all vaccines stories

Inhaled tuberculosis vaccine may be more effective than injected vaccine

404132862 — Wed, 12 Mar 2008 13:58:18 -0400

A novel aerosol version of the most common tuberculosis (TB) vaccine, administered directly to the lungs as an oral mist, offers significantly better protection against the disease in experimental animals than a comparable dose of the traditional injected vaccine, researchers report this week (March 12) in the Proceedings of the National Academy of Sciences (PNAS).

Pursuing a cholera vaccine

50443248 — Tue, 15 May 2007 09:47:03 -0400

The reports from Dhaka are hopeful. It is 2005, and Dr. Firdausi Qadri and colleagues at the International Center for Diarrheal Disease Research, Bangladesh, are testing a new cholera vaccine on children. In their study, a single dose of live, crippled bacteria goes down easily in a fizzy drink. Within days, most of the children are showing exactly the kind of robust immune response that should enable them to fend off an attack from the deadly pathogen, with no notable side effects.

The study follows a similar success immunizing adults in the same city. The stage is now set for a large-scale trial to test the vaccine, known as Peru-15, to prevent the seasonal flare-ups of life-threatening diarrhea that dog the poor in Bangladesh and other regions of the developing world.

Spray-dry vaccine for TB developed

Wed, 11 Jul 2007 10:47:14 -0400

Bioengineers and public health researchers have developed a novel spray-drying method for preserving and delivering the most common tuberculosis (TB) vaccine. The low-cost and scalable technique offers several potential advantages over conventional freezing procedures, such as greater stability at room temperature and use in needle-free delivery. The spray-drying process could one day provide a better approach for vaccination against TB and help prevent the related spread of HIV/AIDS in the developing world.

Nicotine vaccine to be tested at Massachusetts General Hospital

70652986 — Mon, 26 Mar 2007 06:27:57 -0400

A novel approach to helping smokers kick the habit - a vaccine - will be tested at Massachusetts General Hospital (MGH). The nicotine vaccine NicVax is designed to keep nicotine from reaching the brain where it produces its rewarding effects. Earlier studies of the vaccine, which has not yet received FDA approval, have indicated that it is safe and may be effective.

"We currently have several proven ways to help smokers quit - including nicotine patches and gum and the antidepressant bupropion - but if someone using these medications slips and smokes a cigarette, he or she experiences rewarding sensations from smoking," says Nancy Rigotti, MD, director of the MGH Tobacco Research and Treatment Center, who will lead the study at the hospital. "Since this vaccine keeps nicotine out of the brain, smoking no longer has any pleasurable effects, and the smoker should find it easier to quit."

Although the immune system does not normally respond to nicotine, NicVax - manufactured by Nabi Biopharmaceuticals, which is sponsoring the current trial - is designed to elicit the production of nicotine antibodies. If someone smokes after being immunized, the antibodies bind with nicotine molecules in the bloodstream and prevent them from entering the brain where nicotine receptors are located.

The MGH is one of 10 centers across the country participating in the current study and is the only location in the Northeast.

Study: Hope alive for AIDS vaccine

Fri, 13 Jul 2007 10:35:21 -0400

Researchers from the Dana-Farber Cancer Institute and Harvard Medical School (HMS) have prompted human immune cells to attack HIV protein fragments, showing that the long-sought vaccine to protect against AIDS is still a possibility.

Researchers using advanced data-analysis programs identified five protein fragments from HIV - the virus that causes AIDS - that promote a strong immune response from the cells of people who have never been exposed to the HIV virus before.

That means, researchers said, that creation of a vaccine to protect unexposed individuals from infection with HIV appears possible. Researchers conducted their study using fragments from HIV-1, the more virulent of the two strains known to cause AIDS.

For 20 years, scientists have fought the disease and sought ways to prevent the AIDS virus from devastating patients' immune systems. It is the virus's destruction of the body's immune response that opens patients to a variety of opportunistic infections that run rampant and, ultimately, cause death.

Researchers had thought that human immune system cells don't fully recognize the HIV-1 virus and so can't eliminate it from the body after infection. The new study shows that isn't the case and suggests shifting efforts toward creating a vaccine aimed at uninfected individuals.

