In my work in the obstetrics clinic, I often encounter such questions as: Can a pregnant woman get a rabies vaccination if she is accidentally scratched or even scratched by a pet? Can I get a tetanus vaccination if I get stuck by a nail or a wire? Do the vaccines have any adverse effects on the fetus? Below, I have summarized the principles of vaccine use during pregnancy in order to provide the necessary reference for the majority of pregnant women. First, the use of vaccines during pregnancy, some are allowed, some are not. Vaccines are generally divided into two categories: “inactivated vaccines” and “non-inactivated vaccines”. Inactivated vaccines mean that the microorganisms in the vaccine have been killed by chemical or physical means, but are sufficient for the body to develop immunity. Vaccines such as tetanus, for example, can be used during pregnancy. Attenuated or live vaccines are made from microorganisms that have been weakened in their ability to cause disease, and they only have to stay “alive” for the body to develop immunity. Measles vaccine and rubella vaccine are among these vaccines and are prohibited during pregnancy. Therefore, the summary is: during pregnancy, inactivated vaccines can be given, but attenuated or live vaccines are not allowed. What are the vaccines that are prohibited during pregnancy? Live attenuated virus vaccines are contraindicated during pregnancy: 1. measles vaccine 2. rubella vaccine 3. mumps vaccine 4. varicella vaccine 5. BCG vaccine In addition, there is no clear evidence that human papillomavirus (HPV) vaccination during pregnancy is harmful to the fetus. However, because the research data is not sufficient, it is recommended not to continue vaccination if pregnancy is detected. However, if you have been vaccinated during previous pregnancies, there is no need to terminate the pregnancy. III. What are the recommended vaccinations during pregnancy? During pregnancy, some viral or bacterial infections can affect the development of the fetus, therefore, the following two vaccinations are generally recommended. 1. Influenza vaccine: If you are pregnant during the high influenza season, such as between November and March, regardless of whether the pregnancy belongs to early, middle or late pregnancy, it is recommended to receive the influenza vaccine injection, because it is mostly inactivated vaccine, which is safe and effective. However, it is important to note that the influenza vaccine inhaled via the nose is a live vaccine and should be avoided according to the principles we just mentioned. If you are preparing for pregnancy during the high season of influenza and are not pregnant, both of the above flu vaccines can be used. 2.Diphtheria vaccine: Regardless of when the vaccine was given before pregnancy, it is recommended to be given again during pregnancy. This vaccine can prevent diphtheria, acellular pertussis and tetanus. The best time to get vaccinated is between 27 and 36 weeks of pregnancy, so that both baby and mother can be protected. IV. Can some common vaccines be administered during pregnancy? 1. Some vaccines can be prophylactically administered to pregnant women who are exposed to high risks. For example: Hepatitis B vaccine is a recombinant vaccine and can be administered if exposed to high risk. Hepatitis A vaccine is an inactivated virus vaccine and can be administered if there is a high risk of exposure. Pneumococcal vaccine is an inactivated bacterial vaccine and the indications for vaccination do not change due to pregnancy; the vaccine is only used for high-risk groups. 2. Some vaccines can be administered to pregnant women, but are not recommended in routine cases. For example, meningococcal vaccine is an inactivated bacterial vaccine, and the indication for vaccination does not change due to pregnancy. Typhoid vaccine is an inactivated bacterial vaccine and is not recommended during pregnancy unless there is close, continuous exposure or travel to endemic areas. 3. Some vaccines can be administered in case of unexpected conditions during pregnancy. For example: Rabies vaccine inactivated virus vaccine for prevention of dog or other animal bites and scratches can be administered during pregnancy. Tetanus toxoid is used for the prevention of contaminated wounds and can be administered during pregnancy. 4, a class of common biological agents, although not called vaccines, but can also be used for disease prevention. For example: Rabies immunoglobulin is a specific immunoglobulin used for post-exposure prophylaxis and can be given during pregnancy. It is used in conjunction with rabies vaccine. Tetanus immunoglobulin is a specific immunoglobulin for post-exposure prophylaxis and can be given during pregnancy. It is used in combination with tetanus toxoid. Varicella immunoglobulin is a specific immunoglobulin and may be considered for vaccination in healthy pregnant women exposed to varicella to protect the mother rather than to prevent congenital infection in the fetus. V. Women who are breastfeeding, which vaccines can be given? Any vaccine can be administered during breastfeeding. Breastfeeding will not affect vaccines and vaccines will not affect breast milk. VI. Vaccinations for women in preparation for pregnancy require precautions. If the vaccine given to a woman in preparation for pregnancy is a vaccine that is contraindicated during pregnancy, then it is recommended that the vaccine be given one month before pregnancy. It should be emphasized that there is no evidence that vaccination during pregnancy causes fetal health damage, and even if a live virus vaccine is contraindicated, the effect on the fetus is unknown; therefore, it is not recommended that pregnancy be easily terminated because of such vaccination.