History of Vaccines Blog

May 8, 2010

In the not-so-distant past, smallpox was a scourge of mankind. It spread wildly through vulnerable populations, killing up to 30% of those it infected; those who survived were left scarred, some seriously disfigured or blind.

Smallpox ravaged the world’s population essentially unchecked for more than 3,000 years, sickening Egyptian pharaohs, British royalty, American presidents, and millions in between. But in the 1970s, the disease was nearing the end of its reign. Thanks to massive vaccination and surveillance efforts, smallpox became the first disease to be eradicated from the world. Today, we celebrate 30 years since the people of the world declared themselves free of its grasp.

The last stand

The final case of naturally occurring smallpox took place in Somalia in October of 1977, in a cook named Ali Maow Maalin. Personnel from the global eradication program immediately began efforts to find every individual Maalin had been in contact with, doing house-by-house searches and vaccinating anyone entering or leaving his town. By December 29, 1977, they completed a national search, and Maalin’s case proved to be the last. He survived.

Posted in: General, Interviews, Smallpox

May 6, 2010

In the United States, the Advisory Committee on Immunization Practices (ACIP) issues written recommendations regarding scheduling and dosing of vaccinations for both children and adults. ACIP members are selected by the Secretary of the Department of Health and Human Services to provide advice on controlling vaccine-preventable diseases; the committee is the only federal unit to make these recommendations.

ACIP issues new and updated recommendations when the status of a given disease changes, or when new data suggests that a vaccine dosage or schedule should be changed. Recently, in response to rabies surveillance data, clinical studies, experimental work and other factors, the Committee issued new recommendations for prophylactic rabies vaccination after possible exposure to the virus.

Rabies is nearly always fatal after symptoms begin to appear. However, if an exposed individual is treated promptly (with proper wound care and the administration of rabies immune globulin and rabies vaccine), the disease can usually be prevented. The previous ACIP recommendations were for five doses of rabies vaccine following exposure; now, the ACIP has reduced the dosage schedule, recommending only four doses of the vaccine for exposed individuals without prior protection against the disease. The details of ACIP’s updated recommendations are available as part of the March 19, 2010 Morbidity and Mortality Weekly Report.

Posted in: General, Rabies

May 3, 2010

Although Escherichia coli (E. coli) commonly colonizes the human digestive tract and most of its infections are benign, some strains of the bacteria can be quite dangerous. A major subgroup of E. coli, called “extraintestinal pathogenic E. coli” (ExPEC) includes strains that are responsible for more than 80% of urinary tract infections, and are the second-leading cause of neonatal meningitis and sepsis cases (blood poisoning). Urinary tract infections are associated with high health care costs, and sepsis with high infant mortality rates; in addition, the ExPEC strains have shown increasing resistance to antibiotics. In light of these issues, the development of an effective vaccine has become an important priority in combating ExPEC strains.

Now, researchers have used “reverse vaccinology” techniques to identify specific proteins in a particular ExPEC strain–proteins that could possibly provoke an immune response and be used to create a vaccine.

A reverse vaccinology approach consists of examining a pathogen’s genome to find genes with attributes that could make good targets for vaccines. The researchers in this E. coli study examined the genome sequence of ExPEC IHE3034, an E. coli strain isolated from a case of neonatal meningitis.

Posted in: General, Vaccine Research

April 29, 2010

Please visit the set of historical photographs on smallpox vaccination on The College of Physicians of Philadelphia’s Flickr page. The College’s Exhibits Manager took these photographs from a set of lantern slides in our Historical Medical Library.

It seems likely that these lantern slides were used in a presentation about smallpox vaccination and the anti-vaccination movement that was active in the early 1900s. Many of the College’s Fellows, including William H. Welch, actively countered anti-vaccination arguments with publications, letters, and public talks. In fact, College Fellow Sir William Osler, MD, often called the “father of modern medicine,” wrote this:

“Here I would like to say a word or two upon one of the most terrible of all acute infections, the one of which we first learned the control through the work of Jenner. A great deal of literature has been distributed casting discredit upon the value of vaccination in the prevention of smallpox. I do not see how anyone who has gone through epidemics as I have, or who is familiar with the history of the subject, and who has any capacity left for clear judgment, can doubt its value. Some months ago I was twitted by the editor of the Journal of the Anti-vaccination League for “a curious silence” on this subject.  I would like to issue a Mount Carmel-like challenge to any ten unvaccinated priests of Baal. I will go into the next severe epidemic with ten selected vaccinated persons and ten selected unvaccinated persons. I should prefer to choose the latter—three members of parliament, three anti-vaccination doctors, if they could be found, and four anti-vaccination propagandists.  And I will make this promise—neither to jeer nor to jibe when they catch the disease, but to look after them as brothers, and for the four or five who are certain to die I will try to arrange the funerals with all the pomp and ceremony of an anti-vaccination demonstration.” —Sir William Osler, Man’s Redemption of Man, 1910

Posted in: General, Historical Medical Library, Smallpox

April 26, 2010

Robert Abbe (1851-1928), a New York surgeon and Fellow of The College of Physicians of Philadelphia, was an avid collector of medical and archeological objects. Here at the College’s Historical Medical Library, we hold a number of Abbe’s items, including mementos from his friendship with Marie Curie. Of particular interest to this project is Abbe’s collection of Louis Pasteur memorabilia, much of it dating from the 1922 centenary celebrations of Pasteur’s birth.

