As of May 31, 2024, the mother-child immunity vaccine “ABRYSVO® Injection” for the RS virus (Respiratory Syncytial Virus) has been made available across Japan and will be offered at Tokyo Mother’s Clinic starting July 1, 2024.

RS virus (Respiratory Syncytial Virus) is a respiratory infection caused by the RS virus, which is widespread globally, including in Japan. It is one of the leading causes of respiratory infections in infants. More than half of children are infected by the RS virus by the age of one, and nearly 100% of children are infected at least once by the age of two. Symptoms can range from mild cold-like symptoms such as fever and nasal discharge to more severe conditions such as pneumonia. Although about 70% of babies recover within a few days, the other 30%, especially those under six months, are at higher risk of developing severe conditions such as bronchiolitis or pneumonia, which requires careful attention.
There is no specific antiviral treatment for RS virus infection, and treatment is generally symptomatic (e.g., oxygen therapy, IV fluids, respiratory management).

The RS virus spreads through contact and droplets, with infants under the age of one being the most susceptible. Therefore, early prevention from birth is crucial. Since re-infection with the RS virus often causes only mild cold-like symptoms, older children or adults who may unknowingly have the virus could transmit it to infants. Avoiding contact between symptomatic individuals and infants is key to preventing infection.

For the reasons mentioned above, it is crucial to prevent RS virus infection from an early age. The newly approved RS virus vaccine (ABRYSVO®) boosts antibodies in pregnant women, which are then transferred to the fetus through the placenta, providing newborns with protection against RS virus infection. Clinical trials have shown that this vaccine, administered to pregnant women, can reduce the risk of infection by about 50% and the risk of severe illness by about 80% in babies up to six months old. The vaccine is recommended for pregnant women between 24 and 36 weeks of gestation, with the optimal time being between 28 and 36 weeks. However, if the baby is born within 14 days of vaccination, there may not be enough time for sufficient antibodies to transfer to the fetus.

RS virus infection poses a significant health risk for infants, and we highly recommend that expectant mothers consider the RS virus vaccine.

This vaccine is available not only to our clinic’s regular patients but also to expectant mothers who are not registered with our clinic.

For more information, please feel free to ask our clinic staff.