Study provides evidence of four early doses of pertussis vaccine
Protection from three doses of pertussis vaccine against disease requiring hospitalization waned significantly even by 4 years of age, Australian researchers reported yesterday in Pediatrics, a finding that supports current US recommendations of four early doses.
The investigators matched all 1,446 pertussis patients aged 2 to 47 months reported from January 2005 through December 2009 in Australia with 28,828 controls to analyze vaccine effectiveness (VE) for the diphtheria-tetanus–acellular pertussis (DTaP) vaccine.
They found that VE against pertussis hospitalization dropped from 83.5% (95% confidence interval [CI], 79.1%-87.8%) between 6 and 11 months of age to 70.7% (95% CI, 64.5%-75.8%) between 2 and 3 years of age. VE dropped even further, to 59.2% (95% CI, 51.0%–66.0%), between 3 and 4 years of age.
The team also found that VE against hospitalization increased from 55.3% (95% CI, 42.7%-65.1%) for one dose before 4 months of age to 83.0% (95% CI, 70.2%-90.3%) for two doses before 6 months.
Children in Australia receive a fourth "booster" dose at 4 years. US kids are recommended to receive four doses by age 18 months, with a fifth dose from 4 to 6 years of age.
The authors conclude, "Without a booster dose, the effectiveness of 3 doses waned more rapidly from 2 to 4 years of age than previously documented for children >6 years of age who had received 5 doses."
Feb 10 Pediatrics abstract
First polio case in 13 years reported in Kabul
A 3-year-old girl in Kabul, Afghanistan, has been diagnosed as having polio, the first case in that nation's capital in 13 years, CNN reported today.
An Afghan Health Ministry spokesperson said the girl's case is the first in Kabul since 2001, and he added that officials have started an immunization campaign in the city. The case is Afghanistan's second this year, compared with 14 in all of last year.
Feb 11 CNN report
In other polio news, one policeman was killed today and another critically wounded when gunmen opened fire on a vaccination team in the Dera Ismail Khan district of Khyber Pakhtunkhwa province in the rugged northwest part of Pakistan, according to Pakistan Today.
The officers were providing security to health workers administering polio vaccine in the area when the assailants fired on them. No health workers were injured.
No group immediately claimed responsibility, but the extremist Muslim group Tehreek-e-Taliban has been repeatedly involved in previous attacks on polio immunization workers, the story said. The region has been targeted by militants who perceive the campaigns as Western subterfuge.
Feb 11 Pakistan Today story
