Should Pregnant Women Get the Flu Vaccine?

Is It Safe for Pregnant Women to Get the Flu Vaccine?

This is a common question among expectant mothers who may worry about how the flu vaccine could affect their unborn baby. While seasonal influenza often causes uncomfortable symptoms, it can also lead to serious complications for both mother and baby — including pneumonia, preterm labor, and, in severe cases, increased risk of maternal death.

So, is it safe to get vaccinated against the flu during pregnancy? And if so, when is the best time to do it?

In this article, medical experts from the VNVC Immunization System provide clear, evidence-based answers to help expectant mothers make informed decisions about flu vaccination during pregnancy.

Dr. Đoàn Thị Khánh Châm, Regional Medical Manager (North Region 2) at the VNVC Vaccination System, shared:

“A 2013 study found that flu vaccination during pregnancy can reduce the risk of influenza-associated acute respiratory infection in pregnant women by up to 50%. Another study published in 2018 also showed that pregnant women who received the flu vaccine had a 40% lower risk of being hospitalized due to influenza-related illness.”

She added:

“Vaccinating during pregnancy also offers significant benefits for newborns. It provides passive immunity against the influenza virus during the first few months of life — a period when infants are too young to receive the flu vaccine themselves.”

Should Pregnant Women Get the Flu Vaccine?

Yes — pregnant women are strongly advised to receive the flu vaccine to protect both their own health and that of their baby. According to the U.S. Centers for Disease Control and Prevention (CDC) and other leading health authorities, influenza vaccination is recommended during pregnancy as it significantly lowers the risk of contracting the flu and helps prevent serious complications such as pneumonia, respiratory failure, preterm birth, and miscarriage.

Experts from the VNVC Immunization System explain that pregnant women face a higher risk of flu-related hospitalization compared to non-pregnant women of the same age. Influenza doesn't just affect maternal health — it can also negatively impact fetal development. Several studies have shown that fever, a common symptom of influenza, may be associated with an increased risk of neural tube defects and other complications in newborns.

A 2013 study found that flu vaccination during pregnancy reduced the risk of influenza-associated acute respiratory infections in pregnant women by up to 50%. Another study published in 2018 showed that pregnant women who received the flu vaccine had a 40% lower risk of hospitalization due to influenza-related illness (1).

In addition to protecting the mother, getting vaccinated during pregnancy provides important benefits for the newborn. It offers passive immunity that helps shield the baby from the influenza virus in the first few months of life — a critical period during which the infant is too young to be vaccinated.

Pregnant Women Several studies have indicated that fever — a common symptom of influenza — may be associated with an increased risk of neural tube defects and other complications in newborns.

Timing for Flu Vaccination in Pregnant Women

1. Appropriate Period for Pregnant Women

The flu vaccine can be administered either before pregnancy or at any time during pregnancy, providing practical benefits for both mother and baby. According to guidelines from the WHO, the U.S. CDC, and vaccine manufacturers, pregnant women can receive the flu shot during any stage of pregnancy.

However, current research primarily focuses on the safety and effectiveness of the flu vaccine when given during the second and third trimesters. In the early stages of pregnancy, the fetus is undergoing rapid development, and certain factors may affect the baby's safety. Therefore, if a pregnant woman chooses to get vaccinated during pregnancy, the most suitable time is typically from the second trimester onward, to ensure higher safety and greater peace of mind. (2)

Experts at the VNVC Immunization Center System also recommend that pregnant women get vaccinated as early as possible, as soon as the vaccine becomes available, in order to protect their health throughout the pregnancy and support the baby's immunity after birth.

2. Flu Season

In addition, healthcare professionals advise pregnant women to get vaccinated as early as possible, ideally before or during flu season (typically from around September to April each year). This allows the body enough time to produce antibodies, helping to protect the mother from flu infection and preventing serious complications such as pneumonia, preterm birth, or miscarriage.

"Is it safe for pregnant women to get the flu shot?" is a question many women ask.

Which vaccines are safe for pregnant women?

Currently, two types of quadrivalent flu vaccines are available for pregnant women:

Vaxigrip Tetra Vaccine: This inactivated flu vaccine protects against four common flu strains, including two type A strains (H1N1, H3N2) and two type B strains (Yamagata, Victoria). It was developed by Sanofi Pasteur and produced in France.
Influvac Tetra Vaccine: Another inactivated flu vaccine that protects against four flu strains, including two type A strains (H1N1, H3N2) and two type B strains (Yamagata, Victoria). It is developed by Abbott and produced in the Netherlands.

Both of these vaccines are widely used to help pregnant women protect against the flu, reducing the risk of complications during pregnancy.

When should pregnant women avoid flu vaccination?

