Drivers and Barriers of Vaccine Acceptance among Pregnant Women in Kenya

In Kenya, tetanus toxoid (TT) is the only maternal vaccine included as part of the Kenya Expanded Programme on Immunization, yet uptake is far below the universal target. Factors such as lower levels of education and lack of knowledge on vaccination during pregnancy have been identified as barriers to maternal vaccination in low- and middle-income countries (LMICs); however, data on maternal vaccine acceptance from African settings are limited. Conducted as part of a larger study examining factors that shape the acceptance of maternal vaccines in Kenya, this analysis assessed drivers and barriers of vaccine acceptance among pregnant women in Kenya.

From October 2017 to January 2018, the researchers enrolled a convenience sample of 604 pregnant women presenting for antenatal care at 7 healthcare facilities in 4 diverse counties (Nairobi, Mombasa, Marsabit, Siaya) of Kenya and from the community in 2 counties (Nairobi, Siaya). The survey instrument was based upon previously used questionnaires and the compendium of survey questions developed by the World Health Organization (WHO) Strategic Advisory Group of Experts working group on vaccine hesitancy.

Overall, 429 (71.0%) reported having received a vaccine in the current pregnancy, and among 433 women with one or more prior pregnancies, 401 (92.6%) reported having previously received a vaccine while pregnant. TT was the most common vaccine received during the current (n = 415, 96.7%) and prior (n = 347, 86.5%) pregnancies. More than 95% agreed that maternal vaccines are "important for my health" and that getting vaccinated is "a good way to protect myself from disease". The most commonly cited reason in favour of maternal vaccination was disease prevention (53.2%), with protection of the baby in the womb as a priority.

Among all participants, 361 (59.8%) had received a recommendation for vaccination during the current pregnancy; healthcare providers (n = 253, 70.1%) were the most frequent source of vaccine recommendation. Other common sources of recommendations for vaccination during pregnancy included relatives (n = 114, 31.6%), friends/neighbours (n = 109, 30.2%), husbands (n = 102, 28.3%), and community health workers (n = 82, 22.7%).

Overall, 36.8% expressed concern about serious adverse effects of vaccines, and 27.0% agreed with the statement that new vaccines carry more risks than older ones. Fear of side effects to mother/baby (15.1%) was the most frequently reported potential barrier. A small proportion of participants (n = 26, 4.3%) reported ever having refused a vaccine for either herself or a child in the past. The most common reasons cited for refusal were not enough information (n = 11, 42.3%) and concerns about safety/side effects (n = 9, 34.6%). Rumours about vaccine safety were mentioned by 3 (11.5%) mothers. Twenty-six (4.3%) mothers reported having a negative experience with a vaccine in the past; 4 (15.4%) women who reported a negative experience also reported ever refusing a vaccine in the past.

When asked about influenza vaccine (not routinely available in Kenya), 402 (66.6%) agreed that a pregnant woman should be vaccinated, and 470 (77.8%) reported that if given the option, they would accept influenza vaccination. However, considering the finding that some participants in this study believe that new vaccines are riskier than old vaccines, the researchers recommend that planning for introduction of new maternal vaccines should take into account perceptions of risk.

Reflecting on the findings, the researchers note that, on the whole, the pregnant women enrolled in this study demonstrated an understanding of the role of vaccine in disease prevention. However, among the small number (n = 26) who had refused a vaccine, lack of sufficient information was the most common reason for refusal provided. Thus, the researchers stress, even in a setting where pregnant women are relatively knowledgeable about vaccines, it is important to ensure that adequate and appropriate information is shared.

Healthcare providers are the main source of vaccine recommendation for pregnant women; thus, the findings suggest that they should be encouraged to consistently advise antenatal patients about vaccination. Of note, relatively few women reported having received a recommendation for vaccination from a community health worker, despite efforts by the Kenyan government to mobilise these personnel to provide outreach and communication on maternal and neonatal health services, including vaccination. The researchers suggest that community health workers represent an underutilised resource for promoting maternal vaccination, particularly in areas with limited numbers of healthcare providers.

In short, the findings demonstrate a willingness on the part of pregnant women in Kenya to accept both currently available and potential future maternal vaccines. Providing adequate vaccine information and addressing safety concerns are identified as strategies for improving maternal vaccine uptake.