David Baxter PhD
Late Founder
Vaccine reactions are 'very rare'
CBC News
Jan 23, 2012
A sudden, serious allergic reaction known anaphylaxis is "extremely rare" after childhood vaccinations, a U.K. study suggests.
Anaphylaxis can be fatal and can be triggered by specific foods, airborne allergens, stings and bites, and drugs or vaccines.
Since the reactions are so rare, they often doesn't turn up as a potential side-effect during clinical trials of a new drug.
To find out more, Dr. Mich Lajeunesse of the Children's Allergy Clinic in Southampton, U.K., and his co-authors analyzed cases of suspected anaphylaxis that were reported to British health authorities in 2008 and 2009.
"This is extremely reassuring data for the general public and health-care workers alike," they concluded in Monday's online issue of the Archives of Disease in Childhood.
For the study, Lajeunesse's team reviewed data on 15 suspected cases that were reported to pediatricians, involving children under the age of 16, including:
Only seven of the cases were confirmed as anaphylaxis.
Six children needed an injection of adrenaline and intravenous fluids. All recovered fully. One child recovered without treatment, the researchers said.
Given that more than 16,000 doses were delivered, the incidence was 12 cases of anaphylaxis for every 100,000 doses, they estimated.
Three of the cases were associated with the HPV vaccine.
Symptoms began within 15 minutes in three cases, but four episodes occurred 30 minutes or more following immunization —later than generally thought, the journal's editors noted. In one case, the reaction occurred two hours after the shot.
For children with a previous history of anaphylaxis with no known cause, it may be appropriate to use a longer observation period of up to 60 minutes, the team suggested.
There were no reports of anaphylaxis after routine preschool and infant vaccines, including measles, mumps and rubella (MMR) and influenza vaccines.
"Anaphylaxis remains a very rare adverse event following immunization," the study's authors concluded.
CBC News
Jan 23, 2012
A sudden, serious allergic reaction known anaphylaxis is "extremely rare" after childhood vaccinations, a U.K. study suggests.
Anaphylaxis can be fatal and can be triggered by specific foods, airborne allergens, stings and bites, and drugs or vaccines.
Since the reactions are so rare, they often doesn't turn up as a potential side-effect during clinical trials of a new drug.
To find out more, Dr. Mich Lajeunesse of the Children's Allergy Clinic in Southampton, U.K., and his co-authors analyzed cases of suspected anaphylaxis that were reported to British health authorities in 2008 and 2009.
"This is extremely reassuring data for the general public and health-care workers alike," they concluded in Monday's online issue of the Archives of Disease in Childhood.
For the study, Lajeunesse's team reviewed data on 15 suspected cases that were reported to pediatricians, involving children under the age of 16, including:
- Measles vaccination.
- HPV vaccination to protect against cervical cancer.
- Two types of vaccine for meningitis.
- Hepatitis A vaccine.
- Typhoid vaccine.
Only seven of the cases were confirmed as anaphylaxis.
Six children needed an injection of adrenaline and intravenous fluids. All recovered fully. One child recovered without treatment, the researchers said.
Given that more than 16,000 doses were delivered, the incidence was 12 cases of anaphylaxis for every 100,000 doses, they estimated.
Three of the cases were associated with the HPV vaccine.
Symptoms began within 15 minutes in three cases, but four episodes occurred 30 minutes or more following immunization —later than generally thought, the journal's editors noted. In one case, the reaction occurred two hours after the shot.
For children with a previous history of anaphylaxis with no known cause, it may be appropriate to use a longer observation period of up to 60 minutes, the team suggested.
There were no reports of anaphylaxis after routine preschool and infant vaccines, including measles, mumps and rubella (MMR) and influenza vaccines.
"Anaphylaxis remains a very rare adverse event following immunization," the study's authors concluded.
