PITTSBURGH (KDKA) -- Christine Fabrizio was immunized with the COVID-19 vaccine in December and January.

She is pregnant and is planning to breastfeed.

"I actually breastfed my first for almost three years. I never really thought long and hard about transferring into breast milk because I knew there were no studies at that point," Fabrizio said.

A small case series awaiting peer review points to a potential benefit of immunization -- antibodies against coronavirus get into the breast milk.

"They took the women before their vaccinations and tested the breast milk for antibodies. And not surprisingly, they didn't find any," AHN obstetrician Dr. Paul Weinbaum said. "And then they tested women after their vaccination."

Among six immunized breastfeeding moms, antibodies were detected on day seven after the first dose of the vaccine.

"This is so exciting," Christine said. "This is something I would want her to have."

"This is an example of what we refer to as passive antibody transfer, which means that antibodies made by the mother transfer either, for example, to the fetus during pregnancy or to breast milk," said Dr. Weinbaum.

The baby takes in the antibodies and is protected against COVID.

Other small studies have shown the presence of antibodies against COVID in the cord blood after delivery when women have been immunized during pregnancy. This indicates these protective proteins cross the placenta to the baby.

Dr. Weinbaun says COVID immunization for pregnant and breastfeeding women can be a good thing.

"It may be well protective for the baby for a period of time as well as a result of the transfer of these antibodies," the doctor said.

For Fabrizio, this information goes above and beyond her initial expectation.

"(The vaccine) was going to protect me and my family from getting (COVID-19). Now that there's a possibility that I can protect (my baby) even after she's born. That's very exciting because there's no vaccines for infants, right now," Fabrizio said.