Flu vaccine, RSV vaccine & others are safe before and during pregnancy, protecting mother and child
Conceive NJ encourages our patients to do everything they can to prepare themselves for a safe pregnancy and healthy child. Getting appropriate vaccinations is a fundamental aspect of sound fertility care.
The American Society for Reproductive Medicine (ASRM) advises that vaccinations protect mothers from serious illness and prevent transmission of such illnesses to the fetus. Being vaccinated also passes a mother’s immunity on to her newborn child.
The fall and winter months are particularly active for respiratory viruses, including RSV (respiratory syncytial virus), flu (influenza) and Covid-19.
Get a head start on some vaccines before pregnancy
Being vaccinated before getting pregnant is most effective for many diseases. This applies to vaccines such as MMR (measles, mumps, rubella), Covid-19 and flu vaccines, but not the RSV vaccine (see below).
Each patient should check with their primary care physician on vaccination recommendations, as individual circumstances can dictate the proper time to be vaccinated. ASRM notes that most immunizations should be completed before trying to conceive as some vaccinations can’t be given during pregnancy.
Below, I’ll focus on the flu, RSV and Covid-19 vaccines, as well as others such as whooping cough, measles and Hepatitis B.
Conceive Your Family
Flu shot while pregnant and prior to conception
The flu carries increased risks for pregnant women and their child. Ideally, those trying to conceive or already pregnant should get the flu vaccine at any time during flu season (October-May in New Jersey).
Conceive NJ and the American College of Obstetricians and Gynecologists (ACOG) recommend an inactivated or recombinant flu vaccine (two different manufacturing methods) as soon as they are available. For those who are pregnant, we do not recommend the nasally administered vaccine, which has a weakened live virus in it that can be harmful to the fetus and baby.
Less than half of pregnant mothers get the flu vaccine
In spite of decades of data supporting flu vaccinations in pregnancy, ACOG says that many expectant mothers are not making that choice. In recent years, concerns about the flu shot causing miscarriage, pregnancy complications and autism have grown, leading to hesitancy of some pregnant women in getting the flu vaccine.
Getting the flu vaccine while pregnant or before enables your body to develop antibodies against the disease that you share with your baby. According to the Centers for Disease Control and Prevention (CDC), receiving a flu shot during pregnancy reduces the risk of hospitalization by about 40%.
The flu vaccine also protects babies from the flu and related hospitalizations for the first several months after their birth. Babies are too young to get the vaccine in this time period.
Covid-19 vaccine for those pregnant & trying to conceive
Conceive NJ recommends that individuals receive an updated Covid-19 vaccine or booster before conception, at any stage of pregnancy and postpartum. There has been some confusion about this vaccine for pregnant women coming from the CDC, but as of August 7, 2025, the CDC does recommend Covid-19 vaccination during pregnancy.
Studies consistently confirm that vaccination during pregnancy doesn’t increase risks of miscarriage, birth defects or other adverse outcomes. Data shows that the Covid-19 vaccine is completely safe for use before and during pregnancy.
Passive immunity for the child
A key benefit is passive immunity, meaning antibodies developed by vaccination pass to the fetus, protecting infants during their first months when they are not eligible for the vaccine. ACOG and others note the vaccine significantly reduces serious illness and complications from Covid-19 in pregnant patients and their newborns.
Infants of vaccinated mothers have higher and longer-lasting antibody levels compared with those whose mothers were infected but unvaccinated. ACOG reports that during the 2023-24 respiratory virus season, fewer than 5% of mothers whose infants were hospitalized with Covid-19 had received the vaccine while pregnant.
Fewer ER visits and pregnancy complications
Pregnant women vaccinated against Covid-19 experience fewer emergency room visits and hospitalizations. They also have fewer pregnancy complications such as preterm birth, stillbirth and maternal morbidity.
RSV vaccine for mom; nirsevimab or clesrovimab for baby
Women who are trying to conceive but not yet pregnant should not get the RSV vaccine. Most women of reproductive age are not at risk for severe illness from RSV.
But infants and young children are at risk from RSV. In fact, ACOG notes that RSV is the leading cause of hospitalization for infants in the United States.