The study, published in the online journal Medical Immunology, was led by Dana-Farber's Pedro Reche, an instructor in medicine at HMS, and by Derin Keskin, a research fellow in medicine at HMS.

"It has been unknown for 20 years why HIV-1 becomes persistent and isn't cleared from the bodies of AIDS patients," says Medical Immunology's editor, Kendall Smith, chief of the Division of Immunology at Weill Medical College at Cornell University. "This study suggests that in HIV-positive people, the immune system cells that respond to HIV-1 are either deleted or have lost the ability to recognize and home in on major parts of the virus."

If these findings hold true in follow-up studies, they suggest that exposing healthy people to HIV-1 proteins might train their immune system to attack the virus and prevent them from developing AIDS if exposed to HIV-1 in the future, Reche said.

Senior author of the study is Professor of Medicine Ellis Reinherz, of Dana-Farber and Harvard Medical School. Other co-authors, all of Dana-Farber and Harvard Medical School, are Rebecca Hussey, research associate in pathology; Petronela Ancuta, research fellow in pathology; and Professor of Neurology Dana Gabuzda.

Study offers new hope for preventive vaccine for AIDS

70652986 — Mon, 26 Mar 2007 06:27:37 -0400

New research by Dana-Farber Cancer Institute scientists suggests that it may one day be possible to immunize healthy individuals against HIV-1, the virus that causes AIDS.

In a study published in the online journal Medical Immunology, investigators led by Dana-Farber's Pedro Reche, Ph.D., and Derin Keskin, Ph.D., upend the long-held view that human immune system cells do not fully recognize HIV-1 following infection, and thus are unable to eliminate it from the body. The researchers found that lab-grown immune system cells from uninfected individuals are able to distinguish and respond to key HIV proteins. Cells taken from infected individuals, by contrast, were much less responsive to the virus.

If these findings hold true in follow-up studies, they suggest that exposing healthy people to HIV-1 proteins might train their immune systems to attack the virus and prevent them from developing AIDS if exposed to HIV-1 in the future, Reche said.

The research was funded in part by grants from the National Institutes of Health.

Potential Alzheimer's vaccine improves learning and memory deficits in mice

70652986 — Mon, 26 Mar 2007 06:27:13 -0400

Researchers have found that a vaccine for Alzheimer's disease improves learning and memory deficits in mice.

"Our findings show promise for a potentially safer and more effective Alzheimer's vaccine in humans," says senior researcher and Harvard Medical School associate professor Cynthia Lemere. Lemere and colleagues at Brigham and Women's Hospital report combined immunological, neuropathological, and behavioral benefits of the vaccine in mice.

"Next, we plan to further refine our novel vaccine and prepare for possible human trials," she says.

The study appears in the May 3, 2006 issue of The Journal of Neuroscience.

Less than half of U.S. health care workers get flu shots

70652986 — Mon, 26 Mar 2007 06:24:12 -0400

Steffie Woolhandler, Harvard Medical School associate professor of medicine at Cambridge Health Alliance, and colleagues at the University of California Los Angeles analyzed data from the 2000 National Health Interview Survey and found that less than half of U.S. health care workers get flu shots.

From a nationally representative sample of 1,651 workers, the overall vaccination rate was only 38 percent. Rates were particularly low in workers who were health aides (e.g. nurses' aides, medical assistants or orderlies), African American, or under 50.

The low flu vaccination rate among health care workers increases their likelihood of contracting the flu and passing it to patients. Health care workers, especially those who are minority, poor, or young, need both better education and improved access to primary care in order to reduce the spread of flu. Inequalities in health care currently undermine our ability to stop flu transmission. Should an epidemic of bird flu emerge, such inequalities will hamstring efforts to contain it.

