Posts Tagged
‘vaccine’
by ilene - July 11th, 2010 12:58 pm
By Alice Park, courtesy of TIME
An electron micrograph scan of HIV-1 budding from a cultured lymphocyte.
ScienceVU / CDC / Visuals Unlimited / Corbis
In the continuing search for the Achilles heel of HIV, researchers may finally be enjoying some success.
This week, government researchers at the Vaccine Research Center of the National Institute of Allergy and Infectious Diseases (NIAID) reported the discovery of two naturally occurring antibodies that may block HIV. Describing their work in two separate papers in the journal Science, AIDS experts said that in lab experiments, the antibodies had successfully prevented more than 90% of circulating HIV strains from infecting human cells.
This is not the first discovery of so-called broadly neutralizing antibodies. Last September, scientists at Scripps Research Institute and the International AIDS Vaccine Initiative (IAVI) identified two other antibodies that prevent against infection from 80% of existing HIV strains — the most potent known antibodies at the time. The findings were also published inScience.
The two sets of antibodies target different regions of the virus-cell interface — together they could help scientists develop a formidable vaccine against AIDS, says Dr. Anthony Fauci, director of NIAID. "The strategy is going to be to put the best antibodies together, and you are going to have a whopper against HIV," he says.
Antibodies are the first-line soldiers of the immune system. Produced by specialized cells in the body that recognize incoming viruses and bacteria, antibodies act as molecular barricades, latching onto and blocking pathogens from infecting healthy cells. This antibody response is the core of all vaccine-based disease prevention.
But HIV is notoriously changeable. The virus continuously alters the makeup of the proteins on its surface, eluding attack from antibodies created by the immune system and from the relatively weak vaccines that have been developed against the virus so far.
The two new antibodies described in…
Tags: AIDs, antibodies, HIV antibodies, science, vaccine
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by ilene - March 2nd, 2010 12:07 am
By Eben Harrell, courtesy of TIME
In December, the Centers for Disease Control and Prevention (CDC) launched a public health campaign in the U.S. encouraging vulnerable patients — particularly the elderly — to "protect yourself and the ones you love against flu: GET VACCINATED!" At least one flu-vaccine researcher disagreed with the message: Tom Jefferson, an epidemiologist with the prestigious Cochrane Collaboration, which has headquarters in Britain.
Jefferson and colleagues have published several systematic reviews of existing studies on the efficacy of influenza vaccines. Weighing the data, they conclude that there is insufficient evidence to indicate that flu vaccines reduce infection rates or mortality, even in the elderly. Jefferson, a former British army doctor now based in Rome, spoke with TIME about his quest to spur further research into flu vaccines.
On Feb. 16, the Cochrane Library published your updated review of all major studies on the efficacy of flu vaccines for the elderly, some of the results of which you believe to be preposterous. Can you explain?
We looked at studies on vaccines in the elderly and in health care workers who work with the elderly, and we found an implausible sequence of results. We have studies that claim up to 90% effectiveness against death from all causes [in inoculated patients compared with the nonvaccinated]. If you were to believe that evidence, you would believe that flu vaccine is effective against death not only from influenza, but also from heart attack, stroke, hypothermia, accidents and all other common causes of death among the elderly. That is quite clearly nonsense.
This is not to say that these and other studies, taken together, suggest that vaccines don’t work for the elderly. The answer is a question mark. We don’t know what protection, if any, vaccines offer. I don’t think that’s a bad thing. Uncertainty is the motor of science. We need large studies to find out.
Why do you think such studies have not been done?
I don’t know. We’ve known for years that we needed proof one way or the other, and governments have not taken any notice of this. It’s an extraordinary situation.
One argument I’ve heard is that it would be unethical to compare vaccines against a placebo because you would be withholding crucial treatment from patients. Do you agree?
No. We don’t know these vaccines work, so you can’t…
Tags: CDC, Cochrane, flu, Tom Jefferson, vaccine
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by ilene - December 11th, 2009 11:35 pm
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By Alice Park, courtesy of
TIME Since early November, cases of H1N1 have continued to decline nationwide, and scientists keeping track of the numbers say that as pandemics go, 2009 H1N1 may turn out to be a mild one — at least for the time being.
The question now on health officials’ minds is: Will there be a second wave of cases in the new year? The answer depends on whom you ask. "We took an informal poll of about a dozen of some of the world’s leading experts in influenza," Dr. Thomas Frieden, director of the Centers for Disease Control and Prevention (CDC), told reporters recently. "About half of them said, Yes, we think it’s likely that we’ll have another surge in cases. About half said, No, we think it’s not likely. And one said, Flip a coin."
It is an accurate reflection of how unpredictable the influenza virus can be. Although flu activity has been waning for the third week in a row, health officials warn that there are still four to five months left in the official influenza season, plenty of time for the virus to make its rounds and find new hosts. "The story of pandemics, and the story of H1N1 in general, is the story of persistent uncertainty where we never quite know what we are going to get or when," says Dr. Irwin Redlener, director of the National Center for Disaster Preparedness at the Columbia University Mailman School of Public Health.
How severe the current H1N1 pandemic seems depends on what you use as a measuring stick. Compared with previous pandemics, like the 1918 Spanish flu, which killed 20 million people and infected up to 40% of the world’s population, or even the far less deadly 1957 and 1968 bouts with a strain of H1N1 influenza similar to the 2009 strain, things don’t seem as bad this time around. Fewer people are getting severely ill when infected, and fewer have died or required hospitalization from the flu than in previous pandemics.
