Understanding COVID-19 vaccination decisions during pregnancy and while breastfeeding in a Canadian province

ABSTRACT

Background

Vaccination in pregnancy is important for preventing illness for mothers and babies; however, vaccine uptake in pregnant individuals is lower than non-pregnant females of fertile age. Given the devastating effects of COVID-19 and the increased morbidity and mortality risk for pregnant individuals, it is important to understand the determinants of vaccine hesitancy in pregnancy. The focus of our study was to explore COVID-19 vaccination among pregnant and breastfeeding individuals and its association with their reasons (psychological factors) for vaccination using the 5C scale and other factors.

Methods

An online survey investigating prior vaccinations, level of trust in healthcare providers, demographic information, and the 5C scale was used for, pregnant and breastfeeding individuals in a Canadian province.

Results

Prior vaccinations, higher levels of trust in medical professionals, education, confidence, and collective responsibility predicted increased vaccine uptake pregnant and breastfeeding individuals.

Conclusions

There are specific psychological and socio-demographic determinants that affect COVID-19 vaccine uptake in pregnant populations. Implications of these findings include targeting these determinants when informing and developing intervention and educational programs for both pregnant and breastfeeding individuals, as well as healthcare professionals who are making vaccine recommendations to patients. Study limitations include a small sample and lack of ethnic and socioeconomic diversity.

KEYWORDS:

• 5C model
• COVID-19
• pregnancy
• vaccination
• vaccine decision

1. Introduction

The World Health Organization (WHO) Global Advisory Committee on Vaccine Safety [1] recommends vaccination in pregnancy (VIP) for preventing maternal and neonatal mortality and morbidity. In Canada, the vaccines for influenza and whooping cough (Tdap) are publicly funded and have been universally recommended since 2010 and 2019 respectively [2,3]. However, vaccine uptake in Canadian provinces, such as Alberta, is low as one in five pregnant patients receive the flu-shot and one in four receive the Tdap vaccine [4].

The WHO declared a global pandemic caused by COVID-19 in March of 2020. In December of 2020, vaccines against COVID-19 became available and have been recommended for use during pregnancy and breastfeeding since May 2021 [5]. COVID-19 infection during pregnancy increases the risk of maternal hospitalization, admission to the intensive care unit [6,7], requirement for invasive ventilation [8], preterm birth, low birth weight, admission to the neonatal intensive care unit (NICU) [7,9–11], and may increase risk of a neurodevelopmental diagnosis among infants who were exposed during third trimester infections [12]. Although the impact of the Omicron variant infection during pregnancy appears to be less severe than prior variants, moderate to severe infection continues to be observed in symptomatic pregnant individuals, particularly among those who are unvaccinated [13–16]. However, despite public health recommendations and evidence supporting the safety of COVID-19 vaccination during pregnancy [17,18] or breastfeeding, COVID-19 vaccine uptake has been lower among pregnant people compared to non-pregnant people in Canada. For instance, primary series vaccine coverage among pregnant people was 16% lower than in the general female population of reproductive age in Ontario by the end of 2021 [19].

The reasons behind vaccination in pregnancy decisions, especially during a pandemic, are complex and not fully understood. Vaccine hesitancy is ‘the delay in acceptance or refusal of vaccines despite availability for vaccine services’ [20] and often depends on time, the environment, and the vaccine itself. According to extensive research primarily for influenza vaccination and in Western, Educated, Industrialized, Rich, and Democratic (WEIRD) societies, before the COVID-19 pandemic, provider recommendation and safety concerns were the most decisive factors influencing VIP [21–25]. Provider recommendation for seasonal influenza and pertussis vaccination in pregnancy is associated with ten-times higher odds of being vaccinated (pertussis OR 10.33, 95% CI 5.49–19.43; seasonal influenza OR 12.02, 95% CI 6.80–21.44, and safety concerns deter both seasonal and pandemic influenza (seasonal OR 0.22, 95% CI 0.11–0.44; pandemic OR 0.11, 95% CI 0.06–0.22). Provider recommendation is important among pregnant visible minorities and newly arrived immigrants [26–28]. Prior VIP behavior strongly predicted pandemic (H1N1) vaccine uptake (OR 9.12 95% CI 1.99–41.76), but not seasonal influenza VIP after that (OR 1.51, 95% CI 0.71–3.24) [22]. During the 2009 H1N1 pandemic, pregnant parents’ ‘risk negotiation’ (perceived risk of the illness vs. risk of the vaccine) and provider recommendation increased VIP uptake (OR 6.76, 95% CI 3.1–14.6) [29]. The specific factors that impact VIP within the COVID-19 context are still understudied [30]. Emerging data points to safety fears about vaccine safety, belief that the vaccine is unnecessary, lack of healthcare recommendations, lack of knowledge, and lack of access to the vaccine [31]

