Maternal Immunization May Protect Newborns from Whooping Cough U of S VIDO Study
May 17, 2006
In a bid to find a way to protect newborns from whooping cough, a research team at the University of Saskatchewan’s Vaccine and Infectious Disease Organization (VIDO) has shown that vaccinating pregnant sows may control the disease in newborn piglets.
The study, which used a newly developed swine model, found that piglets that suckled milk from vaccinated sows showed fewer symptoms and harboured lower numbers of bacteria than piglets borne by mothers that were not vaccinated.
The findings are published in this month’s issue of the journal Infection and Immunity.
“We showed that until the newborn is old enough to be vaccinated, we could protect it from whooping cough by immunizing the pregnant mother,” said Volker Gerdts, head of VIDO’s Neonatal Immunization Program.
As a result of the vaccine, the pregnant sows developed antibodies against the whooping cough bacteria, B. pertussis, and thenpassed the antibodies to their offspring via their milk.
While maternal immunization has been successful in the animal health industry for decades, it has not been applied to human health to the same extent, he noted.
“The value of this technique is that it may protect newborns of different species, including humans,” he said.
VIDO director Lorne Babiuk said the new method holds the potential to save millions of lives, particularly in developing countries where whooping cough, or pertussis, kills up to 300,000 children each year.
Though there are vaccines for whooping cough, newborns have immature immune systems that do not respond well to vaccination, Babiuk said.
“Newborns are the most vulnerable to infection, yet they are the least likely to be protected by vaccines,” he said. “But when newborns fall ill, they are at great risk and can spread disease to other vulnerable infants and to the community.”
In contrast to newborns, pregnant women respond well to vaccines.
The researchers used a vaccine that was made of heat-inactivated B. pertussis and was similar to commercially available vaccines.
Gerdts says that it will be several years before this technique is available for widespread use, although it is at the stage where it could be studied in humans. Pregnant mothers would be vaccinated with a commercially available vaccine, and the babies would be observed for the presence of antibodies against the bacteria.
In addition to Gerdts and Babiuk, co-authors on the study include Shokrollah Elahi (lead author) and Rachelle Buchanan.
Support for the study was provided by the following:
- A grant from the Bill & Melinda Gates Foundation and the Canadian Institutes of Health Research (CIHR) through the Grand Challenges in Global Health Initiative (http://www.grandchallengesgh.org/).
- The Krembil Foundation is a Toronto-based family foundation that supports world-class medical research. The Foundation’s gift is supporting the improvement of early-childhood vaccines by VIDO.
- The Saskatchewan Health Research Foundation (SHRF, postdoctoral fellowship to S. Elahi)
The researchers are exploring additional methods to improve immunity from B. pertussis. In another study published in last month’s Infection and Immunity, the authors found that a protein that is part of the natural immune response can protect piglets against pertussis and may be a significant weapon against other respiratory diseases.
VIDO has a long history of using maternal immunization to protect newborn animals from disease and was the first to develop maternal vaccines for the prevention of calf scours in newborn calves over two decades ago.
VIDO (www.vido.org) is a world leader in the research and development of vaccine and immunotherapeutic technologies for livestock and humans. VIDO is a financially self-reliant, non-profit organization owned by the University of Saskatchewan. It collaborates extensively with external institutes and companies and provides a rich training environment.