http://www.cdc.gov/vaccines/pubs/surv-manual/chpt01-dip.html http://www.cdc.gov/vaccines/pubs/surv-manual/chpt01-dip.html Diphtheria http://www.cdc.gov/vaccines/pubs/surv-manual/chpt01-dip.html Diphtheria http://www.cdc.gov/vaccines/pubs/surv-manual/chpt01-dip.html http://www.cdc.gov/vaccines/pubs/surv-manual/chpt01-dip.html