Can I get the rabies vaccine if I'm pregnant?

Recently, the International Journal of Community Medicine and Public Health published a case report of post-exposure treatment (PEP) for rabies after a pregnant woman was bitten by a pet dog. At the same time, the author also combined the existing evidence to give a brief review of the safety of rabies vaccine injection in pregnant women.

Because rabies is a fatal disease, the vaccine instructions stipulate that rabies vaccine after exposure has no contraindications. WHO also clearly states that rabies vaccine and RIG can be used safely in pregnant and lactating women. However, in reality, pregnant women still have tension and anxiety, and worry that vaccination will bring a series of safety problems. This issue will review the relevant literature on previous vaccination of pregnant women with Vero cell rabies vaccine to explore the safety of PEP.

Review of safety studies of Vero cell rabies vaccine in pregnant women

There are a total of 444 pregnant women in the listed literature, aged between 18 and 40 years old. Most of the Class III exposed patients were injected with passive immune preparations in addition to vaccination, while 39 Class III exposed patients in Guangzhou, China refused to be injected with passive immune preparations. First, they believed that the risk of infection in contact with pets was low and there was no need for injection. Second, the price of passive immune preparations was high.

A small number of people have general reactions such as fever, swelling and pain at the vaccination site after vaccination, which are mild and short-lived, and no serious adverse reactions related to the vaccine occur,There was no significant difference in the incidence of adverse reactions between pregnant women and the general population exposed to rabies.. Ongoing follow-up of infants after birth showed normal development, except for one case of mild congenital defect in Thailand (incidence rate of 6/1000 was similar to the prevalence rate of 9.5/1000 in the local general population).There was no significant difference in the incidence of adverse events between pregnant women receiving PEP and the general pregnant women.。

Some studies also tested serum antibody levels in pregnant women and infants to evaluate the effectiveness of the vaccine. The positive rate of pregnant women reached 100 14 days after vaccination, indicating that the immune effect was good. In addition, protective antibodies were also detected in some infants, indicating thatVaccination not only provides immune protection for mothers, but also for infants.。

Source: References [2-9]

Mechanisms of fetal and neonatal immune protection induced by vaccination in pregnant women

In general, all vaccines except live vaccines can be safely used in pregnant women. After pregnant women are vaccinated, they will produce humoral and cell-mediated immune responses in the body, prevent infection and reduce the risk of vertical transmission to the fetus, igG antibodies formed by the mother and transmitted to the fetus through the placental circulation (panel A) and mucosal IgG, IgA, and IgM antibodies secreted into breast milk protect the newborn from infection during the first few months of life (panel B).

Post-exposure rabies vaccination is essential for the immune protection of pregnant women. When the body is vaccinated with rabies vaccine, IgM antibody appears on the 4th day, and IgG antibody begins to be produced after 7~14 days. Both IgG and IgM antibodies have the ability to neutralize rabies virus in vitro, but the protective effect of IgM antibody in vivo is limited. IgG is the main type of antibody against rabies virus.

Rabies virus is a neurotropic virus and does not enter the blood circulation. Theoretically, it will not spread through the placenta to infect the fetus. There is no evidence of the risk of transmission from breastfeeding, but the risk of transmission from other body fluids during the perinatal period cannot be ruled out. Studies have found neutralizing antibodies induced by rabies vaccine in the umbilical cord blood of infants, indicating thatAntibodies can cross the placenta and transfer to the fetus, providing immune protection for infants in the immune gap period.。

Source: Reference [10]

Conclusion

Domestic and international studies to date indicate that,No matter in the first trimester, the second trimester or the third trimester of pregnancy, Vero cell rabies vaccine has good safety, and will not increase the incidence of miscarriage, premature birth or fetal malformation.Chengda Suda has been safely vaccinated with more than 0.4 billion doses worldwide. The vaccine is effective, safe and well tolerated. No reports of vaccine-related adverse reactions have been received in pregnant women. In clinical practice, doctors can try to eliminate unnecessary concerns about the safety of rabies vaccination in pregnant women based on existing evidence. When pregnant women are exposed to rabies, local wound treatment should be carried out as soon as possible, rabies vaccination should be carried out as soon as possible, and passive rabies immunization preparations should be used as soon as necessary.

References:

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[8] Huang G, Liu H, Cao Q, et al. Safety of post-exposure rabies prophylaxis during pregnancy: a follow-up study from Guangzhou, China[J]. Human Vaccines & Immunotherapeutics, 2013, 9(1): 177-183.

[9] Rahimi P, Vahabpour R A, Aghasadeghi M R, et al. Neutralizing antibody response after intramuscular purified vero cell rabies vaccination (PVRV) in Iranian patients with specific medical conditions[J]. PLoS One, 2015, 10(10): e0139171.

[10] Arora M, Lakshmi R. Vaccines-safety in pregnancy[J]. Best Practice & Research Clinical Obstetrics & Gynaecology, 2021, 76: 23-40.