To better understand these factors that drive vaccine hesitancy in the general population, Betsch et al. developed the 5C scale [32,33]. As vaccine hesitancy is a prevalent concern and is highly dynamic and complex, the 5C scale was used to investigate how individuals process and make decisions regarding vaccines. The 5C scale is a systematically validated questionnaire that aims to measure psychological antecedents which impact vaccine-related hesitancy and decisions. These psychological antecedents include Confidence (e.g. trust in safety and effectiveness of vaccines), Complacency (e.g. perceived disease risk), Constraints (e.g. structural barriers to access vaccinations), Calculation (e.g. engaging in extensive information seeking about vaccinations), and Collective responsibility (e.g. willingness to protect others, including the unborn baby, through vaccinating). Previously, vaccine hesitancy has been found to be largely impacted by complacency, constraints, and confidence [20], although further investigation on the impacts of the other psychological antecedents is needed [33,34]. For instance, the Calculation construct of the 5C model may be highly relevant within the COVID-19 context as an influx of information regarding the virus and the vaccine was widespread through various platforms, including social media. Previous literature has found that excessive information can disrupt subsequent information processing and thus evoke maladaptive responses, such as anxiety and distress, which can impact decision making [35]. The 5C scale incorporates constructs applied in other widely utilized tools, like the vaccine confidence index [36] to measure vaccine confidence. However, the 5C scale has not been validated for COVID-19 vaccination during pregnancy, and to date, there is no report of using it in the Canadian context.

Understanding the psychological antecedents which impact vaccine-related hesitancy and decisions in pregnancy is crucial to engage in meaningful VIP conversations at the patient-healthcare provider level, for intervention design and implementation, and for policy making and resource allocation. The aim of the present study was to explore pregnant and breastfeeding individuals’ reasons (psychological factors) for self-reported COVID-19 vaccination intention or status in a Canadian province using the 5C scale, and its association with prior vaccination history and demographic characteristics.

Based on previous literature on VIP and vaccine hesitancy according to the 5C’s, we hypothesized that:

1. higher levels of confidence and collective responsibility would be associated with increased uptake COVID-19 vaccine uptake, while increased constraints, complacency, and calculation would be associated with decreased COVID-19 vaccine uptake in pregnant individuals.

2. high level of trust in medical professionals would be positively associated with COVID-19 vaccine uptake.

3. previously receiving a non-COVID-19 vaccine during pregnancy would be positively associated with COVID-19 vaccination uptake.

4. higher level of education and older age would be associated with higher COVID-19 vaccine uptake and residing in rural areas would be associated with lower COVID-19 vaccine uptake in pregnancy.

2. Methods

2.1. Participants and study design

A self-report online survey was conducted via Qualtrics beginning in November 2021, which marked the third wave of the Delta variant in the Canadian province of Alberta, followed by the fourth wave and Omicron variant in December of 2021. Enrollment stopped in March of 2022, once no further participants join the study for several weeks. The sample consisted of pregnant and breastfeeding individuals (n = 237). Participants were recruited primarily through social media platforms. Our patient council helped us share the link to the online survey in pregnancy, breastfeeding and newborn groups across the province. The link was also posted on the University of Calgary research website. Inclusion criteria included individuals who were currently planning a pregnancy, were pregnant, nursing, or a new parent, over the age of 18 years, and currently living in Alberta. Participants provided informed consent prior to beginning the study, and all participation was anonymous and voluntary.

This research was approved by the University of Calgary Conjoint Health Research Ethics Board (REB21–1465).

