History of Vaccines Blog


July 15, 2010  Anonymous

People in developed countries don’t tend to spend much time worrying about waterborne diseases. Modern water treatment systems have drastically improved the safety of public water supplies, and if people have even heard of parasitic diseases like Cryptosporidiosis (commonly called “crypto”) or Giardiasis, they tend to think of them merely as an unpleasant bout of diarrhea–uncomfortable and inconvenient, but nothing serious. Parasitic diseases like Crypto and Giardiasis, however, as well as bacterial illnesses like Legionnaires’ disease, can cause severe infections that lead to hospitalization and death, even in developed nations. Recently, researchers from the Centers for Disease Control and Prevention analyzed the annual cost of hospitalizations for cases of Legionnaires’, Crypto and Giardiasis in the United States. Using insurance claim data from 2004-2007, the researchers determined that cases of hospitalization from the three diseases may cost more than half a billion dollars annually–including both costs paid by insurance companies and costs paid out-of-pocket by patients. Among the three, Legionnaires’ was found to have the highest annual financial toll due to hospitalization, with the total cost estimated to be between $101 and $321 million. A single inpatient hospitalization for a case of Legionnaries’ averaged more than $34,000. Read More...

Posted in: General

July 12, 2010  Anonymous

Researchers have examined many possible approaches for vaccines against malaria, a parasitic illness spread by mosquitoes that affects hundreds of millions of people each year. One of the most promising approaches thus far has been a subunit vaccine: a vaccine candidate using this approach, RTS,S, is in late-stage clinical trials. Researchers in Queensland, Australia have begun testing another approach, however: a vaccine that combines killed parasites with an adjuvant to boost immune response. The resulting vaccine was tested in mice, and was shown to provide long-lasting, cross-strain protection against malaria. The group focused on developing a vaccine with the lowest possible dose of killed parasite that would still elicit a protective immune response. Their test vaccine induced a broadly reactive T cell response of the type usually generated by live, attenuated vaccines–yet with a safety profile more in line with a killed vaccine. Read More...

Posted in: General, Vaccine Research, Malaria

July 8, 2010  Anonymous

HIV is a challenging target for vaccine researchers for many reasons, not the least of which is its lack of stability. The surface proteins of the virus frequently change, keeping the immune system from recognizing it–and keeping researchers from selecting a surface protein as a stable target for a vaccine. At least one area on the surface of the virus, however, seems to remain fairly stable across all variants of HIV: a site located on the surface spikes the virus uses to bind to and infect immune cells. Now, two teams of researchers have found antibodies that attach to this site, preventing the virus from binding to immune cells, and have highlighted ways this discovery may lead to new advances in HIV vaccine designs. The antibodies are found in the blood serum of many individuals infected with HIV. The researchers selected HIV-1 isolates encompassing all of the major circulating subtypes of the virus, and showed that these antibodies could bind to–and neutralize–more than 90% of them. That broad ability to neutralize so many variants of the virus is because of the stability of the binding site, which remains the same among nearly all strains. Therefore, a vaccine that could “train” the human immune system to generate similar antibodies could provide protection against the majority of circulating HIV variants. Read More...

Posted in: General, HIV, Vaccine Research

July 1, 2010  Anonymous

A post on the History of Vaccines blog earlier this month mentioned an outbreak of whooping cough in California, noting that at the time, four infants had already died from the disease. The death count has now reached five, all children less than three months of age, and the total number of confirmed cases reached 910 as of June 15th. The director of the California Department of Public Health declared in a statement that the outbreak is now an epidemic. The most recent major outbreak of whooping cough was in 2005, when 3,182 cases were recorded in California. This year’s epidemic is on pace to surpass the number of cases from 2005. An outbreak has also been reported in Ohio, and Oregon public health officials have reportedly noted an unusually high number of cases there as well. Whooping cough can be prevented by vaccination, but the first dose of the vaccine is not given until two months of age. Prior to that infants are highly susceptible to the disease, which is often spread by adults. A booster vaccine against whooping cough is available for adults as part of the Tdap (tetanus, diphtheria, pertussis) immunization, which can be substituted for one tetanus or Td vaccination between the ages of 19 and 64. The Advisory Committee on Immunization Practices (ACIP) recommends Tdap vaccination for adults who have contact with infants younger than 12 years of age. Read More...

