Assessment of the Acceptability of, and Factors Associated With, Recommended Vaccinations During Pregnancy in Maternity Units in the Ile-de-France Region

Certain infections occurring during pregnancy may lead to sometimes severe maternal, obstetric, fetal, and/or neonatal complications. Pregnant women experience higher morbidity and mortality in cases of COVID-19 or influenza infection compared with the general population. Furthermore, pertussis and seasonal influenza are associated with higher morbidity and mortality in newborns and infants than in the general population. In addition, respiratory syncytial virus (RSV) infection-the leading cause of lower respiratory tract infections in newborns and infants-may result in severe bronchiolitis and places a substantial burden on the healthcare system during winter epidemic periods.

Maternal vaccination provides protection for the mother (vaccination against COVID-19 and seasonal influenza) and protects the newborn and infant through the transplacental transfer of specific antibodies (vaccination against pertussis, seasonal influenza, and RSV infection). Vaccines against pertussis, COVID-19, seasonal influenza, and RSV infection are specifically recommended during pregnancy. In France, seasonal influenza vaccination coverage (VC) among pregnant women remains low (30.4%). Pertussis vaccination coverage among pregnant women, estimated using data from the French National Health Data System (SNDS), is 63.2%.

In France, acceptability of vaccination during pregnancy against pertussis, seasonal influenza, COVID-19, and RSV was estimated at 36.1%, 43.9%, 36.8%, and 39.4%, respectively, in a single-center observational study conducted prior to the publication of vaccination recommendations for pertussis and RSV infection. One of the key factors promoting acceptability of these vaccinations is recommendation by healthcare professionals involved in the care of pregnant women. According to data from the 2021 French National Perinatal Survey, the main reason for non-vaccination against seasonal influenza among pregnant women was the absence of a vaccination proposal from a healthcare professional, reported by nearly half of respondents (41.4%).

Improving vaccination coverage among pregnant women and identifying the determinants of such coverage represent a major public health challenge. To date, no study conducted in France has simultaneously assessed vaccination coverage for pertussis, COVID-19, seasonal influenza, and RSV infection in maternity settings. Moreover, no study has yet evaluated the determinants of vaccination against pertussis, COVID-19, and RSV infection among pregnant women following the publication of new vaccination recommendations during pregnancy by the French National Authority for Health (Haute Autorité de Santé).

Primary outcomes

• Survey to Estimate Vaccination Coverage Against Pertussis, COVID-19, Seasonal Influenza, and RSV Infection Among Pregnant Women in Maternity Units in the Île-de-France Region. [Day 0]: Proportion of women vaccinated against pertussis, COVID-19, seasonal influenza, and RSV infection during pregnancy, by department type and by maternity unit type, and then estimate the proportion of vaccinated women across the entire Île-de-France region.

