For the first time ever, the American College of Obstetricians and Gynecologists (ACOG) has published its own independent vaccine schedule for pregnant patients, sparking a historic disagreement with federal health agencies. This move comes after the Department of Health and Human Services (HHS) and the CDC shifted their stances, walking back standard recommendations for the COVID-19 and flu shots during pregnancy.

In response, ACOG teamed up with 13 other major medical organizations (including pediatricians and family doctors) to reinforce recommendations grounded purely in peer-reviewed science, aiming to clear up public confusion and counter misinformation. Ultimately, this new medical independence provides a trusted, evidence-backed pathway for expectant parents, making it easier to ensure that both mothers and their newborns get the crucial immune protection they need during the first few months of a baby’s life.

The science behind maternal immunization

Maternal immunization is a very specialized preventive health measure that involves the mother’s immune system to create a biological barrier for her unborn child, the CDC explains. When a baby is born, its immune system is very weak and begins to mature in an environment filled with hostile pathogens. They’re unable to produce their own protective antibodies for several months, making them susceptible to life-threatening respiratory infections.

Maternal vaccines take advantage of a natural biological pipeline, called transplacental antibody transfer, according to the National Institutes of Health (NIH). If a pregnant woman is injected with a harmless protein (inactivated) or an mRNA molecule (safe), her immune system gets the signal and starts producing the appropriate IgG antibodies.

Tunde Rasheed, B.Sc. Researcher in Chemical and Polymer Medical Engineering tells Blavity Health, “These protective proteins pass straight across the umbilical cord and into the fetus’s bloodstream. This cellular transfer is active and assures a baby will be born with a strong ‘baseline’ of passive immunity, shielding the infant from serious illness until they can receive their own childhood immunizations.”

What vaccines are recommended during pregnancy?

ACOG’s independent clinical guidelines outline four routine vaccines, regardless of a patient’s prior immunization history.

• Influenza vaccine: ACOG strongly recommends getting a flu shot (inactivated or recombinant) in any trimester of pregnancy. The ideal time for the injection is by the end of October to provide full protection before seasonal respiratory viruses are in full swing in the community.
• COVID-19 vaccine: In stark contrast to the current CDC recommendations, ACOG recommends routine COVID-19 vaccination for all pregnant, postpartum and lactating people using the updated COVID-19 vaccines. Physicians stress the importance of taking the shot as soon as possible during a pregnancy to help ensure the best possible health for both mother and child.
• Tdap vaccine: This combination vaccine is used for protection against tetanus, diphtheria and whooping cough (pertussis). It should be given for each pregnancy, ideally early in the 27-36 weeks’ gestation window, to maximize antibody transfer before birth.
• RSV vaccine: To prevent infants from respiratory syncytial virus, ACOG recommends giving Pfizer’s Abrysvo vaccine once between 32 and 36 weeks of pregnancy, seasonally from September to January in most of the continental U.S.

Why safety is a concern

Expectant mothers are bound to become more sensitive to substances entering their bodies during pregnancy, and this is perfectly natural. The placenta is a very fragile and discriminating barrier, and it is not surprising that families are concerned that something in the vaccine might “cross the barrier” and somehow interfere with fetal development.

This fundamental unease has been exacerbated by shifting recommendations from federal officials and misinformation campaigns online, which many people are now using to dispute medical advice.

The medical profession has made it clear that any risk must be weighed against the potential for a “wild” infection during pregnancy, which is quite a real and serious risk. During pregnancy, there are natural changes in a woman’s cardiovascular, respiratory and immune systems that place extra stress on her lungs and heart, explains the Cleveland Clinic. Influenza and COVID-19 have significant risks for severe maternal morbidity, ICU admission and respiratory failure if contracted during pregnancy, making proactive defense a clinical imperative.

Risks and side effects of maternal vaccines

As with all clinical interventions, maternal immunizations have a predictable spectrum of minor post-immunization side effects that represent a normal immune response.

The Mayo Clinic reports that almost all side effects of the maternal vaccines are temporary and perfectly safe for the baby. These symptoms usually occur within 24-48 hours, as the mother’s immune cells begin processing the vaccine and producing antibodies.

The most common side effect reported across all maternal platforms is localized pain, mild swelling or a firm knot at the injection site on the upper arm. This localized reaction simply proves that the body’s local immune cells are actively gathering to interpret the vaccine.

Some people who are pregnant can experience low-grade side effects that are systemic, such as mild headaches, muscle aches, low-grade fevers or shortness of breath or tiredness. These are transient and resolve on their own within a few days, leaving no permanent scars on the mother or child.

What vaccines should be avoided during pregnancy?

Some vaccines are contraindicated during pregnancy because they may pose risks to the fetus, although inactivated, recombinant and mRNA vaccines are very safe.

