While the effectiveness of vaccination has been overwhelmingly and repeatedly proven, there are a few very specific circumstances where caution is sometimes advised by clinicians.
One of these concerns women who become pregnant while taking one of a new class of “biological” immune-suppressant drugs called bDMARDs. Typically used to treat autoimmune conditions including Crohn’s disease, ulcerative colitis, rheumatoid arthritis, lupus and psoriasis, there is the potential that bDMARDs might reduce the effectiveness of vaccinations routinely given to pregnant women.
It is also possible that the drugs might pass on to their babies in utero, supressing their immune response and requiring an adjustment to the vaccination regime of newborns and infants.
University of Sydney Associate Professor Nicholas Wood, who heads the NSW Immunisation Specialist Service at Childrens Hospital Westmead, is leading a Sydney Health Partners-funded project which aims to produce data to guide the vaccination of this specific group of women and their babies.
He says the research will address a lack of evidence, which has made it difficult for clinicians to advise prospective mothers.
“Maternal vaccination against influenza and whooping cough is our primary strategy to prevent these infections in young infants,” says Associate Professor Wood, “but information regarding its safety and effectiveness for women taking immunosuppressive drugs is lacking, mainly because they are routinely excluded from drugs trials.”
“With the bDMARDs class of medications expanding rapidly and being used by more and more women, it’s important that we address the evidence gap.”
The project is recruiting a cohort of pregnant women using immunosuppressive drugs through three major hospitals across the Sydney Health Partnership, plus Monash Hospital in Melbourne. They will be tested for their antibody response to the flu and whooping cough vaccinations. Their response will be compared to a group of healthy women.
In addition, by the time the project concludes in 2020, the babies of these women will also have been tested for their antibody response to routine infant vaccinations.
It is intended that the research project will result in the creation of new clinical guidelines to be used in high risk maternity clinics.
Researchers have produced a simple advice pamphlet for women attending such clinics.
“The content and style of the pamphlet was refined through feedback from obstetricians who are part of the research team, and as a result, referrals to the NSW immunisation Specialist Service have occurred,” said Associate Professor Wood.
“It’s an important result because prior to this, if a pregnant woman on immunosuppressive drugs, or her doctor, wanted vaccination advice, there really wasn’t much available.”