The Pfizer and Moderna COVID vaccines are mRNA (messenger RNA) vaccine. The material in the vaccine contains instructions for the body to make a small part of the virus called the spike protein. When these proteins are made, the immune system is called into action. The body then begins to make antibodies against the spike protein.
This response can lead to common side effects such as body aches, soreness in the arm and in some cases a low-grade fever. These symptoms usually are mild to moderate and last for 1-3 days after the vaccine.
The mRNA is quickly broken down and eliminated from the body. To be clear, it’s not possible to get COVID-19 from the vaccine. The mRNA vaccines do not contain live virus, they do not enter the nucleus of the cell and do not cause any genetic changes.
Pregnant and breastfeeding women were not included in the recent vaccine trials; however, future studies are expected to include pregnant patients. Some women in the studies did become pregnant during the trials and there was no increased risk of miscarriage among these women. In addition, the Moderna vaccine also the tested the vaccine with pregnant rats and did not show any negative effects on fertility or fetal development. Based on the way the vaccine works it’s anticipated that the safety and efficacy of the vaccine will be similar to what was seen in non-pregnant patients.
Data suggests the vaccines are 95% effective and the full efficacy is achieved 1-2 weeks after the second vaccine dose is administered. In other words, 95% efficacy means that for every 100 unvaccinated people who get COVID-19, only 5 vaccinated people will actually get the virus. In addition, the severity of the illness is likely to be less for those who get the virus after receiving the vaccine.
Deciding if and when to get the COVID-19 vaccine is a personal choice for every pregnant woman. Start by having a conversation with your doctor or healthcare provider who can provide the most current information regarding the vaccine. You should also consider how active the virus is in your community (it’s currently high in most communities in Utah), how well the vaccine works, your risk for COVID-19, and the safety data about the vaccine.