The CDC guidelines indicate that live-attenuated vaccines should be avoided during pregnancy. Live vaccines contain live, but weakened, forms of a virus and could potentially cross the placenta and cause infection in a developing fetus. Live shots contraindicated include Varicella (chicken pox), Human Papillomavirus (HPV) and Measles-Mumps-Rubella (MMR). Certain immunizations will need to be rescheduled for the postpartum period.

Furthermore, although the CDC has recommended that only thimerosal-free influenza vaccines be used in pregnant women, ACOG’s expert committee reiterates that thimerosal-containing vaccines are safe and should not be postponed if thimerosal-free vaccines are unavailable.

Safer alternatives and best practices

When it comes to immunizations, there are many options to consider. If you’re an expecting mother and need to follow a complicated schedule of vaccines, make sure to follow good clinical practices to get through the pregnancy safely and comfortably.

The gold standard for maximizing infant protection against RSV is an important clinical decision. When a mom takes the Pfizer RSV vaccine (Abrysvo) during her pregnancy, her baby will be protected. If, however, the mother has previously received the RSV vaccine, or if she decides to skip maternal vaccination, the baby would need to be vaccinated with a monoclonal antibody injection (Nirsevimab) shortly after birth as a safer alternative to provide early lung protection.

Ask your Ob-Gyn or midwife to review your full immunization record at your first prenatal visit and provide you with a personalized immunization schedule. When your Tdap and seasonal vaccines are given at the exact time they are needed, your body produces the highest levels of antibodies at the critical time when your baby needs them.

How to decline vaccines while pregnant

Every patient has absolute legal authority over their body, and this includes the right to decline any medical procedure, including maternal vaccinations. When a recommended vaccine is declined, the best option is to begin a candid, open discussion with your obstetric care provider.

Make it clear what you are worried or anxious about so that your provider can provide you with information to address your concerns. If you refuse, your doctor will request a standard medical refusal waiver to be signed and record this in your electronic chart. If you decide against it, you will have to use other infection-control measures more diligently, including maintaining careful hand hygiene, avoiding crowded indoor areas during the respiratory season, and ensuring that family members caring for the newborn are fully immunized to form a protective cocoon around the baby.

“Changing national recommendations coupled with rampant vaccine misinformation are resulting in confusion for both patients and health care professionals,” Dr. Camille Clare,MD, MPH, CPE, ACOG president, said in a statement. “It is incredibly important for the public to have access to reliable, evidence-based information on maternal immunizations from a trusted source.”

Bottom line

The American College of Obstetricians and Gynecologists launched its own 2026 Maternal Immunization Schedule, which contradicts the CDC’s recommendations to routinely vaccinate all pregnant people against influenza and COVID-19. Along with the universally accepted Tdap and RSV vaccines, these shots are given to the mother and sero-transferred to newborns, providing them with life-saving passive immunity during their first vulnerable months. With trusted advice from an OB-GYN at the outset of pregnancy, awareness of the gestational windows, and knowledge of how to avoid live-attenuated preparations, women can safely “shop” their options and help ensure the best possible start for their little one.

Frequently Asked Questions

What happens if you don’t get Tdap while pregnant?

If you skip the Tdap vaccine during pregnancy, your newborn will be born with zero passive antibodies against pertussis (whooping cough), heavily increasing their risk of severe respiratory failure if exposed to the bacteria before their two-month checkup.

Can Tdap cause preterm labor?

Extensive, real-world tracking datasets maintained by global health organizations show absolutely no statistical link between receiving the Tdap vaccine and experiencing preterm labor or placental complications.

Citations

CDC. Why Maternal Vaccines Are Important. Pregnancy and Vaccination. Published 2024. https://www.cdc.gov/vaccines-pregnancy/hcp/maternal-vaccines/index.html

Chittajallu LVS, Kaku R, Kondadasula P, Lim JY, Zhumabekova A. Safety and Efficacy of Vaccines During Pregnancy: A Systematic Review. Cureus. Published online January 9, 2025. doi:https://doi.org/10.7759/cureus.77176

Cleveland Clinic. Heart Disease & Pregnancy. Cleveland Clinic. Published August 4, 2022. https://my.clevelandclinic.org/health/diseases/17068-heart-disease–pregnancy

Mayo Clinic. Vaccines: tough questions, straight answers. Mayo Clinic. Published March 28, 2023. https://www.mayoclinic.org/healthy-lifestyle/infant-and-toddler-health/in-depth/vaccines/art-20048334

CDC. Pregnancy and Vaccines. Vaccine Safety. Published August 6, 2024. https://www.cdc.gov/vaccine-safety/about/pregnancy.html