COVID-19 vaccines during pregnancy

Pregnancy is a condition when women are more prone to infections due to physiological changes in their bodies, therefore their protection is very important.

In the beginning, since we had very little knowledge and experience about COVID-19, it was not clear whether the potential vaccine reactions or the complications of the infection itself pose a greater threat to pregnant women and their fetuses. Today, however, we have ample international data that supports COVID-19 vaccination during pregnancy, since the risk of vaccination has been proven to be insignificant compared to that of the infection.

Vaccination during pregnancy is not only advantageous for and protects only the mother, but it is also beneficial for the baby. The immune protection against COVID-19 (the IgG antibodies produced by the mother’s immune system) gets into the fetus’s body through the placenta. These antibodies can be detected in newborns and infants in a long term. This is a natural form of passive immunity.

When getting vaccinated, individual risk factors and risk/benefit ratio obviously need to be considered (other diseases, ongoing treatments, etc.). After that, with the help of the obstetrician/gynecologist and the doctor in charge of vaccination, pregnant women can decide on whether they want to be vaccinated.

Information on COVID-19 vaccination during pregnancy

COVID-19 vaccines are available and recommended for pregnant women. Vaccines’ safety data have been collected and evaluated internationally and continuously since the beginning of COVID-19 vaccination.

Pregnant women are considered to be at extremely high risk if they have an underlying disease, especially if they receive immunosuppressant therapy due to previous organ transplantation or autoimmune disease, asthma, COPD or other severe respiratory diseases, sickle cell anemia, chronic kidney failure, heart failure or diabetes.

The following recommendations prevail for pregnant women:

• mRNA vaccines are recommended most commonly, since the majority of clinical trials and international data have been related to these vaccines, hence we have more reliable medical evidence on them (Pfizer-BioNTech and Moderna vaccines).

• The most adequate time for immunization is in the 2^nd and 3^rd trimester, however, if the woman is at great risk of COVID-19 infection, vaccination can be started during the 1^st trimester, too.

• The primary series of vaccination should be started before the 35^th week of pregnancy: if the 2^nd or 3^rd vaccine would be due after the 35^th week, the vaccination is advised to be started after giving birth.

• Vaccines that do not contain pathogens are not considered a risk during breastfeeding, therefore getting vaccinated with these types of vaccines are not contraindicated during breastfeeding.

• The 3^rd (booster) vaccine is recommended if the pregnant woman is at greater risk of COVID-19 infection due to an underlying disease or her occupation (but after the 35^th week of pregnancy it is advised to wait until after giving birth).

In Hungary, Pfizer-BioNTech and Moderna vaccines are available for pregnant women from the 12^th week of pregnancy in the 2^nd trimester. The 2^nd vaccine is advised to be administered before the 36^th week of pregnancy, based on the recommendations and considerations of their obstetrician/gynecologist doctor.

If pregnant women only get the first shot during pregnancy, the 2^nd vaccine can be administered in the 2^nd week after delivery. However, it is not advised to start vaccination in a timing that does not allow the full series (two doses) of vaccinations to be received before giving birth (see recommendations above).

You can register for the vaccination via the “Vakicinainfo” website, then contact your GP or treating physician.

COVID-19 vaccine’s safety during pregnancy

COVID-19 vaccines’ safety has been continuously monitored (observed) since the beginning of COVID-19 vaccination by different international pharmaceutical authorities.

Among others, the following international studies have been conducted on the COVID-19 vaccine’s safety:

• PRAC.This is the side effect monitoring system of the European Medicines Agency (EMA) which continuously monitors and evaluates the dangers and side effects of vaccines

• VAERS (Vaccine Adverse Event Reporting System).This is a national system to which manufacturers, medical employees, and citizens can report the complications that occur after vaccination, and researchers investigate reports of more frequent complications or of complications that show an unusual pattern. Besides, clinicians examine all reports in connection with pregnancy (CDC and FDA).

• V-safe. Smartphone-based, vaccination tracking and post-vaccine condition controller, with which registered users can fill out questionnaires after each vaccine. Through the registry, the CDC controls vaccine safety in different populations (including pregnant women).

• Birth Defect Study to Evaluate Pregnancy Exposures. An ongoing project that investigates potential birth defects (17 types) and their causes (e.g., if they are related to vaccination). Currently, the results are not yet published (CDC).

• VSD (Vaccine Safety Datalink). Network of several healthcare organizations in the USA, which monitors and evaluates vaccine safety. They also check whether the reported side effect is indeed in connection with the vaccination (CDC).

• Clinical Immunization Safety Assessment (CISA) Project. A project arising from the cooperation of the CDC and different healthcare research institutes, which integrates the data related to pregnant women’s vaccinations.

COVID-19 vaccine side effects in pregnant women

As all vaccines, COVID-19 vaccines can also have side effects, since they might trigger a so-called vaccination reaction, which is part of the natural immune response. In most cases, this means transient, mild symptoms which resolve on their own within a short period of time.

COVID-19 vaccines’ side effects in pregnant women comply with those noted in adults.

Vaccine side effects have been continuously monitored by different authorities.

Vaccine reaction symptoms can be the following:

• pain, redness or swelling of the skin at the injection site;
• transient fatigue, weakness, light-headedness;
• headache, nausea;
• subfebrility or fever.