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.
It was discovered by Belgian immunologist, Jules Jean Baptiste Vincent Bordet and Octave Gengou, a Belgian bacteriologist. They both together worked on Bordetella pertussis bacteria and claimed that it is a cause of whooping cough.The first whooping cough vaccine was produced in 1912 by Octave Gengou.hooping cough or Pertussis is a dangerous impartible bacterial disease. It is caused by âBordetella pertussisâ bacteria. It causes satirical and furious cough.