In California, Tdap coverage during pregnancy increased substantially in 2010 and 2011, but decreased in 2012 (16% vs. 30% vs. 19.5%), likely because many women had received Tdap prepregnancy, she said. Prepregnancy vaccinations climbed steadily from 21.5% in 2010 and 35.3% in 2011 to 53.8% in 2012.
In 2010, the California Department of Public Health began recommending that all women of childbearing age be vaccinated with Tdap.
A protocol looking at repeat Tdap vaccinations and repeat pregnancies has already been written and is being led by CDC investigators, Dr. Kharbanda said.
Dr. Kharbanda reported study support from the CDC VSD project.