New Brunswick Public Health officials say there are now 47 confirmed cases of whooping cough in the province, up from 36 last week.

Nearly all cases are being reported in the Greater Moncton Area, while some new cases have been reported in southeastern New Brunswick.

It’s a cause for concern for many parents in the area, including Holly Plante, whose daughter recently caught the flu.

“She's been sick with me the last couple of weeks, and that's what I was concerned about is the cough. Because it's been constant,” said Plante.

None of her three children have caught the disease, and all of them are up to date on their vaccinations. But so are many of the 47 people who have caught it, according to Public Health.

“The more time that passes since your last booster, the protection tends to drop,” says Dr. Yves Leger, New Brunswick’s Medical Officer of Health.

School-aged children receive boosters through Public Health. Plante says kids in the daycare centres she's worked at are closely monitored.

“The Public Health nurse has to come in every so often and inspect all of the immunization records,” said Plante.

It's adults who seem to be letting their immunity lapse.

“The adults, a lot of them, we're not able to get that information. Or for the small number that we did, they were not up to date,” said Leger.

Adults should get a booster every 10 years, but that can come from a number of sources, making it difficult to track.

“Ourselves and other provinces and territories have identified for a long time is a need to have not only a provincial, but a national registry,” said Leger.

Leger says they are seeing an increased demand for the pertussis vaccine and has been working to bring extra doses from other provinces.

“I’m very happy to say that, as of last Tuesday, we have received a large shipment of vaccine, which should easily be able to meet our demands, both for routine immunization, as well as increased demand,” said Leger.

Leger says that should be enough to manage the increased demand.

Pregnant women, people who are in contact with infants, and those who are nearing 10 years since their last dose should get another.

About 1,400 reports of whooping cough were recorded in New Brunswick in 2012, and Leger says the cases tend to jump every three to five years.

Health officials in Nova Scotia say they've also seen an increased number of cases, and while they're not calling it an outbreak, they urge people to ensure their vaccines are up to date.

With files from CTV Atlantic’s Sarah Ritchie and the Canadian Press.