RSV vaccine
ACOG recommends that pregnant mothers get the RSV vaccine if:
- They are between 32 and 36 weeks of pregnancy.
- They don’t have a planned birthing within two weeks.
- They did not receive the RSV vaccine in their previous pregnancy.
- They are not going to have their child receive RSV antibody medications.
The RSV vaccine passes antibodies to the fetus and protects the child for 6 months after birth. The only RSV vaccine approved for pregnant women is Abrysvo, made by Pfizer. The vaccine is recommended from September-January when RSV is prevalent.
Nirsevimab or clesrovimab antibodies for the infant, but not the RSV vaccine
Infants can receive an antibody shot of nirsevimab or clesrovimab. These are not vaccines but laboratory-made antibodies that provide protection to the infant or young child.
The vaccine is only recommended during a woman’s first pregnancy, within the guidelines noted above. The RSV vaccine is not needed in the next pregnancy. However, infants in later pregnancies should receive nirsevimab or clesrovimab injections for protection.
Additional information on vaccination during pregnancy
Women trying to conceive or already pregnant should make sure their vaccination information is up to date and discuss each individual vaccine with their primary healthcare provider. Some people are allergic to elements in a vaccine and should not take them. And some vaccines should not be taken during pregnancy.
Conceive NJ recommends the following vaccines during pregnancy for some people
Tdap vaccine for tetanus, diphtheria and pertussis (whooping cough)
One dose each pregnancy. ASRM recommends this vaccination during the early parts of gestational weeks 27-36.
Hepatitis A vaccine & Hepatitis B vaccine
Only those women at high risk for these diseases should be vaccinated. Neither poses a known risk to the fetus.
Pneumococcal vaccine (pneumonia vaccine)
This is recommended for those at high risk for pneumonia. Ideally, women should have the vaccine prior to pregnancy.
Conceive NJ recommends not getting these vaccines during pregnancy
Some vaccines aren’t safe during pregnancy, especially those that are attenuated, meaning they contain a weakened version of a live virus. These can potentially harm a developing baby.
The following vaccines should be avoided during pregnancy but are safe and recommended in certain time frames before pregnancy and afterward.
MMR vaccine
This vaccine for measles, mumps and rubella contains a weakened live virus that can harm a developing child. Pregnancy should be avoided for at least 1 month after the last MMR vaccine dose.
Varicella vaccine (chickenpox vaccine)
In most cases, pregnant women should avoid this vaccine for chickenpox. Women should not try to conceive until 1 month after having the varicella vaccine.
HPV vaccine
The vaccine for human papillomavirus (HPV) is not recommended for pregnant women due to limited data available on safety.
Fast facts on vaccines and pregnancy
Vaccine and pregnancy
Vaccinations protect mothers from serious illness and prevent transmission of such illnesses to their fetus and newborn child. Some vaccines can be taken during pregnancy, while others should be taken beforehand.
Covid vaccine and pregnancy
Covid-19 vaccine is safe before pregnancy and at any stage during pregnancy. Studies show the vaccine does not increase risks of miscarriage or adverse outcomes in a child or mother.
Which vaccines are safe during pregnancy?
These vaccinations are safe to get during pregnancy: flu vaccine, Covid-19 vaccine, RSV vaccine (with limitations), Tdap vaccine, pneumococcal vaccine, Hepatitis A & Hepatitis B vaccines.
Which vaccines are not safe during pregnancy?
These vaccinations are not safe during pregnancy but are recommended after pregnancy and during certain time frames before pregnancy: MMR (measles, mumps, rubella) vaccine, HPV vaccine, varicella (chickenpox) vaccine.
Tdap vaccination during pregnancy and autism
Studies including more than 80,000 children showed that there was no link between the prenatal Tdap vaccine and autism.
In conclusion on vaccinations such as RSV vaccine & pregnancy
Conceive NJ highly encourages women trying to conceive or already pregnant to receive the vaccinations recommended above, per guidelines given. Avoiding diseases is always important, and particularly so when the health of one’s child is involved.
Always check with your primary healthcare provider about your personal use of vaccines and have your vaccination history available at your fertility appointment with Conceive NJ.