2.2. Overview of survey

To ensure face validity, survey questions were adapted with input from pregnant and breastfeeding parents to reflect the context for COVID-19 and pregnancy. The online survey included a section regarding demographic characteristics (e.g. age, education level, type of residence, ethnicity, income, etc.). This section was followed by an item on COVID-19 vaccine status and intention (‘What is your current COVID-19 vaccine status;’ ‘Are you planning to be fully vaccinated against COVID-19’), and items regarding prior vaccination history (“Have you been vaccinated against influenza while/outside of being pregnant; ‘Have you been vaccinated against Tdap while being pregnant’). Perceptions of trust in healthcare providers and government to provide COVID-19 advice were assessed using Likert-scales (1 = Not at all to 5 = A lot) [36]. There were no mandatory answer questions. Hence there are questions for which there was missing data.

For the adapted 5C scale, we used Likert scales to assess the extent to which participants agreed with the given statement (e.g. 1 = Strongly disagree to 5 = Strongly agree). The Confidence construct was measured through three items (e.g. ‘COVID-19 vaccines are safe’); Collective Responsibility was measured through two items (e.g. ‘When everyone else is vaccinated, I don’t have to be vaccinated too’); Calculation was measured by two items (e.g. ‘For each and every vaccination, I closely consider whether it is useful for me’); Constraints was measured by one item (e.g. ‘For me, it is inconvenient to be vaccinated against COVID-19’); and Complacency was measured with two items (e.g. ‘Getting vaccinated for COVID-19 is unnecessary because COVID-19 is becoming less common’). We calculated Cronbach’s alpha for each of the psychological antecedents in the adapted 5C scale to determine internal consistency, except Constraints as the adapted scale only had one item.

2.3. Data analysis

All statistical analyses were conducted using IBM SPSS 27.0. Descriptive statistics were conducted to obtain summaries about the demographic characteristics of the sample. To investigate associations between categorical variables, a chi-square test of independence (X2) was used. Additionally, independent samples t-tests were used to test mean differences for the Likert-scale variables between the vaccinated and unvaccinated groups, and between trust in the different levels of government. Because of missing data, the number of participants included in analyses varied from 229 to 237 depending on which questions participants chose to answer.

3. Results

3.1. Participant characteristics

The majority of participants were white (70.9%) and already had at least one child (75.9%). Just under half of the participants were between the ages of 25–34 years old (47.3%); see Table 1.

Table 1. Sample characteristics of pregnant individuals vaccinated or unvaccinated for COVID-19.

	Total Responses (n)	Vaccinated n (%)	Unvaccinated n (%)
Total Sample	237	136 (57.4%)	101 (42.6%)
Currently Nursing and/or New Mother	118	79 (66.9%)	39 (33.1%)
Currently Pregnant	66	38 (57.6%)	28 (42.4%)
Planning or Trying to Become Pregnant	53	19 (35.8%)	34 (64.2%)
Demographics
Ethnicity
Black	1	0 (0.0%)	1 (100%)
East/Southeast Asian	2	2 (100%)	0 (0.0%)
Latino	4	2 (50.0%)	2 (50.0%)
South Asian	2	2 (100%)	0 (0.0%)
Indigenous	3	3 (100%)	0 (0.0%)
White	168	105 (62.5%)	63 (37.5%)
Mixed Race	11	7 (63.6%)	4 (36.4%)
Another race category	3	0 (0.0%)	3 (100%)
Prefer Not Answer/Blank	43	15 (34.9%)	28 (65.1%)
Age Range
18 to 24 years	13	7 (53.8%)	6 (46.2%)
25 to 34 years	112	72 (64.3%)	40 (35.7%)
35 to 44 years	80	43 (0.8%)	37 (46.2%)
45 to 54 years	2	2 (100%)	0 (0.0%)
Prefer Not Answer/Blank	30	12 (40.0%)	18 (60.0%)
Annual Household Income
$30,000 to $49,999	10	7 (70.0%)	3 (30.0%)
$50,000 to $69,999	12	9 (75.0%)	3 (25.0%)
$70,000 to $89,999	29	15 (51.7%)	14 (48.3%)
$90,000 to $109,999	36	22 (61.1%)	14 (38.9%)
Over $110,000	98	64 (65.3%)	34 (34.7%)
Under $29,999	2	0 (0.0%)	2 (100%)
Prefer Not Answer/Blank	50	19 (38.0%)	31 (62.0%)
Area of Residence
Rural	49	25 (51.0%)	24 (49.0%)
Urban/Suburban	151	98 (64.9%)	53 (35.1%)
Prefer Not Answer/Blank	37	13 (35.1%)	24 (64.9%)
Number of People in Household
1 person	4	3 (75.0%)	1 (25.0%)
2 people	32	21 (65.6%)	11 (34.4%)
3 people	75	51 (68.0%)	24 (32.0%)
4 people	55	33 (60.0%)	22 (40.0%)
5 people	30	12 (40.0%)	18 (60.0%)
6 or more	8	2 (25.0%)	6 (75.0%)
Prefer Not Answer/Blank	33	14 (42.4%)	19 (57.6%)
Have Children
No	40	29 (72.5%)	11 (27.5%)
Yes	180	100 (55.6%)	80 (44.4%)
Prefer Not Answer/Blank	17	7 (41.2%)	10 (58.8%)

