Willingness of pregnant women to vaccinate themselves and their newborns with the HPV vaccine

Immunogenicity of 2-Dose HPV Vaccine Series for Postpartum Women: An Open-Label, Nonrandomized, Noninferiority Trial

Importance

Postpartum human papillomavirus (HPV) vaccination is a promising strategy to increase HPV vaccination uptake in the US, particularly for reaching vaccine-naive women and those who lack health insurance beyond the pregnancy period. However, completion of the 3-dose vaccine regimen is challenging.

Objective

To evaluate the immunogenicity of a 2-dose postpartum HPV vaccination regimen (0 and 6 months) and assess whether it is noninferior to a 3-dose postpartum HPV vaccination regimen (0, 1-2, and 6 months) administered to historical controls.

Design, Setting, and Participants

A noninferiority, open-label, nonrandomized immunogenicity trial was conducted from August 4, 2020, to June 23, 2022, of postpartum patients aged 15 to 45 years who delivered at 2 hospitals in Baltimore, Maryland. Historical controls were adolescents and young women aged 16 to 26 years.

Intervention

Two doses of the nonavalent HPV vaccine administered 6 months apart.

Main Outcomes and Measures

The primary outcome was noninferiority (90% CI, lower bound >0.67) of the geometric mean titer (GMT) ratio for HPV-16 among postpartum women compared with historical controls. Secondary outcomes were noninferiority of GMT ratios for the other 8 HPV types and percentage seroconversion for each HPV type. As a noninferiority trial, the primary analysis used the per-protocol analysis.

Results

Of 225 enrolled participants, the mean (SD) age at baseline was 29.9 (6.8) years, and 171 (76.0%) were HPV-16 seronegative at baseline. Of these 171 participants, 129 (75.4%) received a second vaccine dose and completed the subsequent 4-week serologic measurements. Relative to historical controls, the HPV-16 GMT ratio was 2.29 (90% CI, 2.03-2.58). At month 7, HPV-16 GMT was higher after the 2-dose regimen (7213.1 mMU/mL [90% CI, 6245.0-8331.4 mMU/mL]) than among historic controls after the 3-dose regimen (3154.0 mMU/mL [90% CI, 2860.2-3478.0 mMU/mL]). Similarly, the lower bound of the 90% CI of the GMT ratio was above 1 for the 8 HPV types 6, 11, 18, 31, 33, 45, 52, and 58. A total of 118 of 134 women (88.1%) seroconverted for HPV-16 after the first dose; 4 weeks after the second dose, the seroconversion rate was 99% or greater for all HPV types.

Conclusions and Relevance

This study suggests that immunogenicity of a 2-dose HPV vaccination regimen given 6 months apart among postpartum women was noninferior to a 3-dose regimen among young historical controls. Most women seroconverted after the first dose of the 2-dose regimen. These results demonstrate that postpartum vaccination using a reduced schedule may be a promising strategy to increase HPV vaccine series completion.

Trial Registration

ClinicalTrials.gov Identifier: NCT04274153.

Interventions to Improve Knowledge, Attitudes, and Uptake of Recommended Vaccines during Pregnancy and Postpartum: A Scoping Review

Tetanus, pertussis, influenza, and COVID-19 vaccines are recommended for the prevention of related morbidity and mortality during pregnancy and postpartum. Despite the established benefits of vaccination for prenatal and postnatal women, maternal vaccination is not universally included in routine antenatal programs, especially in low- and middle-income countries. Furthermore, the uptake of recommended vaccines among pregnant and postpartum women remains below optimum globally. This review aimed to map the evidence on interventions to improve knowledge, attitudes, and uptake of recommended vaccines among pregnant and postpartum women. We conducted a comprehensive and systematic search for relevant literature in PubMed, Scopus, Web of Science, EBSCOhost, and Google Scholar. Overall, 29 studies published between 2010 and 2023 were included in this review. The majority (n = 27) of these studies were from high-income countries. A total of 14 studies focused on the influenza vaccine, 6 on the Tdap vaccine, 8 on both influenza and Tdap vaccines, and only one study on the COVID-19 vaccine. Patient-centered interventions predominated the evidence base (66%), followed by provider-focused (7%), health system-focused (10%), and multilevel interventions (17%). Overall, the effect of these interventions on knowledge, attitudes, and uptake of maternal vaccines was variable.

