vaccines
The benefit of some cancer vaccines may be boosted by treating patients with an antibody that blocks a key protein on immune system T cells, according to a small, preliminary study led by researchers at Dana-Farber Cancer Institute and Brigham and Women's Hospital. The study tested the effect of a single injection of the antibody MDX-CTLA4 in nine patients who had previously been treated with cancer vaccines for either metastatic melanoma or metastatic ovarian cancer. The result, in every patient who had received a particular kind of vaccine, was widespread death of cancer cells and an increase in the number of immune system cells within the tumors ? evidence of a potent immune system attack.
Once a year, Ronald Schultz checks the antibody levels in his dogs' blood. Why? He says for proof that most annual vaccines are unnecessary. Schultz, professor and chair of pathobiological sciences at the University of Wisconsin-Madison School of Veterinary Medicine, has been studying the effectiveness of canine vaccines since the 1970s; he's learned that immunity can last as long as a dog's lifetime, which suggests that our "best friends" are being over-vaccinated. Based on his findings, a community of canine vaccine experts has developed new veterinary recommendations that could eliminate a dog's need for annual shots. The guidelines appear in the March/April issue of Trends, the journal of the American Animal Hospital Association (AAHA).
In a new study in mice, a modified form of an innocuous chimpanzee virus has shown marked potency as a protective vaccine against HIV, itself believed to have crossed into the human population from chimpanzees sometime in the 1930s. The study, led by researchers at The Wistar Institute, appears in the February issue of the Journal of Immunology. "Our results show this new vaccine is capable of inducing the kind of powerful immune response that we and others believe will be critical for controlling HIV infection," says Hildegund C.J. Ertl, M.D., professor and immunology program leader at The Wistar Institute, and senior author on the new study.
HHS Secretary Tommy G. Thompson today announced the award of two contracts totaling up to $20 million in first-year funding to develop safer smallpox vaccines. The three-year contracts were awarded to Bavarian Nordic A/S of Copenhagen, Denmark, and Acambis Inc. of Cambridge, Mass. The National Institute of Allergy and Infectious Diseases (NIAID) will administer the contracts.
An ongoing national shortage of a vaccine that prevents meningitis and pneumonia in children has left doctors scrambling to provide even the minimum number of shots, and has exposed gaps in the nation's "patchwork" vaccine system, the first-ever in-depth study of the problem finds.
In a new study in mice, a modified form of an innocuous chimpanzee virus has shown marked potency as a protective vaccine against HIV, itself believed to have crossed into the human population from chimpanzees sometime in the 1930s. The study, led by researchers at The Wistar Institute, appears in the February issue of the Journal of Immunology. "Our results show this new vaccine is capable of inducing the kind of powerful immune response that we and others believe will be critical for controlling HIV infection," says Hildegund C.J. Ertl, M.D., professor and immunology program leader at The Wistar Institute, and senior author on the new study.
By solving a long-standing puzzle about how the influenza virus assembles its genetic contents into infectious particles that enable the virus to spread from cell to cell, scientists have opened a new gateway to a better understanding of one of the world's most virulent diseases. This insight into the genetic workings that underpin infection by flu, reported in the Proceedings of the National Academy of Sciences, provides not only a better basic understanding of how flu and other viruses work, but holds significant promise for new and improved vaccines and drugs to combat the disease by exposing the genetic trick it uses to form virus particles.
Several additional cancer centers in the United States and Canada are enrolling patients in an innovative clinical trial evaluating the use of a therapeutic cancer vaccine in patients with first-line metastatic colorectal cancer. In addition, a second trial using the vaccine earlier in the course of disease is now under way in centers across Canada, according to Aventis Pasteur Limited of Toronto, Canada, the study sponsor.
Healthy adults ages 18 to 29 are needed for a research study comparing the safety and effectiveness of two different vaccines for the prevention of the smallpox disease. The study will compare three dose levels of a new vaccine with the current, approved smallpox vaccine that was provided to all U.S. residents during the period of routine smallpox vaccination. The effectiveness of these trial vaccinations will be measured by observing whether or not there is a skin reaction, such as a blister, at the sight of the vaccination. A skin reaction is a typical response to smallpox vaccination. The response also will be measured by examining the size of the skin reaction and the time it takes for the blister to heal. Participants may become immune to smallpox, which would reduce or prevent infection with smallpox.
A report of an individual infected with a second strain of HIV despite effective drug treatment following the first infection has researchers concerned. "For the first time, we've shown it is possible for an individual to become infected with two closely related strains of HIV," says Bruce D. Walker, M.D., a researcher at Massachusetts General Hospital and Harvard Medical School. The findings underscore the challenges vaccine developers face in creating a broadly effective vaccine against HIV. The first HIV vaccines may not prevent infection altogether, but rather may prevent HIV from causing disease by limiting the virus' ability to reproduce, explains Dr. Walker. This case shows that a hypothetical vaccine against one strain of HIV may not necessarily protect the vaccinee against other, closely related strains.
A person's state of mind may influence the body's response to a vaccine against meningitis C, suggests new research. The findings support previous research showing a link between psychological factors and antibody response to vaccines. The results of a broad survey revealed that a high level of perceived life stress, but not actual stress, was associated with low antibody levels. A low level of psychological well being - feeling anxious or under strain, for example - was also linked to low antibody levels.
Researchers have discovered that a molecule best known for its anti-microbial properties also has the ability to activate key cells in the immune response. This newly discovered function suggests the molecule, a peptide called ?-defensin 2, may be useful in the development of more effective cancer vaccines.
Researchers in Northern California are conducting a clinical trial that will test whether diluted doses of the smallpox vaccine produce adequate immunity in adults who have previously been vaccinated. The results of the federally funded study, for which volunteers are now being sought, will help shape U.S. policy on how the vaccine would be given in the event of a smallpox outbreak.
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Smallpox immunity lasts longer than thought
FROM THE TRENCHES: A consortium of scientists announced that it has deciphered the genetic code of the parasite that causes the deadliest form of Malaria, an illness that kills more than a million people a year in developing nations.
