Pregnancy and vaccines: what vaccines? -when? Health Magazine

Are you pregnant or do you plan to be soon? This may be the time to take stock with your doctor and update your vaccination schedule. All the answers to your questions with Dr. Philippe Poujol from the Institut Pasteur Medical Center.

Are you immune to rubella? Measles ? When was your last tetanus recall? If the vaccination schedule is rather well respected in childhood and adolescence, it is clear that in adulthood, we lose sight of it a little! However, vaccination allows you to protect yourself and those around you. "In the case of pregnancy, you should know that the vaccine will protect both the pregnant woman and the unborn child from potentially serious diseases such as whooping cough, chicken pox, influenza, rubella or even measles" warns Dr. Poujol.

Reminder: the basics of the vaccine

There are two types of vaccines:

Live attenuated vaccines are made from live germs (viruses/bacteria) that have been modified to lose their infectivity. With some exceptions, they are contraindicated during pregnancy due to the possibility of the virus crossing the placenta and contaminating the baby.

Inactivated vaccines do not contain live infectious agents and can therefore be used without any problem during pregnancy.

Get vaccinated before pregnancy

Are you planning to get pregnant soon? This is a good time to go and discuss your vaccinations with your doctor. “From the moment you decide to embark on a pregnancy, you have to anticipate, confirms Dr. Poujol. Indeed, some so-called live virus vaccines such as MMR (Measles-Mumps-Rubella) or that against chickenpox are contraindicated during pregnancy. It is therefore recommended to do them at least a month before becoming pregnant.

Vaccination against rubella

As a reminder, although rubella is not dangerous for pregnant women, it can cause serious malformations in the fetus. The risk of transmission from mother to child of this viral pathology is around 80% during the first trimester. In the event of affection by the rubella virus before the twelfth week of amenorrhea, in addition to the risk of death of the baby, there is a very high probability of malformations of the eyes (risk of blindness), hearing (risk of deafness), but also cardiac and neurological (brain damage with possible mental retardation).

In 50% of pregnant women, rubella is asymptomatic, that is to say, it does not give any symptoms. The second half may present with a rash - sometimes mistaken for an allergy - accompanied by a little fever or even conjunctivitis. "In the absence of immunization against rubella, the pregnant woman cannot be vaccinated during pregnancy, she must imperatively avoid any contact with a person likely to be contaminated during the first four months of pregnancy" specifies the doctor. . In order to protect possible other pregnancies, the rubella vaccine can be carried out after childbirth. This does not prevent breastfeeding.

Vaccination against measles

Considered to be a benign viral disease of early childhood, measles can be serious when it occurs in pregnant women with an increased risk of miscarriage or premature birth. “Unlike chickenpox or rubella, measles does not cause malformations in the fetus,” says Dr. Poujol. On the other hand, it can have very serious consequences and be complicated by measles pneumonia or even encephalitis, that is to say an inflammation of the brain tissue which can cause serious sequelae. On the other hand, if the baby is born when the mother has measles, the virus can cause neurological complications in the infant. A pathology not to be taken lightly!

Vaccination in pregnant women is not recommended, if you are not immunized, it is essential to avoid any risk of contagion. Especially since measles is on the rise in France with a very active circulation of the virus in certain regions since 2017. “From the beginning of 2018 to the end of 2019, nearly 6,000 cases of measles were reported in France, with epidemic in several regions, specifies Public Health France in a report published in 2020. The completeness of the mandatory declarations being 50%, double the number of cases must have occurred. Nearly 90% of those affected were not or poorly vaccinated. For the record, complete vaccination against measles requires two injections at least one month apart.

Finally, a mother vaccinated against measles transmits antibodies to her child. “Vaccination against measles is not indicated before twelve months in the baby, the infant already benefits from protection. It's far from negligible."

Vaccination against chickenpox

A benign disease of early childhood, chickenpox is rare but potentially serious when it occurs in pregnant women. The virus contracted between the eighth and twentieth week of amenorrhea exposes the fetus to the risk of neurological malformations and the mother to respiratory problems. Neonatal chickenpox, on the other hand, can seriously endanger the life of the infant. So, if in doubt, before embarking on a pregnancy project, ask your doctor for advice, who can prescribe a serology (a simple blood test) to check that you are well immunized against the virus. Otherwise, do not hesitate to get vaccinated!