Uptake of Human Papillomavirus Vaccine and Intention to Vaccinate among Healthy Pregnant Women in Serbia: A Cross-Sectional Study on Awareness, Knowledge, and Attitudes

We aimed to assess awareness, knowledge, and attitudes of healthy pregnant women towards human papillomavirus (HPV), to estimate factors associated with a positive attitude towards HPV immunization and to assess the uptake of the vaccine among their children. A cross-sectional study was conducted at the University Clinic of Gynecology and Obstetrics, Belgrade, Serbia among pregnant women attending their regular gynecological check-ups at the 12th gestational week. Knowledge about HPV and HPV vaccine was assessed using a specifically designed 12-item and 5-item questionnaires. Out of total 265 included women, 79.3% had heard of HPV, and 37.5% knew that HPV vaccine exists. HPV vaccine knowledge score was associated with higher odds for a positive attitude towards vaccination of both female (OR = 4.10, 95% CI 1.50-11.29) and male (OR = 3.71, 95% CI 1.52-9.01) child. The number of children (OR = 1.32, 95% CI 1.04-1.67) and high vaccine knowledge score (OR = 1.64 95% CI 1.13-2.39) were independent predictors associated with willingness to vaccinate child against HPV. The gynecologist was the preferable point of reference for information seeking about the HPV vaccine. Despite relatively high HPV awareness and knowledge among pregnant women in Serbia, about one-third of them are HPV vaccine aware, and are willing to vaccinate their children against HPV.

Factors associated with hindering the acceptance of HPV vaccination among caregivers - A cross-sectional study in Argentina

Background

The northeastern region of Argentina has the highest age-adjusted cervical cancer mortality rates. Given the strong link between HPV infections and cervical cancer, one of the main interventions is the population-based use of HPV vaccines. However, the acceptability is not very clear in low- and middle-income countries. The purpose of this study was to estimate the level of HPV vaccine acceptance and associated determinants among caregivers of girls in a northeastern city of Argentina.

Methods

A school-based survey was conducted in 2015 using a multistage sampling method. The primary sample unit were schools stratified by socioeconomic status selected at random, and caregivers of school girls were interviewed. The acceptability was determined using the adapted Theory of Planned Behavior. We performed logistic regression models to assess associated determinants.

Results

The study included 347 caregivers. The intention to vaccinate was 59.88%. A positive attitude of caregivers (aOR 4.67; 3.11–7.03) and positive influence of social norms (aOR 1.95; 1.03–3.70) were the main predictors independently associated to the intention to vaccinate against HPV. In contrast, practicing a Christian non-Catholic religion decreased the intention to vaccinate against HPV (OR 0.59; 0.36–0.95). All other factors evaluated were not significantly associated with intention to vaccinate against HPV.

Conclusions

This study shows that evaluating attitudes, normative social beliefs, and perceived self-efficacy regarding HPV vaccination can be of utmost importance for mapping and planning of health-related strategies in developing countries.

Factors affecting the vaccination choices of pregnant women for their children: a systematic review of the literature

In recent years, an increase in vaccine hesitancy has led to a decrease in vaccination coverage in several countries. We conducted a systematic review of studies that assessed knowledge of and attitudes toward pediatric vaccinations, and the vaccination choices and their determinants among pregnant women. A total of 6,277 records were retrieved, and 16 full texts were included in the narrative synthesis. The published literature on the topic shows that, overall, pregnant women believe that vaccines are important for the protection of their children and the community, but various concerns and misunderstandings persist around vaccine safety and efficacy, which reduce the trust of expectant mothers in immunization. Nevertheless, such attitudes and choices vary depending on the vaccine being considered and the corresponding determinants should therefore be studied in the context of each specific vaccination. Further research on this topic is needed, particularly in non-western countries.

A human papillomavirus vaccination program for low-income postpartum women

BACKGROUND

Effective interventions are needed to address the low rate of human papillomavirus (HPV) vaccination in the United States, particularly among girls and women 16-26 years old. Counseling and offering the vaccine to postpartum patients could be an effective strategy to increase uptake among young women who did not complete the 3-dose series at an earlier age.

OBJECTIVE

The purpose of this evaluation was to assess the effectiveness of a multicomponent program designed for postpartum women that used patient navigators (PNs) and reminders for follow-up visits to improve uptake and completion of the HPV vaccine series.

STUDY DESIGN

As part of standard care, patients ≤26 years of age from Galveston County, Texas, who delivered an infant from November 2012 through June 2014 at a public hospital were counseled and offered the HPV vaccine postpartum. PNs assisted with scheduling follow-up injections during postpartum or well-child visits. A program evaluation was conducted after 20 months.

RESULTS

Of 1038 patients approached, only 161 (15.5%) had previously completed the vaccine series. Of the 877 patients who had not completed the series, 661 (75.4%) received at least 1 dose postpartum, with 575 patients receiving their first dose and 86 receiving their second or third doses. By April 2015, initiation rates had increased as a result of this program from 25.4% before the program was initiated to 80.8% and completion rates from 15.5-65.1%. Missed appointments for injections were less likely among those who received text message reminders and more likely among those with ≥2 prior pregnancies. Those who were Hispanic or had received an influenza vaccination in the last year were more likely to initiate and complete the series through this program. Patients who missed ≥1 follow-up appointments were less likely to complete the vaccine series.

CONCLUSION

Offering the HPV vaccine postpartum dramatically increased initiation rates among postpartum patients. PN and text messages ensured that a high percentage completed all 3 doses.