RSV vaccine for pregnant women now available at public expense in Ichikawa City.

To Expectant Mothers: A New Vaccine to Protect Your Baby from RSV

Hello. Today, I’d like to talk to you from a pediatrician’s perspective about the newly introduced RSV vaccine. Starting in the 2026 fiscal year , the RSV maternal vaccine will be administered as a routine vaccination for pregnant women.

What is RSV? Why is it scary?

You might have heard the name “RSV” from friends who are raising children. This is a very common virus that causes respiratory symptoms in young children and the elderly. You might be surprised, but it is such a common virus that almost all infants are said to be infected at least once by the time they turn two.

When infected, symptoms such as fever, runny nose, and cough appear, much like a common cold. About 70% of infants infected for the first time experience mild symptoms and naturally recover within a few days. However, we can’t be completely at ease. In the remaining 30% of infants, the cough can worsen, leading to severe illness. Seeing a tiny baby struggling to breathe is truly heartbreaking for families.

The First Gift from Mother to Baby: “Maternal Immunity”

The newly available vaccine is Pfizer’s recombinant RSV vaccine, Abrysvo. The most wonderful thing about this vaccine is that “protecting the baby starts with vaccinating the mother.” When a pregnant woman receives this vaccine, antibodies to fight RSV are produced in her body. These antibodies are firmly transferred to the fetus through the placenta, creating a barrier to protect the newborn baby from RSV right from birth.

Eligible Individuals and Vaccination Schedule

The individuals eligible for this routine (publicly funded) vaccination are as follows:

• Pregnant women between 28 weeks 0 days and 36 weeks 6 days of pregnancy at the time of vaccination.
• Those who have previously received the RSV vaccine (maternal vaccine) during a past pregnancy are also eligible.

During this period, one dose will be administered. The routine vaccination is carried out in the municipality where you are registered as a resident. If you plan to return to your hometown for childbirth and wish to be vaccinated outside your resident municipality, please contact your registered municipality first.

Vaccine Efficacy and Side Effects to Know About

Robust Preventive Effects

This vaccine has been confirmed to have a reliable effect in preventing babies from developing severe pneumonia and other conditions.

• It prevents “severe lower respiratory tract infections (such as pneumonia and bronchitis)” requiring medical attention by about 80% from birth to 90 days of age, and by about 70% up to 180 days of age.
• Even for non-severe lower respiratory tract infections requiring a medical visit, it offers about a 60% preventive effect up to 90 days of age, and about a 50% preventive effect up to 180 days of age.

Regarding Potential Side Effects

You might feel anxious about getting an injection while pregnant, but just like other vaccines, some side effects may occur. The main ones include:

• Pain, swelling, and erythema (redness) at the injection site.
• Headaches and muscle pain.

Additionally, regarding the risk of developing gestational hypertension, clinical trials used for regulatory approval did not show an increased risk of onset. Although some overseas reports have suggested an increased risk, it is noted that these require careful interpretation. If you notice any concerning symptoms after vaccination, please do not hesitate to contact the medical institution where you received the vaccine. Furthermore, if a doctor deems it particularly necessary, it can be administered simultaneously with other vaccines.

Relief System in Case of Emergencies

Vaccinations are very important for preventing infectious diseases, but in extremely rare cases, adverse health effects (becoming ill or being left with a disability) can occur. Because it is difficult to completely eliminate health hazards due to side effects, a relief system is firmly established. This system covers both the individual who received the vaccination and the born child. If you wish to apply for this system, please consult the municipality where your certificate of residence was registered at the time of vaccination.

To protect the precious little life of your unborn baby, please consult closely with your obstetrician/gynecologist and consider getting vaccinated.

For more details, please see the PDF below.