not the case, and many women—those with low income or lacking health insurance, in particular—are found to be underimmunized when they first present for prenatal care. As a component of this care, obstetric clinicians can address concerns about vaccine safety during pregnancy and ensure that these women receive the vaccines they need.
To aid this process, the American College of Obstetricians and Gynecologists (ACOG) provides an all-in-one resource to help obstetric care providers assess and meet the vaccine needs of pregnant and postpartum women.
"We were getting feedback from our membership that this information needed to be in one place where they could readily find it. That was a driving force behind this committee opinion initiative," said ACOG member Kevin Ault, MD, professor of obstetrics and gynecology at the University of Kansas in Kansas City. Coauthor Laura Riley, MD, associate professor of obstetrics and gynecology, Harvard Medical School, Boston, Massachusetts, seconded the thought, adding that "we wanted something that people could literally tear out, laminate and post on their wall so that everybody has the information at their fingertips." In tabular form, recommendations cover vaccines for every pregnancy, vaccines that can be given to certain women during pregnancy, vaccines that are contraindicated in pregnancy, and vaccines that should be given during the postpartum period.
Maternal Vaccination Status
Obstetricians and gynecologists are in an excellent position to assess a woman's vaccination status and offer the vaccines recommended by ACOG. "Studies consistently demonstrate that when the recommendation and availability of vaccination during pregnancy comes directly from a woman's obstetrician or other obstetric care provider, the odds of vaccine acceptance and receipt are 5-fold to 50-fold higher," committee opinion authors write.
During the initial prenatal visit, providers should ensure that women have immunity against rubella and varicella. This is particularly important for women who, for various reasons, are not aware of their immunization status and in whom the risk for congenital infection affecting the neonate is real.
"A pregnant woman who has not been immunized against measles-mumps-rubella (MMR) or varicella needs to get these vaccines in the postpartum period, even if she is breastfeeding," Riley emphasized. Both the MMR and varicella vaccines are live attenuated vaccines. Although the risk for maternal transmission from a live attenuated vaccine given inadvertently during pregnancy is infinitesimally small, "you don't want to take the chance of a live virus vaccine infecting a pregnant woman and then risk maternal-fetal transmission of the disease," Riley noted: Hence, all live attenuated vaccines are contraindicated during pregnancy.
May Give During Pregnancy
Influenza. Foremost on the list of vaccines that should be given during each pregnancy is the influenza vaccine. Not only can the mother become ill enough require hospitalization, but the infection could increase her risk for preterm delivery. "Her newborn can become incredibly sick as well, and the mortality rate in newborns is high, so the mother can protect not only herself but also her baby if she is appropriately vaccinated," Riley stressed.
Women should receive the influenza vaccine at the same time as everyone else in the fall, Ault pointed out. Ault also tells women with a July or August due date that the upcoming season's influenza vaccine isn't yet available, but it will be given when they return for their first postpartum visit. "The big problem with influenza infection is pneumonia, which is especially problematic in pregnant and postpartum women," he added. Any of the recommended, age-appropriate, inactivated influenza vaccines can be safely given during any trimester.
Tdap. The second vaccine that is recommended during every pregnancy is the Tdap vaccine (tetanus toxoid, reduced diphtheria toxiod, and acellular pertussis). "The Tdap vaccine should be given at 27-36 weeks of gestation in every pregnancy, preferably as close to the 27-36 week window as possible," committee authors point out. As the Society of Obstetricians and Gynaecologists of Canada discuss in a recent press release, pertussis is a transmissible respiratory infection for which infants under the age of 4 months are at greatest risk. The Tdap vaccine is given to pregnant women in an effort to boost the maternal immune response to pertussis and to maximize passive antibody transfer to the newborn, as ACOG explains.
ACOG also notes that women who have never received the Tdap vaccine should receive the vaccine immediately after delivery during the postpartum period, although "vaccination during every pregnancy is preferred over vaccination during the postpartum period to ensure antibody transfer to the newborn," the committee authors state.
