In Sweden, about 20 infants aged <?2.5?months were hospitalised for pertussis each year from 2008 to 2011 , which provides an age-specific incidence of about 100 per 100?000. A resurgence of pertussis in infants and a shift of cases from preschool children to adolescents, and even young adults, has been documented in most western countries [1, 2]. The shift is due to booster vaccinations given at preschool and school ages. Possible reasons for the re-emergence of pertussis in well-vaccinated populations include increased awareness of the disease, activated surveillance, use of the <a href="http://www.selleckchem.com/products/MG132.html
">MG-132 mouse highly sensitive polymerase chain reaction (PCR) for diagnosis and genetic changes in circulating B.?pertussis strains under the selective vaccination pressure [1, 4]. Although booster vaccinations are currently offered after infancy, coverage at preschool age, and especially at school age, is less than coverage of the primary series in infancy. In addition, the waning of immunity may be faster in those vaccinated with the acellular vaccine, which contains PFI-2
fewer antigens than the previous whole-cell vaccine. Recent animal experiments even suggest that although acellular pertussis vaccine protects against the disease, it fails to prevent infection and transmission . The risk of an increasing occurrence of pertussis in young adults, including mothers and fathers of newborns babies, has been recognised in many countries and pertussis vaccinations are currently offered to pregnant women in parts of the United States and in the United Kingdom and the Netherlands and to all adults in France and Canada . We have known for some time that other household members are a common source of pertussis infections and that mothers, in particular, are responsible for transmitting pertussis to infants in more than 75% of cases [4, 5]. The most beneficial time to vaccinate pregnant women is the second half of pregnancy, because the immunoglobulin G transport through the placenta is most efficient during the third trimester. Safety data on vaccinating pregnant women check details
are limited, but the registers have not revealed any alarming safety signals . Starting vaccinations at two months of age instead of the current 3?months in some countries would decrease the susceptible infant population by a third. However, vaccinating newborns may interfere with the responses to other vaccines given in infancy and, therefore, it is currently not recommended . An important adult target group who is insufficiently vaccinated is staff working with newborns and unvaccinated infants.