Posted in: General, Pertussis (whooping cough)

June 28, 2010  Anonymous

Marburg virus, like its fellow filovirus Ebola, causes hemorrhagic fever and high death rates among humans. Also like Ebola, the virus is considered a potential bioweapon and has no known treatment or cure post-infection. Developing a vaccine capable of providing protection against diseases like Ebola and Marburg after exposure has become a priority in light of known laboratory accidents and hypothetical first-responder scenarios. In 2009, a Hamburg scientist working with Ebola-Zaire accidentally pricked herself with a contaminated needle, setting off panicked global attempts by researchers to help her. Eventually the woman, a virologist from the Bernard Nocht Institute for Tropical Medicine, was given an experimental Ebola vaccine that had shown promise in preventing infection in monkeys when given post-exposure. She never developed the disease, although it’s not known whether the vaccine protected her from it. Prior to the Hamburg case, the previous known exposure was in 2004, in a U.S. Army researcher at Fort Detrick, Maryland. These cases, in addition to hypothetical scenarios in which first responders may be exposed to filoviruses–coupled with the fact that no known treatment exists–have prompted efforts to further develop and test post-exposure vaccines. Read More...

Posted in: General, Vaccine Research

June 26, 2010  Anonymous

Smallpox, HIV, influenza: the names of these pathogens usually induce fear. Smallpox, although it has been eradicated for 30 years, killed millions in its time; HIV, a relative newcomer to the human race that appeared just a few years after smallpox was eradicated, infects 7,400 people each day. Influenza presents its own unique challenges with its tendency toward frequent genetic change, requiring new seasonal flu vaccines each year and sometimes surprising us with unexpected new strains. Artist Luke Jerram examines these and other pathogens in Infectious Beauty, an exhibit of “glass microbiology” at the Heller Gallery in New York.  In creating these pieces, according to his website, Jerram explores “the tension between the artworks’ beauty, what they represent and their impact on humanity. ” Jerram consulted with virologists before designing the sculptures, which were then created by professional glassblowers. His motivation stemmed partly from dissatisfaction with the way viruses and bacteria are typically portrayed: in color, even though the electron microscope photos usually used to capture them are black and white. Jerram, who is partially colorblind, considered how artificial coloring of these pathogens affected viewers’ understanding of them. Read More...

Posted in: General, HIV, Influenza, Smallpox

June 24, 2010  Anonymous

Though not well known in the United States, Rift Valley fever (RVF) is a dangerous viral disease that is a major cause for concern in Africa. RVF primarily affects animals and can infect several species, including cattle, sheep, goats and camels. Protecting animals from the virus is extremely important in farming, as it has a high death rate for some animals of a particular age (up to 90% for lambs) and can cause a near-100% abortion rate among pregnant ewes. These losses can be devastating for those who raise livestock. Rift Valley fever is also a concern, however, because it can sometimes infect humans. This typically occurs through contact with infected animals, but the virus can also be spread by the bite of infected mosquitoes or blood-feeding flies. Some evidence suggests that humans can even be infected by drinking unpasteurized or uncooked milk from infected animals. Typically a human infection with RVF is mild and passes without treatment, but there are three more serious forms of the disease: one that leads to retinal lesions (and possible blindness); one that leads to meningoencephalitis and leaves the victim vulnerable to residual neurological problems; and one that leads to haemorrhagic fever, with a death rate as high as 50%. Prior to 1997 the disease had been limited to Sub-Saharan regions, but outbreaks have since occurred in Saudi Arabia, Mauritania, Egypt and Yemen, and outbreaks in Kenya, Somalia and Tanzania from 2006-2007 led to human deaths, raising concern that the virus could continue to spread. The United States federal government has also classified RVF as a potential biowarfare threat. Read More...