Vaccination in pregnant women

During pregnancy, many infections can jeopardize the health of the mother or increase the risk of miscarriage or premature delivery . “So you might as well prevent them from happening,” emphasizes Dr. Poujol. Vaccines against typhoid, hepatitis A and B, meningococci (A, C, Y, W135) can therefore be recommended when traveling to an endemic zone”. As the saying goes, prevention is better than cure...

Vaccines against hepatitis A and B

Vaccines against hepatitis A and B are inactivated virus vaccines and can therefore be administered during pregnancy on the advice of your doctor. "They are indicated especially when traveling to a region of the world where there is a risk," says the doctor. For example, if a pregnant woman has to stay ten days in Morocco, it is good that she is vaccinated against hepatitis A”. Hepatitis A is a major public health problem in the Middle East and North Africa. Contamination occurs by ingesting contaminated water or food through direct contact with an infected person. However, the occurrence of hepatitis A in pregnant women can lead to a risk of premature delivery and gestational complications.

The hepatitis B vaccine is recommended when there is a significant risk of being contaminated by the virus: contact with an infected person, drug addiction, etc.

Typhoid vaccine

Seventeen million people worldwide are affected by typhoid fever each year. The bacterium of the salmonella family is also transmitted there by ingestion of water or food contaminated with feces. Depending on the length and conditions of the stay, vaccination is strongly recommended for pregnant women who plan to travel to risk areas: in particular India and South-East Asia. The typhoid fever vaccine is an inactivated vaccine made up of antigenic fragments of the bacteria. A single injection, fifteen days before departure, is enough to protect you for three years.

Yellow fever vaccine

While live attenuated yellow fever vaccine is generally contraindicated during pregnancy, a doctor may recommend it if you must travel imperatively in risk areas. “A pregnant woman who has to go to Guyana or sub-Saharan Africa and who cannot delay her stay for one reason or another should consider getting vaccinated against yellow fever, warns Dr. Poujol. There is currently no treatment and since the disease is potentially serious, the benefit/risk balance leans in favor of vaccination”.

The vaccine against Covid-19

Even if there are currently very few studies of the impact of the vaccine against Covid-19 in pregnant women, the French authorities now recommend getting vaccinated from the first trimester of pregnancy. “In pregnant women, the respiratory capacity being reduced, in particular during the last trimester, an infection with the Covid-19 virus exposes to the risk of serious forms and complications, recalls Dr. Poujol. pregnant women who already have risk factors: high BMI, diabetes, etc. The benefit/risk balance leans very favorably for vaccination”.

To date, both messenger RNA vaccines (Pfizer and Moderna) are recommended. As messenger RNA vaccines are devoid of infectivity, there is no reason to fear infection of the fetus by SARS-Cov 2 during vaccination during pregnancy.

Flu and pregnancy

As seasonal flu can be potentially serious in pregnant women, it is recommended to get vaccinated during pregnancy. "The disease can have very significant repercussions in the last trimester because the mother's respiratory capacity is reduced and her immune system is less efficient and therefore more fragile" warns the specialist. Since influenza vaccines are inactivated virus vaccines, that is to say without infectivity, there is no reason to fear an embryo-fetal infection during vaccination during pregnancy and they do not prevent not breastfeeding. In addition, according to the CRAT: "After maternal vaccination in the second part of pregnancy, the transplacental passage of influenza-specific antibodies provides protective antibody levels in children for at least their first 2 months of life".

What vaccines after pregnancy?

Vaccination against pertussis

Finally, pertussis is transmissible from mother to newborn and potentially serious in children less than 12 months, the vaccine is strongly recommended before pregnancy or immediately postpartum.

Vaccine and breastfeeding

According to the Leche League, none of the commonly administered vaccines are contraindicated during breastfeeding. Even the one against Covid-19. Two studies recently carried out by Spanish researchers have even shown that the breast milk of vaccinated women contains antibodies against SARS-Cov 2.

National Institute for Health Surveillance (INVS)

Infectiology.com

Public Health France

www.lecrat.fr

La Leche League