Study finds vaccines boost the economies of poor countries

70652986 — Mon, 26 Mar 2007 05:40:47 -0400

A study determined that previous measurements of the benefits of immunization have generally underestimated their economic value by focusing solely on health-related impacts such as averted illnesses, hospitalizations, deaths, disability, and medical costs. The study provides a more thorough investigation of the impacts of vaccination by looking at its effects on cognitive development, educational attainment, labor productivity, income, savings, investment, and fertility. The article is authored by David E. Bloom and David Canning of the Harvard School of Public Health, and Mark Weston of River Path Associates, a knowledge consultancy based in the UK. "Our study finds that the benefits of vaccination have been greatly underestimated. The economic impacts of immunization stem from the fact that immunization protects individuals not only against getting an illness per se, but also against the long- term effects of that illness on their physical, emotional, and cognitive development," said David E. Bloom, who is Clarence James Gamble Professor of Economics and Demography at HSPH. "When kids grow up healthier, they do better in school and, later, as adults, are more productive, earn more, and save more. Overall, we found powerful new sources of economic returns from immunization."

Vaccine may clear Alzheimer's brain plaques

70652986 — Mon, 26 Mar 2007 05:41:07 -0400

While there is still no consensus about the role of waxy amyloid plaques that fill the brains of Alzheimer's patients, many in the field believe they are a root cause of neurodegeneration and that clearing them may improve the cognitive function of patients. A major strategy has been to remove amyloid-beta by creating antibodies against it. But trials for an amyloid-beta vaccine were halted in 2003 when 6 percent of the patients developed life- threatening encephalitis. Since then, two follow-up studies provided some evidence that patients did benefit, raising hopes that a vaccine may work if side effects are limited. Another trial is under way to see if delivering amyloid-beta antibodies, rather than the peptide itself, can be effective and safer.

In the September 2005 Journal of Clinical Investigation, a team led by Howard Weiner, the Robert L. Kroc professor of neurology at Harvard Medical School and Brigham and Women's Hospital, unveiled another vaccine strategy for Alzheimer's disease that clears the build-up of amyloid plaques in a mouse model. The new strategy triggers cells of the immune system to gobble up amyloid-beta, sidestepping antibodies completely. It is delivered as a simple nasal spray, and consists of two FDA-approved drugs already in use for other conditions.

The vaccine emerged from a fortuitous discovery during an investigation of the role of the immune system in Alzheimer's. After the problems with the amyloid-beta vaccine, Weiner worked with postdoctoral fellow Dan Frenkel and Ruth Maron, assistant professor of neurology at BWH, to investigate the relationship between Alzheimer's and an overactive immune system that would produce encephalitis.

New findings about protection against pneumococcal disease

70652986 — Mon, 26 Mar 2007 06:20:00 -0400

Before the advent of the pneumococcal vaccine, known as Prevnar, S. pneumoniae caused millions of ear infections each year, half a million episodes of bacterial pneumonia, and life- threatening cases of meningitis and bacteremia. Prevnar triggers recipients' immune systems to produce "anticapsular antibodies." However, Prevnar doesn't work well in the developing world, and it is expensive and difficult to manufacture. Moreover, in several studies, use of pneumococcal conjugate vaccines caused non-vaccine strains to become more common, suggesting that Prevnar could eventually become ineffective even in the U.S.

Lipsitch and Malley first conducted epidemiologic studies in unvaccinated toddlers in the U.S., Israel, and Finland, and the incidence of invasive disease from most pneumococcal strains fell by nearly half between one and two years of age. Yet anti- capsular antibody concentrations increased only slightly.

Searching for what caused these results, Malley and Lipsitch were able to elicit long-lasting immunity to pneumococcus in mice independently of any antibodies. When the mice were exposed to live pneumococci, or to a whole-cell vaccine developed in Malley's lab, they were immune to pneumococcal colonization, regardless of their ability to make antibodies. Moreover, mice exposed to a single pneumococcal strain became immune not just to that strain and others. The immunity appeared to arise from an effect on the immune system's CD4+ T-cells.

Their findings suggest that while antibodies protect sufficiently against pneumococcal disease, they may not represent the natural mechanism of protection.

The whole-cell vaccine could protect against all pneumococcal strains, Malley says, and would be a boon for the developing world because it is inexpensive, covers all pneumococcal strains, and does not require refrigeration.

