The Fraser Health Authority is stockpiling whooping cough vaccine, preparing for a possible outbreak of the highly contagious disease.

Since mid-December more than 100 cases of whooping cough — also known as pertussis — have been noted in Chilliwack, Agassiz, and Hope.

Dr. Paul Van Buynder says the health authority has purchased an extra 50,000 doses of vaccine in case the outbreak moves further west.

"We've put in place a number of contingencies in case we need to spread this beyond Fraser East and we're currently working with the Pharmacy Association and general practicioners.

"If it needs to extend beyond, we'll be able to very rapidly mobilize a workforce to deal with the problem," said Van Buynder.

Whooping cough presents like a normal cold but after a few weeks becomes a long, dry cough.

While mostly an annoyance for adults, it can be very serious for children. Half of all children suffering from whooping cough are hospitalized.

Everyone in the Fraser East region who has close contact with young children is being asked to get the vaccination, which is usually effective for between four and 10 years.

Early treatment of whooping cough with antibiotics is very effective, although it is unclear whether these have any effect in the later stages of the disease.

If left untreated, whooping cough can lead to the development of pneumonia, which can itself prove fatal.