Influenza
Maria G. Tanzi, PharmD
New data published by CDC show that maternal influenza vaccination rates for pregnant women remain low, with only about one-half of women getting the vaccine.1 This is concerning because data suggest that pregnancy increases the risk of influenza-associated hospitalization by more than twofold.
“Changes in the immune, heart, and lung functions during pregnancy make pregnant women more likely to get seriously ill from influenza, and it can even cause premature labor and preterm birth,” said Amy Parker Fiebelkorn, MSN, MPH, CAPT, U.S. Public Health Service, Immunization Services Division, CDC. “While influenza can be very dangerous for pregnant women and their babies, flu vaccination during pregnancy lowers risk of influenza hospitalization in pregnant women by an average of 40%.”
CDC data
Both CDC’s Advisory Committee on Immunization Practices (ACIP) and the American College of Obstetricians and Gynecologists (ACOG) recommend that all women who are pregnant or will be pregnant during influenza season receive an inactivated influenza vaccine. Unfortunately, vaccination rates remain subpar in this patient population.
CDC researchers analyzed influenza data from national surveillance systems to assess disease burden among pregnant women for the 2010–11 through 2017–18 influenza seasons and estimated maternal influenza vaccination coverage rates using internet panel survey data conducted during March and April of 2019. The data showed that from 2010–11 through 2017–18, pregnant women accounted for 24% to 34% of influenza-associated hospitalizations per season in women aged 15 to 44.
The estimated maternal influenza vaccination coverage rates were 53.7% of eligible respondents but were higher in those for whom the provider offered the vaccination or provided a referral for vaccination (i.e., the rate went up to 65.7%).
CDC noted that vaccination coverage rates were lower in black women, unmarried women, those with less education, those who were not working, and those living below the poverty level. Across all patients, two of the most common reasons women said they did not receive the influenza vaccine was the belief that the vaccine was not effective and concerns about safety risks to the infant.
Addressing miscarriage concerns
Some women may have misconceptions about an increased risk of miscarriage when the influenza vaccination is administered in the first trimester. However, according to Fiebelkorn, most studies have not noted an association between influenza vaccination and adverse pregnancy outcomes, including miscarriage.
“One observational study conducted during the 2010–11 and 2011–12 seasons noted an association between receipt of an inactivated influenza vaccine and risk for miscarriage in the 28 days after being vaccinated, [when] the same vaccine had also been received the previous season,” said Fiebelkorn. “However, in a larger follow-up study, inactivated influenza vaccine was not associated with an increased risk for miscarriage during the 2012–13, 2013–14, and 2014–15 seasons, regardless of previous season vaccination.”
The case-control analysis, which was published in October 2019 in Vaccine, assessed whether there was a link between use of the inactivated influenza vaccine in pregnant women and spontaneous abortion.2 Data were obtained from the Vaccine Safety Datalink for the three influenza seasons.
Researchers analyzed data from 627 matched pairs consisting of women who experienced spontaneous abortion and a control group of women who had live births. The pairs were matched on the basis of site, date of last menstrual period, age group, and influenza vaccination status in the previous influenza season. The median gestational age at the time of miscarriage was 7 weeks. Administration of the inactivated influenza vaccine was documented in several risk windows, including 1–28, 29–56, and greater than 56 days before the spontaneous abortion date.
The results showed that there was no association between vaccination in the 1- to 28-day risk window and spontaneous abortion. There was also no association seen for women who were vaccinated in the previous season, in any season, or during any risk window.
Repetition and strong recommendations improve vaccination rates
CDC’s research indicated that some pregnant women did not feel their health care providers strongly recommended vaccines.
Repetition from multiple health care providers can help improve vaccination rates. Pharmacists should provide a strong recommendation to pregnant women on the benefits of receiving the influenza vaccination. When pharmacists are giving the same message that a patient has just heard from her OB/GYN, it reinforces recommendations they are receiving from the OB/GYNs, midwives, nurses, and others.
For many patients, a strong and clear recommendation will be sufficient for them to accept recommended vaccines. Others may need more information. Use the SHARE method in the sidebar on page 18 to address your pregnant patient’s questions and make her feel comfortable about her decision to get vaccinated.
Counseling pearls
Educate patients on the more common adverse effects that may occur with vaccination, such as injection site reactions (e.g., soreness, tenderness, redness, and/or swelling at the injection site). They should also be aware of other adverse effects that may occur, such as headache, muscle aches, fever, nausea, and/or fatigue.
It is also important to educate pregnant women on potential flu symptoms, such as fever, cough, and body aches, and to contact their provider immediately if they experience any of these symptoms. CDC notes that oral oseltamivir is the preferred antiviral treatment for pregnant women because it has the most data in this patient population. The agency also notes that acetaminophen can be used for fever, but patients should always contact their provider and inform them of any potential illness.
Inform patients that millions of women have received the influenza vaccine throughout their pregnancies. Reinforce to women that the vaccine can be given at any time during their pregnancy and can substantially reduce their risk of getting complications from the flu.
Remind patients, in the words of Fiebelkorn, that “flu vaccination not only helps protect the mother and child from serious complications caused by flu during pregnancy, it can protect the baby from the flu for several months after birth when the baby is too young to be vaccinated.”
SHARE method
- Share tailored reasons why the recommended vaccine is right for the patient. For instance, because the patient is pregnant, she is at increased risk of hospitalization if she becomes infected with influenza.
- Highlight positive experiences with vaccines (personal or professional) to reinforce the benefits and strengthen confidence in vaccination.
- Address patient questions and any concerns about the vaccines, including adverse effects, safety, and vaccine effectiveness in plain and understandable language.
- Remind your patient that vaccines can protect her, her baby, and other loved ones from many common and serious diseases, and that getting vaccinated during pregnancy is the best way to protect her baby against influenza and whooping cough (for the Tdap vaccine) in the first few months of life.
- Explain the potential costs of getting the disease, including serious health effects, time lost (such as missing work or family obligations), and financial costs.
Resources for vaccination during pregnancy
CDC has developed a toolkit for prenatal care providers to help increase vaccination rates among pregnant women (www.cdc.gov/vaccines/pregnancy/hcp-toolkit/index.html).
The toolkit has helpful information and resources, including why Tdap and influenza vaccines are important, how to communicate effectively with pregnant women about vaccines, and educational materials to share with staff and patients.
CDC also offers the following information about the safety of influenza and Tdap vaccines during pregnancy:
Other organizations, such as Immunization for Women (https://immunizationforwomen.org/) and ACOG (www.acog.org/), also have resources available on their website for providers and patients.
References
1. Lindley MC, et al. MMWR Morb Mortal Wkly Rep. 2019;68(40):885–92
2. Donahue JG, et al. Vaccine. 2019;37(44): 6673–81