During pregnancy, the immune system also goes through certain changes, therefore pregnant women could be more prone to certain infections potentially harmful to the fetus.
Getting vaccinated against certain infectious diseases is advised for women before their pregnancy, as during pregnancy certain vaccines are not recommended, and some can only be administered with special medical indication, after considering the risk-benefit ratio during this period.
Related article: COVID-19 vaccination during pregnancy
Immunization before pregnancy
If you are planning to get pregnant, immunization status regarding infections that you might get and that might cause harm to the fetus is recommended to be checked beforehand.
If you are planning to get pregnant, you need to be immunized against the following diseases:
- infantile paralysis,
- hepatitis B,
- chicken pox,
- whooping cough.
The system of mandatory vaccination was introduced in Hungary in 1989, so adults who had received their vaccination before that year might have different immunization status. Vaccines administered before the age of 14 are registered in the Pediatric Health Care Booklet, while vaccines administered after that are documented in the Vaccination Booklet.
The rules of immunization during pregnancy
The following rules apply to vaccination during pregnancy.
In the first trimester, vaccines can only be administered if the risk involved upon the infection is a greater threat to the pregnant woman than a potential adverse event due to vaccination.
Vaccines containing live, attenuated viruses cannot be administered at any period of the pregnancy. If you get pregnant within 4 weeks after getting vaccinated by such a vaccine, you have to consult a specialist about the inherent risks.
Vaccines containing inactivated viruses or bacteria can be administered without a risk after the first trimester, but even these vaccines should only be administered if really necessary.
Among vaccines containing the same antigen, it is recommended to choose the least probable to provoke adverse reactions.
Some vaccines needed to travel to exotic countries are not recommended during pregnancy.
Recommended vaccines during pregnancy:
- flu vaccines,
- hepatitis B vaccines.
Vaccines can be administered if the pregnant woman is at risk of the following infections:
- diphtheria, whooping cough, tetanus (DPTa) vaccine,
- hepatitis A vaccine,
- vaccine against meningococcal infection (against meningitis),
- vaccine against pneumococcal infections,
- vaccine against poliovirus,
- human papillomavirus (HPV) vaccine,
- rabies vaccine,
- typhoid-fever vaccine,
- vaccine against yellow-fever.
Recommended vaccines during pregnancy
Complications of the flu might be more severe during pregnancy, hence flu shots are recommended to every pregnant woman. Flu shots are safe and can be administered, before, throughout, and after the pregnancy. Another advantage of the flu vaccine is that it provides protection for the infant as well until around their 6-months of age.
Only inactivated virus-containing vaccines can be used, and it is recommended if the delivery is expected during flu season (end of November – beginning of March). It is advised to vaccinate people with close physical contact to the pregnant woman, since family members can easily transmit the disease to the expecting mother.
Vaccines against Hepatitis B
Hepatitis B vaccines are recommended, if the pregnant woman had multiple sexual partners in the last 6 months before getting pregnant or if they were diagnosed with a sexually transmitted disease, or if they had been regular drug users previously.
There is a high chance for the infant to get infected from the virus-carrier mother, therefore women are routinely screened at their 16th gestation week, and if necessary, the infant also gets vaccinated.
Vaccines that can be administered if the pregnant woman is at risk
The following vaccines can be administered if the woman is at great risk, increased danger of getting infected.
Diphtheria, whooping cough, tetanus vaccines
If there is a risk of tetanus infection and the woman has not been vaccinated against tetanus in the past five years, then immunization might be recommended.
Usually an acellular (which does not contain cells), trivalent vaccine is administered, hence the infant becomes protected against diphtheria and pertussis (whooping cough) as well, which is especially important, because pertussis might cause severe disease or even death in infants younger than 6 months of age.
Hepatitis A vaccines
Inactivated virus containing vaccine is administered, but there are no data available about its effects. Vaccination is recommended for those traveling to endemic regions. In Hungary, infections usually occur in children’s communities, and it is transmitted by children. Vaccinating teachers and kindergarten teachers might also be recommended.
Vaccines against meningococcal infections
Two types of vaccines are available against meningococcal meningitis, MCV4 and MPSV4. Vaccination is advised if the pregnant woman travels to endemic regions. There is no safety data available about MCV4, therefore during pregnancy it is not recommended. MPSV4 theoretically can be administered, since there have been no reported adverse events so far.
Vaccines against pneumococcal infections
Severe diseases caused by Pneumococci are meningitis, sepsis and severe pneumonia. Vaccination is recommended for those who are at great risk of developing these diseases.
Vaccines against poliovirus
The vaccine contains inactivated virus, and it is only recommended to administer if the pregnant woman is at high risk of getting infected, e.g., travel to endemic countries.
Human papillomavirus (HPV) vaccines
A quadrivalent vaccine that protects against one of the four main types of human papillomaviruses that cause cervical cancer. Adverse events have not been registered so far, but it is still not recommended to start vaccination during pregnancy.
Vaccines against rabies
Inactivated vaccine that can be administered during pregnancy after animal bites.
Vaccines against typhoid fever
The vaccine contains inactivated compounds, hence it can be administered during pregnancy if you are planning to travel to an endemic region, after consulting a specialist.
Vaccine against yellow fever
Can be administered only in specially indicated cases, e.g., urgent trips to endemic regions.
Vaccines during breastfeeding
Both live and inactivated virus-containing vaccines can be administered during breastfeeding period.