Findings recommend herpes vaccine for human trials

70652986 — Mon, 26 Mar 2007 05:36:29 -0400

Research published in the January 2005 Journal of Virology compared three different experimental vaccines for herpes simplex virus 2 (HSV-2), which causes most cases of genital herpes. Lead author Stephen Straus, senior investigator in the Medical Virology Section in the Laboratory of Clinical Infectious Diseases at the National Institute of Allergy and Infectious Diseases, tested the vaccines in two established animal models of herpes infection. A vaccine developed by Harvard researcher David Knipe, called dl5-29, outperformed the other two vaccines, one of which has already been tested in humans. Straus said that the results argue strongly for taking dl5-29 into human trials. "Based upon dl5-29's biological and immunological properties, it appears to be the most compelling new vaccine candidate for genital herpes," he said. HSV-2 infects one in five Americans, and its prevalence has reached 50 percent in some developing countries, where it also seems to be helping to fuel the spread of HIV. HSV-2 infection, though incurable, typically does not cause major health problems, but can be life-threatening in immunocompromised people and newborn babies infected by their mothers.

Images reveal how leading cause of severe childhood diarrhea enters cells

70652986 — Mon, 26 Mar 2007 06:18:51 -0400

The work illustrates how vaccine development can advance by probing the physical architecture of viruses and finding the parts needed to prime the immune system.

Rotavirus, which causes severe diarrhea and vomiting, infects most children, causes gastroenteritis that sometimes requires hospitalization, and kills about 440,000 children each year. The only licensed vaccine, RotaShield, was discontinued following reported cases of a condition causing bowel obstruction.

Research team leader Philip Dormitzer says of the outside layer of rotavirus that "its job is to get the innermost portions inside the cell."

From the outer layer project clusters of VP4 molecules, which Dormitzer's team trimmed down, crystallized, and diffracted using X-ray diffraction to determine their structures. VP4 undergoes shape changes that allow it to breach the membrane of the cell it's trying to infect.

First, when rotavirus arrives in the intestine, the VP4 molecules prime the virus to attack the cell. Then, VP4 breaks a hole in the cell membrane, letting the virus enter.

"The work is a clear example of the way in which structural studies can contribute to new good ideas about strategies for vaccines," says Senior Investigator Stephen Harrison, Ph.D.

Many Americans at high risk from flu not vaccinated

70652986 — Mon, 26 Mar 2007 05:33:51 -0400

The Centers for Disease Control and Prevention highly recommends the flu vaccine for certain high-risk groups including people with chronic illnesses, children between the ages of six and 23 months, and people aged 65 and over. A national poll conducted by the Harvard School of Public Health Project on the Public and Biological Security found in December 2003 that nearly half (47%) of people with chronic illnesses had not had a flu vaccination in the past three months. In addition, more than three-fourths (78%) of parents reported that their children ages six to 23 months had not received a flu vaccine. This was the case even though the vaccine recommendation for these young children was widely known by Americans (74%). One in 10 Americans (10%) reported that they had not gotten a flu vaccine due at least in part to shortages. About one-third of these people (3% of the public) still planned to get vaccinated in the next three months, but two-thirds (7%) do not. The study was designed and analyzed by researchers at the Harvard School of Public Health.

Dual action anthrax vaccine more effective than current vaccine in early tests

70652986 — Mon, 26 Mar 2007 05:31:35 -0400

A new vaccine prods the immune system to attack both the anthrax bacterium ( Bacillus anthracis ) and the toxins it makes. This dual action represents an improvement over the currently available vaccine, which targets only the toxins. In a test of the vaccine using mice, animals were injected first with the vaccine, then 10 days later with anthrax toxin. All the vaccinated mice survived the toxic challenge, while unvaccinated mice exposed to the toxin died within 24 hours. "It worked like a charm," said Julia Wang, Harvard Medical School assistant professor at Brigham and Women's Hospital, who led the study. "Clearly, there is a need for a better anthrax vaccine," she added. The researchers suggest that the new vaccine will also be an important tool for treating those already infected with anthrax as a so-called therapeutic vaccine.