Posted in: General, Vaccine Research

June 21, 2010  Anonymous

International Health Regulations allow countries at risk for yellow fever transmission to request certificates of vaccination from foreign travelers. If a visitor is coming from a country considered “high risk” for the disease, they must present a yellow fever certificate approved by the World Health Organization–sometimes at the port of entry, and sometimes before they can even obtain a travel visa. These policies have no doubt prevented yellow fever transmission, but vaccine shortages in Uganda combined with yellow fever health regulations have led to headaches for some World Cup fans. Uganda’s South African mission, where visas are issued for Ugandans traveling to the World Cup, can’t issue those visas without yellow fever certificates–and many would-be travelers don’t have the certificates, because they haven’t been able to get the vaccine. CNN’s Samson Ntale reported on June 17 that the large number of travelers headed for South Africa during the World Cup exacerbated the Ugandan vaccine shortage. Ntale reported that more yellow fever vaccine has been ordered, but that in the meantime, many Ugandans have been first traveling to other countries to get their vaccinations and certificates, including Kenya and Tanzania. Read More...

Posted in: General, Yellow Fever

June 17, 2010  Anonymous

It can be difficult to explain to a two-year-old that the scary-looking needle headed for her arm will actually help keep her healthy. To a young child, “I’m giving you a vaccine to protect you from the measles” often sounds more like, “I’m going to jab you with a pointy object.” Childhood vaccinations come with their share of pain and crying. In a review published in Archives of Disease in Childhood (A BMJ journal), Denise Harrison and co-authors report that feeding sugar solutions to children during or after vaccinations can reduce the incidence and duration of crying, as well as pain. Previous research had established that sugar solutions could reduce pain associated with vaccination in newborn children–a key finding, since the first dose of Hepatitis B vaccine is recommended before newborns are discharged from the hospital. However, beyond one month of age, the evidence was not conclusive. Harrison and her colleagues set out to compare the effects of sugar solutions to that of water, as well as no treatment, in children 1-12 months old–a period of time during which it’s recommended they receive Hepatitis B, rotavirus, DTaP, Hib, pneumococcal, and polio vaccines. Read More...

Posted in: General, Vaccine Research

June 14, 2010  Anonymous

The Historical Medical Library here at The College of Physicians of Philadelphia holds seven floors of stacks of books, journals, and archives. The scale of the library, and its testament to human illness, can be overwhelming. Our recent research on tuberculosis provides an example: standing in the stacks, surrounded by row upon row of books about TB, is a grim experience. But though our library gives the impression that TB is an historical artifact, it’s most certainly not. It continues to take an enormous global toll: there are 9.4 million new infections a year, and there were 1.3 million deaths from TB in 2008 alone. One of these recent trips into the stacks led us to the Final Report of the International Tuberculosis Campaign (1951), an optimistic portrait of the promises of an early immunization campaign. The book offers comprehensive statistics of the massive tuberculosis campaign undertaken in 23 countries in the late 1940s and early 1950s. The project initially began as a Scandinavian Red Cross effort in Europe in the aftermath of World War II. Tuberculosis rates had soared in the disruption and privation the war created. In Poland, tuberculosis rates among children had quadrupled. As Niels Brimnes writes, the president of the Danish Red Cross announced on the radio in 1948, “The spirit of the Nordic Vikings has been part of this campaign as in the old days. Earlier we went out sword in hand to conquer and fight each other. Today we go out together with the needles as our only weapon to fight the scourge of the Second World War: tuberculosis” (Niels Brimnes, “Vikings against Tuberculosis: The International Tuberculosis Campaign in India”). Read More...

Posted in: Historical Medical Library, Tuberculosis