VAC-SIP-YF (Vaccination- Safety & Immunogenicity During Pregnancy- Yellow Fever)

Describe the immunogenicity induced by primary yellow fever vaccination during pregnancy and compare it to the immunogenicity induced by primary vaccination outside pregnancy

Proportion of participants with a neutralizing antibody rate above 1/10. A serological analysis will be performed to measure neutralizing antibody response by using PRNT 80 seroneutralization techniques. Each woman vaccinated against YF during pregnancy will be matched with a woman vaccinated outside pregnancy based on age (+/- 5 years) and time since primary YF vaccination (+/- 6 months). We anticipate that vaccination against YF during pregnancy will be equivalent in term of immunogenicity compared to vaccination against YF realized among non-pregnant women of the same age range. Based on the hypothesis of a protective immune response rate of 90% in the pregnant women group, a sample size in each group of 135, with a normal approximation test of proportions, will allow a type 1 risk of 0.05, a power of 80% and a minimum difference of 5%, in order to reject the null hypothesis according to which the protective immune response rates in the two groups are not equivalent.

Describe the safety of yellow fever vaccination during pregnancy in women who have been vaccinated

The data collected for safety assessment regarding women will include: * Occurrence of YEL-AND or YEL-AVD * Local adverse effects (pain, oedema, erythema, satellite lymph node) * Nausea, vomiting, diarrhea, fever, arthralgia, myalgia * Other adverse events that occurred after vaccination All adverse reactions will be collected following MedDRA guidelines. The proportion of averse events will be compared to that of the non pregnant women group and to that of histoical series.

Describe the tolerability of yellow fever vaccination during pregnancy in the fetus and newborn.

Data collected for safety assessment regarding the fœtus and newborn will include : * Proportion of miscarriage, stillbirth, premature birth, and low weight birth and compare it to that of general population * From the infant health record: * Apgar, weight, size, and cranial perimeter at birth * Birth defect * Physical examination at birth (day 8), 9 month and 24 months of life

Create a biological collection for future studies on infectious/tropical diseases and the immune response to vaccination

This collection could allow : * analysis of cellular response to yellow fever vaccine e.g., activation of dendritic cells, NK cells, B lymphocytes and various T lymphocytes * exploration of participants' cellular immunity and identification of factors influencing the latter * Create a cohort of vaccinated women to assess immunogenicity and safety of all vaccines received during pregnancy