3.2. The 5C constructs and COVID-19 vaccine in pregnancy uptake

The adapted 5C scale constructs’ Confidence, Complacency, Collective Responsibility and Calculation Cronbach alpha were 0.965, 0.798, 0.697, and 0.537 respectively; the adapted scale only had one item to explore Constraints (See Table 2). In our adapted scale, Confidence, Complacency and Collective Responsibility had adequate reliability to measure the reason for vaccination behavior (psychological antecedent) that they were intended to assess. Reliability for Calculation was low and the reliability for Constraints was not known.

Table 2. Cronbach’s alpha for 5C scale survey questions.

5C Scale	Survey Questions	Cronbach’s Alpha (α)
Confidence	COVID-19 vaccines are safe	0.965
	COVID-19 vaccines are safe for pregnant and/or nursing individuals
	COVID-19 vaccines are effective in preventing COVID-19 infection
Complacency	Getting vaccinated for COVID-19 is unnecessary because COVID-19 is becoming less common in pregnancy	0.798
	COVID-19 is not severe enough to vaccinate against in pregnancy
Collective Responsibility	When everyone else is vaccinated for COVID-19, I don’t have to be vaccinated too	0.697
	Vaccination is a collective action to prevent the spread of COVID-19
Calculation	For each and every vaccination, I closely consider whether it is useful for me	0.537
	When I think about being vaccinated, I weigh the benefits and risks to make the best decision possible
Constraints	For me, it is inconvenient to be vaccinated for COVID-19	N/A

Independent samples t-tests were conducted to investigate how COVID-19 vaccine uptake in pregnant individuals was related to scores on the 5C scale. There was a large and statistically significant difference in Confidence reported (t(219.30) = −27.34, p < .001, d = 3.53) between those who were COVID-19 vaccinated (M = 4.27, SD = .91), and those who were not (M = 1.36, SD = .67). Likewise, vaccinated individuals reported much lower Complacency (t(155.39) = 13.79, p < 0.001, d = 1.99) than unvaccinated individuals. Collective Responsibility differed significantly (t(154. 36) = −16.97, p < 0.001, d = 2,44) between the unvaccinated (M = 2.41, SD = 1.10), and the vaccinated participants (M = 4.65, SD = .77). There were also significant differences on Calculation and Constraints between vaccinated and unvaccinated participants (t(222) = 3.89, p < 0.001, d = .53) and (t(126.57) = 5.94, p < 0.001, d = .90), respectively.

3.3. Prior non-COVID-19 vaccination status and COVID-19 vaccine in pregnancy uptake

A chi-square test of independence was conducted to examine if there was a relationship between previously receiving a non-COVID-19 vaccine during pregnancy and outside of pregnancy, and COVID-19 vaccination uptake. Participants who previously received a non-COVID-19 vaccine during pregnancy and outside of pregnancy were more likely to report COVID-19 vaccination, (X2(1, N = 229) = 67.63, p < 0.001) and (X2(1, N = 229) = 21.55, p < 0.001), respectively. Those who reported that they received a Tdap vaccine during pregnancy were also more likely to be vaccinated against COVID-19 than those who did not receive a Tdap vaccine (X2 (1, N = 229) = 41.07, p < 0.001). The same pattern was observed for individuals who reported previously receiving the influenza vaccine (X2 (1, N = 229) = 83.42, p < 0.001).

