Overall, filibustering and U.S. policies seem to have hindered more than helped U.S. attempts at territorial expansion in this time period. The Gadsden Purchase was the only official territorial acquisition during the 1850s.
Acellular pertussis vaccines were introduced nation-wide in Sweden in 1996, 17 years after the withdrawal of whole-cell pertussis vaccine from the childhood immunisation schedule.he annual incidence of culture-confirmed B. pertussis was 89-150 per 100,000 before introduction of acellular pertussis vaccines and has dropped to 17-26 per 100,000. The data suggest that unimmunised infants and children who have received only one dose of pertussis vaccine were provided some protection.
Vaccine Basics. There are four combination vaccines used to prevent diphtheria, tetanus, and pertussis (whooping cough): DTaP, Tdap, DT, and Td. Two of these (DTaP and DT) are given to children younger than seven years of age and two (Tdap and Td) are given to older children and adults.