How Long Does Butter Last? How long does butter last? Butter lasts for about 6-9 months in the refrigerator and if there is a best by date stamped on the package then it will last for at least a month beyond that date, that is if it has been stored properly.
Jonas Salk is credited with developing the first polio vaccine in 1955, an injected vaccine containing killed virus, but the oral live vaccine devised a little later by his competitor Albert Sabin is the workhorse of the Global Polio Eradication Initiative.onas Salk is credited with developing the first polio vaccine in 1955, an injected vaccine containing killed virus, but the oral live vaccine devised a little later by his competitor Albert Sabin is the workhorse of the Global Polio Eradication Initiative.
1 Immunization. 2  The inactivated polio vaccine (IPV) used today in the United States stimulates the immune system to produce antibodies that fight the polio virus if a person comes in contact with it. 3  Dr. Jonas Salk developed the first IPV in 1955, and an enhanced-potency version came about in 1988. Other parts of the world use an oral polio vaccine (OPV) that was first developed by Dr. Albert Sabin in 1961. 2  OPV is based on a live, but weakened, form of the virus.