While the flu vaccine is recommended for pregnant women, there are certain cases where it may need to be delayed or avoided, including:

Severe allergy to any vaccine components: If a pregnant woman has a history of severe allergic reactions to any component of the flu vaccine, especially severe egg protein allergy, it is important to consult a doctor before getting vaccinated.
High fever or acute illness: If a pregnant woman has a high fever, acute infection, or is seriously ill, vaccination should be postponed until recovery.
Severe reaction to previous flu vaccination: If a woman has had a severe reaction, such as anaphylaxis, difficulty breathing, hives, or other dangerous complications after a previous flu shot, she should not receive another vaccine and should look for alternative prevention methods.
Guillain-Barré Syndrome (GBS): GBS is a rare neurological disorder that may be linked to the flu vaccine. If a pregnant woman has a history of GBS, she should consult with a doctor before deciding to get vaccinated.

In all cases, if there are concerns or questions about flu vaccination during pregnancy, it is advisable to consult with a doctor for appropriate guidance.

Common side effects of flu vaccination in pregnant women?

Pregnant women who receive the flu vaccine, like anyone else, may experience some reactions post-vaccination. However, these reactions are usually mild and resolve within 1-2 days. Common symptoms include pain, swelling, or redness at the injection site, headaches, mild fever, muscle aches, and fatigue.

Safe flu vaccination process for pregnant women

In addition to deciding whether to get the flu vaccine, the process for safe flu vaccination is an important consideration for pregnant women. Flu vaccination is a necessary measure to protect the health of both mother and baby. However, to ensure safety and achieve the best preventive results, pregnant women should pay attention to the following steps before, during, and after the vaccination:

Before the vaccination:

Prepare the vaccination book or certificate for the doctor to check the vaccination history. If unsure about previous vaccinations, discuss with the doctor for proper advice.
Inform the doctor about your health condition, any medications being used, and any allergies (if any) to any vaccine components.
Choose a reputable vaccination facility with experienced doctors and medical staff to ensure safety.
Research the types of flu vaccines available for pregnant women to make the best preparation.
Ensure a healthy diet, adequate rest, and prepare your body to receive the vaccine.

During the vaccination:

Stay calm and cooperate with medical staff to ensure the vaccination process goes smoothly.
Double-check the vaccine information before the injection to ensure it is the correct one.

After the vaccination:

Stay at the vaccination center for at least 30 minutes to monitor any reactions post-vaccination.
Follow the instructions from the medical staff on how to monitor your health at home.
Observe for any abnormal symptoms like difficulty breathing, dizziness, redness, or severe swelling at the injection site. If any unusual symptoms occur, visit a healthcare facility immediately.
Monitor your health during the first 24-48 hours after vaccination.
Drink enough fluids, maintain a proper diet, and get plenty of rest for faster recovery.
If the injection site is swollen or red, apply a cold compress gently to reduce pain and inflammation. Do not apply heat, massage, or use any ointment on the injection site to avoid infection risks.

Pregnant women should stay at the vaccination center for at least 30 minutes to monitor for any reactions after the vaccination.

Frequently Asked Questions

1. Should pregnant women who have had the flu get vaccinated again?

Pregnant women who have had the flu should not get the flu vaccine immediately, as their bodies may not be in the best condition to receive the vaccine. Experts recommend waiting until health stabilizes and the immune system is functioning well to ensure the vaccine's effectiveness.

In addition to pregnant women who are currently sick with the flu, other groups of people should also consider consulting with a doctor before getting the flu vaccine. These include individuals with a history of severe allergic reactions to the flu vaccine, malnourished individuals, those with acute infections, or those allergic to components of the vaccine such as Gentamicin antibiotics or formaldehyde. In particular, people who have previously had Guillain-Barré syndrome—a condition causing progressive paralysis—within 6 weeks after a prior flu vaccination should consult a doctor before deciding to get vaccinated.

2. Should you get the flu vaccine when you first become pregnant?

Getting the flu vaccine as soon as you discover you're pregnant is completely safe and recommended. According to the CDC in the United States, pregnant women are at higher risk for serious complications if they get the flu, including pneumonia, respiratory failure, and even effects on the fetus such as preterm birth, low birth weight, or congenital defects. Therefore, getting the flu vaccine not only protects the mother but also helps create antibodies that are passed to the fetus, providing better immunity for the baby in the early months after birth.

Health organizations like the WHO and CDC confirm that the inactivated flu vaccine (the injectable form) is safe for pregnant women at any stage, including early pregnancy. Therefore, if you discover you’re pregnant during flu season and haven’t been vaccinated yet, it’s advisable to get vaccinated as soon as possible to ensure the health of both the mother and the baby.

The question of whether pregnant women should get the flu vaccine has been addressed in the article above. Pregnant women are at high risk of experiencing severe complications if they contract the flu, which is why getting the flu vaccine is an important measure to protect both the mother's and the baby's health. The vaccine not only reduces the risk of illness and limits dangerous complications like pneumonia, respiratory failure, and preterm birth but also provides passive immunity to the baby after birth.

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