Salk polio vaccine

One of the largest trials ever conducted took place in the US in 1954 and concerned the evaluation of the Salk Polio Vaccine. The trial has been reported extensively by Meier (1978) and is used by Pocock (1983) in his discussion of the historical development of clinical trials. 

The randomised part of the Salk Polio Vaccine trial has all the hallmarks of modern day trials randomisation, control group, blinding and it was experiences of these kinds that helped convince researchers that only under these conditions can clear, scientifically valid conclusions be drawn. 

Killed or inactivated vaccines contain dead cells of the bacteria or vims that causes the disease to be prevented. Examples include the Salk polio vaccine and the pertussis vaccine. 

Polio is the only disease, at present, for which both hve and killed vaccines compete. Since the introduction of the killed vims (Salk) in 1956 and the live attenuated virus (Sabin) in 1962 there has been a remaikable decline in the incidence of poliomyelitis (Fig. 16.1). The inactivated polio vaccine (TPV) contains formalin-killed poliovirus of all three serotypes. On injection, the vaccine stimulates the production of antibodies of the IgM and IgG class which neutrahze the vims in the second stage of infection. A course of three injections at monthly intervals produces long-lasting immunity to all three poliovirus types. 

In the 1950s, Dr. Jonas Salk and Dr. Albert Sabin from the University of Pittsburgh (USA) worked on polio vaccines. Salk used inactivated polio virus, whereas Sabin developed a live form of polio virus. 

The original polio vaccine was developed by Jonas Salk (for whom the Salk Institute in LaJolla is named). It is a "killed" virus. However, over the years it was found that this did not always impart a complete immunity. The Sabin vaccine contains an attenuated virus. It is interesting to note that the Sabin vaccine can cause an active infection in a rare number of cases. 

Jonas Salk (1915-1995) begins testing a polio vaccine comprised of a mixture of killed viruses. 

The World Health Organization advances the oral polio vaccine developed by Albert Sabin (1906-1993) as a safer alternative to the Salk vaccine. 

The first non dye-based drug company was in fact Hungarian. Gideon Richter is still famed for its production of steroid-based drugs. Another, Chinoin, is part of Sanofi. The Soviet Union s Jonas Salk, Ilya Sabin, produced Sabin drops simultaneously with Salk s polio vaccine. Countries such as Finland adopted the Sabin drops in preference to Salk s injection. 

The single-component viral vaccines are listed in Table 23.2 with notes similar to those provided with the bacterial vaccines. The only combined viral vaccine that is widely used is the measles, mumps and rubella vaccine (MMR Vac). In a sense however, both the inactivated (Salk) poliovaccine (Pol/Vac (inactivated)) and the live (Sabin) polio-vaccine (Pol/Vac (oral) are combined vaccines in that they are both mixtures of virus of each of the three serotypes of poliovirus. Influenza vaccines, too, are combined vaccines in that they usually contain components from several virus strains, usually from two strains of influenza A and one strain of influenza B. 

An inactivated trivalent vaccine developed by Jonas Salk was licensed for use in 1955. In 1987, an enhanced-potency inactivated poho vaccine (IPV) was introduced, and it has replaced the original inactivated vaccine. A live attenuated oral polio vaccine (OPV) was developed by Albert Sabin in 1962. OPV was the primary immunizing agent for poliovirus infection. Widespread OPV use is responsible for eradication of wild-type polio in most of the world. However, with no poliovirus circulation in the United States for years, IPV is the recommended vaccine for the primary series and booster dose for children. OPV will continue to be used in the areas of the world that have circulating pohovirus. The CEX7 maintains a stockpile of OPV to be used only in case of an outbreak. ... 

Formaldehyde is useful in the production of killed virus vaccines. A deadly virus, such as polio virus, can be treated with heat and formaldehyde. Formaldehyde reacts with the genetic information (RNA) of the virus, damaging it irreparably. It also reacts with the virus proteins but does not change their shape. Thus when you are injected with the Salk killed polio vaccine, the virus can t replicate and harm you. However, it will be recognized by your immune system, which wiU produce antibodies that will protect you against poUo virus infection. 

On 1st February 1951 Flenrietta Lacks, who was suffering from cervical cancer, had - without her consent - samples of her cervix removed at the Johns Hopkins Hospital In Baltimore. She deceased on 4th October of the same year. A subset of her malignant cells was characterised and found to divide beyond the normal limit. From a single of these cells, researchers were able to establish the first Immortal human cell line, which they labelled HeLa-cells, in memory of the donor. From 1952 right up to the present time, this cell line is used worldwide for research purposes, as e.g. for the development of the polio vaccine by Jonas Salk at the University of Pittsburgh School of Medicine, which underwent clinical trials already in 1954. 

Vaccines, which nsnally involve viruses or nucleic acids in some way or another, have been known since Jenner nsed cowpox virns against smallpox in 1796. This was followed by Pasteur, who developed a rabies vaccine in 1885. The best-known twentieth-century vaccine is probably the anti-polio vaccine introduced by Salk in 1954. Vaccines exist to prevent diseases caused by either bacteria or viruses. 

PoUo vaccine ([onas Salk) Salk s polio vaccine, which uses the killed virus, saves lives and improves the quality of life for millions afflicted by polio. 

Vaccines—Usually these agents consist of suspensions of live microorganisms (bacteria or viruses) or microorganisms that have had their disease-causing properties removed but their anti body-stimulating properties retained. Examples are smallpox vaccine, Salk (injected) and Sabin (oral) types of polio vaccines, and measles vaccine. 

Poliomyelitis vaccine (Salk vaccine parenteral) Inactivated poliomyelitis virus Active immunization against polio... 

Specific, for example Salk vaccine for polio prevention... 

The National Foundation, which funded the research, and the American public wanted a mass vaccination urgently. The average incidence of polio in the US in 1949-1953 was 25.7 cases per 100 000 children. The National Foundation ordered 27 million doses of the Salk vaccine for a trial, and close to one million children were vaccinated (749 236 children from Grades 1,2 and 3 were offered vaccine, and 401 974 completed the trial). 

Somehow, the status of alternative cancer therapies is akin to the role played by Australian nurse Sister Elizabeth Kenny in the treatment of polio. Her ways of assisting polio patients were more or less all that was available at the time, although often vilified, until the Salk and Sabin vaccines appeared on the scene. (With the qualifier that most new polio cases are now said to be caused by the vaccine itself.) Thus, we await the magic bullet for cancer, which may be unsuspected, but whose discovery may be fortuitous, as with penicillin and other antibiotics. No one would have anticipated that there could be such destroyers of infection as penicillin, though their existence and use were apparently known in native folklore medicine. Such may be the course for a cancer cure, that is, some native plant remedy may already be in existence, only awaiting discovery by modem medicine. Combining serendipity and purpose, someone might come up with an effective, universal vaccine. 

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