became available in the USA in 1948 became available in the USA in 1948 became available in the USA in 1948 History of the Pertussis Vaccines became available in the USA in 1948 became available in the USA in 1948 in 1948 became available in the USA in 1948 became available in the USA in 1948 became available in the USA in 1948 became available in the USA in 1948 became available in the USA in 1948 became available in the USA in 1948 in 1948 History of the Pertussis Vaccines became available in the USA in 1948 became available in the USA in 1948 50,000 infections History of the Pertussis Vaccines became available in the USA in 1948 became available in the USA in 1948 became available in the USA in 1948 became available in the USA in 1948 became available in the USA in 1948