3.4. Trust in healthcare providers and the COVID-19 vaccine uptake

An independent samples t-test showed that the COVID-19 vaccine uptake group had significantly higher level of trust in healthcare providers (M = 4.44, SD = .80) compared to those who were not vaccinated (M = 2.41, SD = 1.09), t(156.50) = −15.22, p < 0.001, d = 2.53.

3.5. Trust in different levels of government regarding COVID-19 medical and health advice

Participants reported a higher level of trust in the local (municipal) government compared to the provincial government ((M = 2.24, SD = 1.28 Vs M = 1.60, SD = .93), t(219) = −9.08, p < 0.001, d = 0.61) and higher level of trust in the federal government compared to the provincial government ((M = 2.19, SD = 1.30) Vs (M = 1.60, SD = .93) t(219) = −8.00, p < 0.001, d = 0.54)).

3.6. Associations between education, age, residence area, and COVID-19 vaccine uptake

There was a small but significant association between reporting higher education and being vaccinated against COVID-19 (r = .30, p < 0.001). A subsequent chi-square analysis confirmed that education level and COVID-19 vaccine uptake were associated (X2(6) = 28.44, p < 0.001). There was no association between age and COVID-19 vaccine uptake, when analyzing age as a categorical variable – as it was collected- (X2(3) = 3.69, p = 0.30) and only a small but positive correlation (Pearson correlation coefficient r = .13, p = 0.04) after converting categorical age intervals to numeric ages (e.g. 18–24 years = 18 years). There was no significant association between COVID-19 vaccination status and place of residence (X2(1) = 3.01, p = 0.08).

For full summary of results see Table 3.

Table 3. Summary of Results.

	Vaccinated	Unvaccinated
5C Constructs	Mean (SD)	Mean (SD)		t-value, p-value	Cohen’s d (95% CI)
5C Constructs: Independent Sample t-test results
Confidence	4.27 (0.91)	1.36 (0.67)		25.89, < .001)	3.53 (3.11, 3.96)
Complacency	1.35 (0.82)	3.26 (1.12)		14.51, <.001,	1.99 (1.66, 2.32)
Collective Responsibility	4.65 (0.77)	2.41 (1.10)		17.98, < .001	2.44 (2.09, 2.79)
Calculation	3.76 (1.02)	4.30 (1.03)		3.89, < .001	0.53 (0.26, 0.80)
Constraints	1.33 (0.94)	2.580 (1.70)		6.54, <.001,	0.90 (0.62, 1.18)
Trust in Healthcare Providers: Independent Sample t-test results
	4.44 (0.80)	2.41 (1.09)		p < .001,	d = 2.53
	Mean (SD)		t-value, p-value (Comparison to provincial government)		Cohen’s d (95% CI)
Trust in Different levels of Government: Independent Sample t-test results
Local (municipal)	2.24 (1.28)		9.08, < 0.001		0.61 (0.47–0.76)
Provincial (Alberta)	1.60 (0.93)
Federal (Canada)	2.19 (1.30)		8.00, < 0.001		0.54 (0.40, 0.68)
Vaccine Determinant	X^2 Test of Independence			Interpretation
Vaccine History: Chi-square test of independence
Non-COVID-19 vaccine during pregnancy	X^2(1, N = 229) = 67.63, p < .001			more likely to report COVID-19 vaccination
Non-COVID-19 vaccine outside of pregnancy	X^2(1, N = 229) = 21.55, p <.001			more likely to report COVID-19 vaccination
Tdap during previous pregnancy	X^2 (1, N = 229) = 41.07, p < .001			more likely to report COVID-19 vaccination
Influenza vaccine during previous pregnancy	X^2 (1, N = 229) = 83.42, p < .001			more likely to report COVID-19 vaccination
Demographic	X^2 Test of Independence			Interpretation
Demographics: Chi-square test of independence
Education Level	X^2(6) = 28.44, p <.001			Higher education associated with being vaccinated
Age	X^2(3) = 3.69, p = .30			Not significant
Place of Residence	X^2(1) = 3.01, p = .08			Not significant

4. Discussion

This study is the first to investigate the association between COVID-19 vaccination status in pregnancy and its association with psychological factors (using the 5C scale) that are related to whether or not a person gets vaccinated. We found that COVID-19 vaccination during pregnancy was strongly associated with the psychological antecedents of Confidence, Complacency, and Collective Responsibility, a history of having received a non-COVID-19 vaccination during pregnancy, as well as trust in their healthcare providers.

