History of Vaccines Blog

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

March 23, 2010

Were you a polio pioneer, or are you related to someone who was? We’re looking for people who participated in the groundbreaking trial for Jonas Salk’s killed-virus polio vaccine in 1954.

We’d love to talk with you about your experience. We’re also hoping to get photograph of a Polio Pioneer card, a card given to children for participating in the first national tests of a trial polio vaccine conducted during 1954. (For reference, see a photograph of a Polio Pioneer card on the Smithsonian National Museum of American History’s excellent web exhibit on the history of polio vaccine development.) Email us at to let us know about your experiences as a Polio Pioneer.

Posted in: Polio

March 19, 2010

The Historical Medical Library at The College of Physicians is full of fascinating items, and we’ve run across many of them while developing the History of Vaccines website. One such item is a pamphlet written by Benjamin Franklin and an English doctor, outlining American and English experiences with inoculation against smallpox. This process, also called variolation, involved transferring some matter from a smallpox sore on a person with a mild case of the disease into a cut or scratch on the body of a healthy person. The usually mild local reaction would most often protect the inoculated person from contracting smallpox.

As you may have learned from our smallpox timeline, Franklin lost his four-year-old son to smallpox in 1736. He became an advocate of inoculation, arguing that although it was not without risk, it was far safer than natural infection. In 1759, Franklin asked a friend, London physician William Heberden, to write a pamphlet outlining the process of inoculation, so that anyone could learn how to perform the operation. Franklin then wrote an introduction for the pamphlet, stating that Heberden paid for printing “a very large impression” of the pamphlet to be distributed for free in America. A copy of the pamphlet “Some Account Of the Success of Inoculation for the Small-Pox in England and America together with Plain Instructions, By which any Person may be enabled to perform the Operation, and conduct the Patient through the Distemper,” is in the Historical Medical Library.

Posted in: Smallpox, Historical Medical Library

March 15, 2010

In late February 2009, the Advisory Committee for Immunization Policies (ACIP) of the Centers for Disease Control and Prevention (CDC) expanded its guidelines on who should take the seasonal influenza vaccination in the 2010-2011 flu season. ACIP advises, and CDC will likely recommend, that all adults should receive the seasonal flu vaccine. In previous years, healthy adults ages 19-49 with no underlying risk factors were not recommended to receive the vaccine.

Now all people 6 months and older are recommended to be vaccinated for seasonal influenza.

Posted in: Influenza