Pneumococcal vaccine. The pneumococcal vaccine is not recommended for every pregnancy but it is recommended — and often forgotten — during pregnancy as well as during the postpartum period for high-risk women. High-risk populations include women with heart, lung, or sickle cell disease as well as those with diabetes. "Women who smoke are at high risk for pneumococcal disease and you should be vaccinating them during pregnancy as well," Riley said. The 23-valent pneumococcal polysaccharide vaccine (PPSV23) is recommended for fertile women with a high-risk condition, but the 13-valent pneumococcal vaccine (PCV13) should be used instead in women who are immunocompromised, such as those who are HIV positive. The PCV13 vaccine should also be given only when the benefits of vaccination are believed to outweigh the risks, as committee authors caution.
Vaccines for Special Circumstances
Hepatitis A. As is true for many other regions of the world, the United States has experienced periodic outbreaks of hepatitis A, from which pregnant women can become very ill. Pregnant women with a condition such as chronic liver disease that predisposes them to acquire or have a serious outcome from this infection should be vaccinated against hepatitis A during pregnancy or during the postpartum period.
Meningococcal disease. Outbreaks of meningitis have been reported from time to time in different regions of the country, and pregnant women exposed to any of the Neisseria meningitidis serogroups are at risk for infection. The vaccine against meningococcal serogroup B disease (Bexsero, GlaxoSmithKline), which actually causes the lion's share of meningitis at least in infants and young children, should be deferred in pregnant women unless the woman is at great risk of contracting serogroup B meningococcal disease, according to the committee authors. On the other hand, the quadrivalent meningococcal vaccine against serogroups A, C, W, and Y may be given in pregnancy or in the postpartum setting should any meningococcal disease outbreak place a woman at risk for infection.
Hepatitis B. "It's not unusual in my practice to have a couple in which the husband is hepatitis B surface antigen (HBsAg)-positive and the woman is negative so those are the women you want to vaccinate while you have them in your office," Ault advised. Also at risk for hepatitis B infection are women who live in a household where a household member is HBsAg-positive or who are current or recent injection drug users. If these women wish to be protected against hepatitis B infection, they, too, may receive the hepatitis B vaccine during pregnancy or during the postpartum period.
HPV. Neither of the two vaccines against human papillomavirus (HPV) is recommended during pregnancy. "However, there is no known harm to getting the HPV vaccine while pregnant," Ault said. This was proven conclusively by a study from Denmark in which researchers compared pregnancy outcomes among1665 women who received the quadrivalent HPV vaccine (Gardasil, Merck) during early pregnancy with those from 6660 other women who were not pregnant when they were vaccinated. The findings confirmed that the quadrivalent HPV vaccine did not increase the risk for miscarriage, major birth defects, premature birth, stillbirth, or low birth weight. However, HPV vaccination is still recommended for women up to the age of 26 years and either vaccine can be given in the postpartum setting or to women who are breastfeeding. "What works out very nicely is to give one dose while women are still in the hospital after giving birth and then another dose at the postpartum visit so you have given them 2 of the 3 doses as part of their regular postpartum care," Ault suggested. "And then you can make arrangements for the third dose to be given 4 months after the second dose," he added. Unlike young adolescents who can get away with just two of the three-dose HPV series, older women need the third dose, he added.
Vaccines in development. Other candidate vaccines that can reduce significant infectious disease in neonates are still in the pipeline, but could become important additions to the maternal/newborn vaccine arsenal. One of these is a vaccine against Streptococcus agalactiae, or group B Streptococcus (GBS), which is a major cause of neonatal invasive disease around the world. Since 2014, the World Health Organization has been focusing on the development of a candidate GBS vaccine for use in maternal immunization programs to reduce infections in neonates and young infants worldwide. Another important candidate vaccine that has again been the target of intense research efforts is a vaccine against respiratory syncytial virus (RSV), a leading cause of serious lower respiratory disease in young children.
Prevention of RSV illness in neonates is the desired goal of any RSV vaccine program, as the coauthors agreed. "We are uniquely situated to help out with our female patients so I am hoping that obstetricians-gynecologists will play a role in adult immunization—it is, after all, a public health priority," Ault commented. Riley agreed, adding simply that "we have vaccines that can prevent infections which can be potentially devastating to mothers or their babies."
"And if we just use prevention, we can avoid that morbidity," Riley said.
Medscape Ob/Gyn © 2018 WebMD, LLC
Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.
Cite this: Which Vaccines Do Pregnant Women Need? A New, All-in-One Resource - Medscape - Jul 20, 2018.