An important and novel objective of our study was to apply the 5C scale as a determinant of COVID-19 vaccine decisions in pregnancy. All of our hypotheses regarding adapting the 5C scale to a pregnancy context were confirmed in the present study, providing new and important insight into how pregnant individuals think and feel about COVID-19 vaccination and being vaccinated. Participants who reported being COVID-19 vaccinated believed that the COVID-19 vaccine is safe and effective, which is consistent with findings for other non-COVID-19 VIP studies. Unvaccinated individuals were less likely to perceive COVID-19 infection in pregnancy as threatening to them (Complacency), which is consistent with previous literature investigating the role of this factor in vaccine acceptance [33]. However, this finding needs further exploration because pregnant individuals who feel very concerned about contracting a severe disease (e.g. COVID-19) and are also very worried about vaccine safety can experience intense decisional conflict and, as a result, not get vaccinated [37]. This phenomenon has been reported in qualitative VIP studies [37]: ‘…fear if I do (vaccinate), fear if I don’t (vaccinate), and do nothing when I fear both,’ and with childhood vaccinations [38]. COVID-19 vaccinated participants cared more about protecting others (Collective responsibility), in keeping with findings in the general population as those who exhibit higher Collective responsibility have a higher sense of collectivism and empathy [30]. Even though the reliability of the adapted 5C scale for Calculation was lower than for the prior three factors, participants who were not COVID-19 vaccinated were more likely to engage in more information seeking. These findings are supported by psychological principles such as Cognitive Load Theory [35,39], wherein ‘information overload’ often has negative outcomes as it results in individuals feeling fatigued, overwhelmed, and anxious, all of which can impact their decision-making processes.

In our study, COVID-19 vaccinated participants were more likely to report having received another vaccine during their pregnancy (e.g. Tdap or flu), consistent with our hypotheses. This is an important finding because prior VIP behavior strongly predicted pandemic (H1N1) vaccine uptake (OR 9.12 95% CI 1.99–41.76), but not seasonal influenza VIP after that to the same extent (OR 1.51, 95% CI 0.71–3.24) in the largest systematic review in the topic published to date [22]. COVID-19 vaccinated participants were more likely to have received the influenza rather than the Tdap vaccine. Both influenza and COVID-19 infections during pregnancy can lead to serious adverse events like maternal respiratory failure and preterm birth, so it is possible that the desire to prevent those complications drives the association between COVID-19 and influenza vaccinations status.

Consistent with our hypotheses, and prior literature for other vaccines in pregnancy, we found that COVID-19 vaccinated individuals reported higher trust in their nurses, doctors, and/or midwives. Previous studies have revealed that pregnant patients were more likely to receive influenza and Tdap vaccines when recommended to do so, and the primary reason for not vaccinating was due to a lack of healthcare recommendations [40,41]. This information is pertinent to developing interventions to improve HCPs vaccine communication skills, especially since healthcare have reported workers feeling anxious or ill-equipped to deliver accurate information and vaccine recommendations to their patients [42]. Our data confirmed our hypothesis that COVID-19 vaccination status would be associated with higher education attainment, in keeping with prior literature [35,43–45], although some studies have found the opposite effect [33] We did not find an association between COVID-19 vaccination and participants’ age. Younger age was previously found to be a determinant of vaccine hesitancy in both non-COVID-19 and COVID-19 studies [46]. We initially hypothesized that younger pregnant individuals would be less likely to be vaccinated against COVID-19 because of their social media consumption and their perception of health [26,47]. However, it is important to note that in our study, we did not have many participants in the upper age range (45–54 years), where previous literature found the largest differences in vaccine hesitancy [28,48].

The findings of the present study are based on a Canadian sample. Similar outcomes to the present study have been documented in other literature. Higher levels of education and income, employment status and previous influenza vaccination predicted decreased vaccine hesitancy in Canada and the United States [49,50]. Conflicting results have also been documented in the literature; for instance, higher education and income was found to be associated with increased hesitancy in Turkey [51], which is in contrast to the findings in our study and in other nations, such as France and Japan [52,53]. Lastly, other factors and determinants have been identified in the literature across several countries, such as a history/presence of chronic disease, full-time work status, and essential worker status [50,51]. It is important to acknowledge the various determinants of vaccine hesitancy in a cross-cultural context, in order to tailor and implement effective intervention and guide clinical practice in different countries.