The collection includes a scrapbook with photographs of Pasteur and his family, French postage stamps featuring Pasteur as a national hero, postcards of monuments dedicated to the scientist, and commemorative tags picturing key moments from his life. However, what stands out in the collection is a letter in Pasteur’s handwriting. The letter is intriguing both because it involves several of the 19th century’s most eminent scientific figures and because it presents something of a mystery.

Posted in: General, Historical Medical Library

April 22, 2010

The first vaccine to prevent pneumococcal disease in children was added to the U.S. immunization schedule in 2001. Before that, Streptococcus pneumonia bacteria caused about 17,000 cases of bacteremia (blood infections), 700 cases of meningitis, and 71,000 cases of bacterial pneumonia each year. The bacteria can also cause middle ear infections (otitis media).

The pneumococcal vaccine for children is made by Pfizer and is called Prevnar. It’s given in four doses, at two months, four months, six months, and 12-15 months old. The vaccine is more than 90% effective against invasive pneumococcal disease, and the version used until early 2010 protected against seven strains of Streptococcus pneumonia, reducing the incidence of disease caused by them by 99% as of 2007.

In February of this year, the Food and Drug Administration (FDA) licensed an updated version of the pneumococcal vaccine for children. This vaccine, Prevnar 13, protects against an additional six strains of the bacteria, and will replace the previous vaccine (Prevnar 7) in the immunization schedule, being given in four doses.

Posted in: General, Pneumococcal disease, Vaccine Research

April 19, 2010

A major difficulty with large vaccination campaigns is storage and transport of vaccine material. Most vaccines must be stored at low temperatures and require refrigeration, which isn’t always available in remote villages or over long distances of travel.

A key element of the successful campaign to eradicate smallpox was the availability of a freeze-dried vaccine. The vaccine could remain stable at relatively high temperatures, long enough to be administered in remote areas. Unfortunately, similar vaccines are not currently available for all diseases. Many vaccines still require refrigeration and have a relatively short shelf-life, and the countries that are typically in need of large-scale vaccination efforts are also the ones lacking a ready infrastructure to support such programs.

Looking to the future of vaccine development, however, researchers at the Jenner Institute of the University of Oxford recently demonstrated that it may be possible to store vaccine materials for long periods of time within sugar-stabilized membranes. Starting with a small filter-like membrane, the researchers coated it with an ultrathin layer of sugar glass, with the viral particles trapped inside it. In this form, the viruses the researchers used in their study could be stored at temperatures of up to 113°F for six months without losing their ability to provoke an immune response. By comparison, when maintained in liquid storage at 113°F for just one week, one of the two viruses tested was essentially destroyed.

Posted in: General, Vaccine Research

April 14, 2010

On April 13, The New York Times reported on promising results in global efforts to eradicate polio. Eliminated from endemic spread in the Americas in 1991, polio persists in other areas, particularly in India and Nigeria.

The World Health Organization reports that recorded polio cases are down 75% this year from the same period a year ago. Muslim leaders in Nigeria have begun to support vaccination campaigns, a sharp reversal from earlier claims that vaccination programs had secret aims of sterilizing the population or spreading HIV. And vaccination efforts have focused on remote regions in India, where polio vaccination coverage had been poor.

The Times quoted D.A. Henderson, MD, former director of the World Health Organization’s Smallpox Eradication Programme, on the possibility of polio eradication. Henderson, whom we interviewed a short time ago,  seemed encouraged by the new figures, but also called attention to the dangers of polio infection from vaccine virus types. (In 1 in every 2.5 million oral polio vaccine recipients, vaccine-derived poliovirus can mutate to a virulent form. And, in areas with low vaccination coverage, circulating vaccine-derived polio viruses from OPV have led to polio outbreaks and even deaths. See a WHO information sheet for more on this topic.)

Posted in: General, Polio

April 12, 2010

An online project from The College of Physicians of Philadelphia

The History of Vaccines is an informational, educational website being developed by The College of Physicians of Philadelphia, the oldest medical association in the United States. A group of prominent Philadelphia physicians, including Declaration of Independence signer Benjamin Rush, established the College in 1787 “to advance the science of medicine and to thereby lessen human misery.”

Today, the College’s mission is to advance the cause of health, while upholding the ideals and heritage of medicine. All aspects of the College—its physician Fellows, its Historical Medical Library, and the world-renowned Mütter Museum—serve this mission.

The College is creating The History of Vaccines to provide a living, changing chronicle of the compelling history of vaccination, from pre-Jennerian variolation practices, to the defeat of polio in the Western Hemisphere, to cutting-edge approaches to vaccination for cancer, atherosclerosis, and addiction. This site will increase public knowledge and understanding of the ways in which vaccines work, how they have been developed, and the role they play in the improvement of human health.

For more information about the project, see About.

Posted in: General

March 31, 2010

In January of this year, staff from the History of Vaccines project traveled to Baltimore along with other College of Physicians staffers to interview D.A. Henderson, MD, who directed a worldwide campaign for the eradication of smallpox—the only disease ever to be wiped out.

The campaign that eventually led to the eradication of smallpox included massive surveillance efforts to monitor disease outbreaks, “ring vaccination” (protecting those who might have been exposed to a smallpox patient), and unprecedented communication and cooperation with local populations worldwide. Dr. Henderson recently documented these efforts in his book, Smallpox: The Death of a Disease.

Posted in: Smallpox, Interviews