TORONTO (Reuters) - Canada suspended use of three batches of a mumps vaccine on Wednesday after five people fell ill in the midst of a vaccination campaign in the western province of Alberta.
Health Canada advised against the use of the three lots of measles, mumps and rubella vaccine sold by MerckFrosst Canada, while it investigates five suspected cases of anaphylaxis, a potentially life-threatening allergic reaction characterized by swelling and difficulty breathing.
All five cases involved adults aged 20 to 30 in Alberta who had a previous history of allergy. All have fully recovered.
Canadian officials are now trying to determine if the vaccine may be having the same adverse reaction elsewhere.
A joint investigation by Health Canada, the Public Health Agency of Canada and Health Alberta is being carried out in conjunction with distributor MerckFrosst Canada. It is soliciting reports of adverse effects from other countries that use the measles, mumps and rubella vaccine MMR-II.
Parent Merck & Co Inc markets the vaccine in the European Union, Australia, Hong Kong, China, Argentina, Russia, the United States, and elsewhere.
“Because all of our vaccine producers now are all global, then we also reach out globally to determine whether or not there are any other adverse events or clusters of adverse events that people are seeing elsewhere related to this product, or related to any of these lots that may be gone elsewhere,” said Dr. Arlene King, a director with the Public Health Agency.
King said Canadian officials would also be contacting regulatory authorities in other countries.
“It will probably be several weeks before we have a complete analysis of both the adverse events and the product,” she added.
“This is very unusual. Millions and millions of doses of this vaccine have been given around the world so really this vaccine is very safe,” said Sheila Murphy, manager of public affairs for vaccines at MerckFrosst Canada Ltd.
“We are, from our side, looking at globally whether we have any reported cases of anaphylaxis and from the manufacturing side whether there has been any anomaly in the production of the vaccine,” Murphy said.
The vaccine is normally given to children twice in their second year of life, but due to mumps outbreaks across Canada, a catch-up campaign was under way in Alberta, primarily for young adults in post-secondary schools.
Mumps can cause sterility, meningitis and deafness. In August a national advisory committee urged all Canadians up to about age 40 to get two doses of mumps vaccine.
Since 1978, more than 500 million doses of MMR-II have been distributed worldwide, Murphy said. It is also on the regular childhood and baby vaccination schedule in Canada.
“Cases have been related to one lot in Alberta and they’re amongst these young adults, so there’s been no reported cases with the babies,” she said.
Reporting by Carla Tonelli; Editing by Rob Wilson