Vaccine hesitancy has been identified as one of the top threats to global health [54], and there is a need to develop metrics that not only can quantify vaccine hesitancy, and that also can provide insights on the reasons related to vaccination behavior. We focused on improving our understanding of pregnant individuals’ reasons related to vaccination behavior because pregnant individuals and their babies can be severely and disproportionally affected by vaccine preventable infectious disease outbreaks and pandemics, including now COVID-19. Our study provides a preliminary, foundational step toward enhancing our understanding of vaccine hesitancy for expecting and new mothers, using psychological factors that impact cognitive processes and behavior. Expanding this knowledge is important as it has clinical and practical implications at the individual, community, and policy-making levels. Findings from this research can inform healthcare policy (i.e. developing and implementing effective interventions for healthcare workers to recommend the COVID-19 vaccine during pregnancy), and government policy to increase vaccine accessibility and availability for pregnant individuals.

It is important to interpret the results of our study within the context of its limitations, including a relatively small sample size and the lack of demographic diversity, including limited representation from diverse ethnic origins and socioeconomic status (i.e. most of our participants were predominantly white, high-income, and living in urban areas). Previous literature has found that racialized minority groups exhibit higher levels of vaccine hesitancy [55]. It should be noted that our study did not collect information on participants’ birth region or immigrant status, which may have influenced their vaccination status. Örtqvist and colleagues (2022) found that among pregnant women from Sweden and Norway, those born outside of Scandinavia had lower vaccine uptake [56]. Lastly, other studies have included additional participant characteristics that may refine our understanding of vaccine decision-making among pregnant individuals, like medical conditions (obesity, pre-gestational and/or gestational diabetes) and miscarriage history [18].

In addition, future studies should aim to better understand differences in vaccine uptake between pregnant and postpartum individuals who are breastfeeding in Canada. Previous research has yielded mixed findings: while one study in Germany found that vaccine uptake among breastfeeding individuals was higher than that of their pregnant counterparts [57], a review paper found no significant differences between these two groups [31]. Given the importance of the 5C context in shaping vaccination decision-making among these populations, gaining a deeper understanding of the factors that influence their choices will be essential for the development of effective interventions to increase vaccine uptake.

5. Conclusion

There are individual differences that impact vaccine uptake in pregnant populations. It is important to consider specific determinants when informing and developing intervention and educational programs for both pregnant and breastfeeding mothers as well as healthcare professionals to influence vaccination in pregnancy uptake.

Abbreviations

WHO	=	World Health Organization
VIP	=	Vaccination in Pregnancy
WEIRD	=	Western, Educated, Industrialized, Rich, and Democratic
NICU	=	Neonatal Intensive Care Unit

Declaration of interest

E Castillo received an honorarium for speaking at educational events from Sanofi June 2021, Sanofi September 2021, and Pfizer in June 2022. She has spoken at educational events sponsored by Moderna in October 2022 and Pfizer in December 2022 without receiving any compensation. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or material discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

All authors have substantially contributed to this article and have been involved in writing and revising it. Conceptualization EC and MB; methodology EC; analysis GB and GG; resources EC; data curation MB; writing – original draft preparation MB, KL and EC; writing – review and editing EC, GG, MB, MS, KL and GB; visualization KL, MB, and GB; supervision EC; project administration MB; funding acquisition EC. All authors have read and agreed to the published version of the manuscript.

Previous Presentations

Preliminary results from this study were presented in a poster at the Infectious Diseases Society for Obstetrics and Gynecology (IDSOG) 2022 Annual Meeting in Boston, MA on August 4–6, 2022, and as an oral presentation at the Canadian Immunization Conference (CIC) 2023 in Ottawa, Ontario on 25 April 2023

Acknowledgments

The authors would like to acknowledge the Protecting Every Mom & Baby Alberta Parent Partner Research Advisory Committee (PEMBA PPRAC) for their contributions to the conceptualization of the survey, input into the survey design and assistance with distributing the survey to parents in Alberta.

Data availability statement

Data from this study is available upon request.

Additional information

Funding

Funding for this study was provided by the Public Health Agency of Canada (PHAC) [2122-HQ-000436]. The views expressed herein do not necessarily represent the views of PHAC