Secondary outcomes

• Survey to determine the proportion of newborns who received RSV immunization through the administration of specific monoclonal antibodies [Day 0]: Proportion of newborns immunized against RSV through administration of specific monoclonal antibodies, born to mothers who were not vaccinated against RSV during pregnancy.
• Survey to assess knowledge of vaccination recommendations for pertussis, COVID-19, RSV, and seasonal influenza during pregnancy [Day 0]: Proportion of women aware of vaccination recommendations against pertussis, COVID-19, seasonal influenza, and RSV during pregnancy, and their sources of information.
• Questionnaire aimed at assessing the proportion of women who are aware of the recommendation for preventive immunization of newborns against RSV as well as identifying their main sources of information. [Day 0]: Proportion of women aware of the recommendation for pre-exposure immunization against RSV through administration of monoclonal antibodies-nirsevimab (Beyfortus®) or palivizumab (Synagis®)-to the newborn, and their sources of information.
• Questionnaire to Identify Factors Associated with Vaccination Against Pertussis, COVID-19, Seasonal Influenza, and RSV During Pregnancy [Day 0]: Vaccination status, knowledge of the listed infections, knowledge of vaccines, vaccination pathway, socio-demographic and socio-economic factors, category of healthcare professional providing pregnancy care.
• Questionnaire to identify factors associated with pre-exposure vaccination against RSV through the administration of monoclonal antibodies to newborns [Day 0]: Factors associated with pre-exposure immunization against RSV through administration of monoclonal antibodies-nirsevimab (Beyfortus®) or palivizumab (Synagis®)-to the newborn.
• Questionnaire to assess the acceptability of vaccination against pertussis, COVID-19, and seasonal influenza in the context of a future pregnancy. [Day 0]: Proportion of women who accepted vaccination against pertussis, COVID-19, and/or seasonal influenza during their pregnancy and who would accept the same vaccination(s) again in a future pregnancy.
• Questionnaire to assess the acceptability of various strategies for preventing RSV and bronchiolitis in newborns in the context of a future pregnancy or birth [Day 0]: Proportion of women whose newborn was immunized against RSV and who would accept either RSV immunization strategy in a future pregnancy/birth
• For women not vaccinated against pertussis during pregnancy, assess: • Reasons for non-vaccination against pertussis. • Acceptability of vaccination against pertussis during pregnancy and postpartum. • Barriers to vaccination against pertussis. [Day 0]: Proportion of women not vaccinated against COVID-19, seasonal influenza, and/or RSV during pregnancy who: i) would have accepted one or more of these vaccinations during that pregnancy, ii) would accept one or more of these vaccinations in a future pregnancy.
• Survey to determine the proportion of women who were not vaccinated against COVID-19, seasonal flu, and/or RSV during their pregnancy and who would have agreed or would agree to receive one or more of these vaccines [Day 0]: Proportion of women not vaccinated against COVID-19, seasonal influenza, and/or RSV during pregnancy who: I) would have accepted one or more of these vaccinations during that pregnancy, II) would accept one or more of these vaccinations in a future pregnancy.
• Questionnaire to assess the acceptability of various strategies for preventing RSV and bronchiolitis in newborns in the context of a future pregnancy or birth [Day 0]: Proportion of women whose newborn was not immunized against RSV who: I) would have accepted either RSV immunization strategy during this pregnancy/birth, II) would accept either RSV immunization strategy in a future pregnancy/birth.
• Questionnaire to assess the reasons for non-vaccination during pregnancy [Day 0]: Reasons for non-vaccination against pertussis, COVID-19, seasonal influenza, and RSV during pregnancy (not offered/refusal/other).
• Survey to describe the vaccination history of pregnant women regarding pertussis, COVID-19, seasonal flu, and RSV [Day 0]: For women vaccinated during pregnancy: * Professional category and practice setting of the healthcare professional who prescribed the vaccination to the pregnant woman (physician, nurse, midwife, pharmacist; maternity unit or community setting). * Professional category and practice setting of the healthcare professional who administered the vaccination to the pregnant woman (physician, nurse, midwife, pharmacist; maternity unit or community setting).
• Survey to determine the vaccination coverage rate for pertussis, seasonal flu, and COVID-19. [Day 0]: Proportion of vaccinating healthcare professionals up to date with their own vaccinations against pertussis, COVID-19, and seasonal influenza.
• Questionnaire to Identify Factors Associated with Pertussis, COVID-19, and Seasonal Flu Vaccinations Administered by Primary Care Providers [Day 0]: Vaccination status, knowledge of the listed infections, knowledge of vaccines, vaccination pathway, socio-demographic and socio-economic factors.
• Questionnaire to assess knowledge of vaccination recommendations for pertussis, COVID-19, seasonal influenza, and RSV during pregnancy. [Day 0]: Proportion of vaccinating healthcare professionals aware of vaccination recommendations against pertussis, COVID-19, seasonal influenza, and RSV during pregnancy, and their sources of information.
• Questionnaire to assess whether healthcare professionals are offering recommended vaccines to pregnant women [Day 0]: Proportion of vaccinating healthcare professionals offering vaccinations against pertussis, COVID-19, seasonal influenza, and RSV to pregnant women.
• Surveys to assess how often healthcare professionals responsible for vaccinations prescribe vaccines during pregnancy. [Day 0]: Frequency with which vaccinating healthcare professionals prescribe vaccinations against pertussis, COVID-19, seasonal influenza, and RSV during pregnancy (never, sometimes, often, always).
• Questionnaire to assess the factors associated with prescribing vaccines "often" or "always" during pregnancy. [Day 0]: Factors associated with "often" or "always" prescribing vaccinations against pertussis, COVID-19, seasonal influenza, and RSV to pregnant women (vaccination status of the healthcare professional for influenza, pertussis, and COVID-19; knowledge of the healthcare professional regarding pertussis; knowledge of the healthcare professional regarding national vaccination recommendations for pregnant women).

Sex: All, ages: 18 Years to any

Inclusion Criteria :

1. Postpartum women:

   * Women aged 18 years and older.
   * Women in the immediate postpartum period (during the maternity stay) having given birth to one or more live-born infants.
   * Women who delivered after 36 weeks of gestation.
2. Healthcare professionals :

   * Vaccinating healthcare professionals (physicians, midwives, or nurses) providing pregnancy care and working in a maternity unit participating in the study.

Exclusion Criteria :

\- Postpartum women :

* Individuals under legal protection (guardianship, curatorship, or trusteeship).
* Women who delivered after fetal death or following a medical termination of pregnancy.

• MARIE LACHATRE, Study chair, Equipe Mobile d'Infectiologie - Hôpital Cochin/APHP