Marc Lipsitch, an epidemiologist at the Harvard School of Public Health, and his colleagues studied the course of the 2009 H1N1 pandemic last spring in two cities — New York and Minneapolis — and determined that 0.048% of people who developed symptoms of H1N1 died, and 1.44% required hospitalization. Based…
Tags: CDC, death rate, H1N1, health officials, hospitalization rate, infection rate, second wave, swine flu, vaccine
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by ilene - November 20th, 2009 8:11 pm
By Ilene
The good news is that the number of new cases appears to be dropping off in most of the United States. More good news is that the swine flu vaccine appears to be reasonably safe, with no increases in serious events, including death, above the expected baseline rate. The not-so-good news is that a currently noted "peak," in flu language, is temporary. Additional waves of increasing illness are expected. Other bad news is that pediatric deaths from the swine flu are already considerably higher than in seasonal flues, and the numbers are expected to continue rising. In addition, viruses with specific mutations, D222G or D225G, and a mutation resulting in tamiflu resistance, are being isolated from cases in multiple locations.
Estimated Statistics:
Update from the CDC, Weekly 2009 H1N1 Flu Media Briefing, Anne Schuchat, director of vaccination and respiratory disease at the C.D.C:
these estimates will give a single number and then a range, a lower and upper estimate around each number…. So for April through October 17th, we estimate the 22 million people have become ill from pandemic influenza. We estimate 98,000 people have been hospitalized so far through October 17th. And the upper and lower estimates on hospitalizations are from 63,000 to 153,000. We estimate that 3,900 people have died so far in the first six months of the pandemic from this virus. And the estimates there are from 2,500 up through 6,100 people having died so far. We’ve been talking a lot about this pandemic being a younger person’s disease, that it’s disproportionately affecting children and young adults and relatively sparing the elderly, very different from seasonal flu… [In] children under 18, we estimate 8 million children have been ill with influenza, 36,000 hospitalized, and 540 children have died…
I do believe that the pediatric death toll from this pandemic will be extensive and much greater than what we see with seasonal flu…The numbers I’m giving are through the first six months through October. We have had a lot of disease since then and we’ll probably have a lot of disease going forward…
What does this look like compared to previous pandemics. The estimates I’m giving you are the first six months. This is April through the middle of October. We have a long flu season ahead of us. In typical seasonal flu we see disease from
…
Tags: cytokine storm, D222G Mutation, death rate, genetic changes, Guillain-Barre Syndrome, H1N1 virus, mutation, Norway, swine flu, tamiflu resistance, Ukraine, United States, vaccine
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by ilene - October 27th, 2009 11:55 am
John asks: "Why is the government trying to spread its public health message through children rather than parents?" Perhaps because a significant proportion of the nation’s parents distrust it and the pharmaceutical companies, so going straight to the kids may be a viable option. – Ilene
Remember when tobacco companies were accused of targeting children with advertisements and promotional items featuring cartoons?
Everyone thought it was terrible because children could be convinced smoking was cool by cartoons.
(Or something. This never made a whole lot of sense since we’ve never really had a child smoking problem in the United States. Sure sometimes kids will take a puff or two as an experiment but real smoking didn’t stop until much later and there was never any evidence that teenagers were convinced to start smoking because of cartoons.)
The thing that really creeped most people out was that the use of cartoons seemed aimed at undermining parental authority and influence, getting between kids and their mom and dad. Oh, and the fact that most people are convinced that smoking is deadly.
So what should we make of this advertisement promoting flu shots? Believe it or not, flu shots are pretty controversial. There are a lot of people who believe that serious health issues are associated with the shots, although the evidence for this seems scant. Many more people just don’t think the risk of childhood flu is really worth the quite common side effects, limited risks and cost of getting the shot.
And a few of us have figured out that you can pretty effectively be a free rider when it comes to vaccinations. When my brother enrolled his daughter in pre-school, he was told that chicken pox shots were mandatory. As a Roman Catholic, he objected to the vaccine on pro-life grounds (lung tissue from aborted fetuses are used to generate the vaccine) and pointed out that if everyone else at school was vaccinated, there’s no way his daughter would catch or spread the chicken pox. She was effectively but indirectly vaccinated.
In any case, the risks and benefits of getting a flu shot seem to be something that should be left up to parents rather than decided by bureaucrats. Certainly, the image of the
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Tags: Bubbles, Economy, Features, Finance, Financial Crisis, Health, Investing, regulation, stocks, swine flu, The Way We Live Now, vaccine, Wall Street
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by ilene - August 19th, 2009 11:12 am
By Alice Park, courtesy of TIME
Generally the fact that a vaccine appears to be as safe as the manufacturer had promised shouldn’t be news. It should be a given. But when it comes to the controversial vaccine against human papillomavirus (HPV), even the most straightforward data come with an asterisk.
The vaccine, called Gardasil and manufactured by Merck, is one of the first immunizations to protect against a cancer — in this case, cervical cancer, which is most commonly caused by infection with HPV. Because the virus is sexually transmitted, the Centers for Disease Control and Prevention (CDC) recommended in 2006 that girls get the vaccine at ages 11 and 12, before they become sexually active, so they have the best chance of avoiding the cancer and genital warts caused by HPV. States joined in, attempting to mandate HPV vaccination for school entry, but parents balked, in part because of concerns about encouraging promiscuity. It didn’t help that girls were prone to fainting after getting the shot or that more than two dozen girls died shortly after getting immunized.
To address those concerns, researchers at the CDC and the FDA, which keep track of adverse events related to vaccines once they are approved, now report in the Journal of the American Medical Association (JAMA) that the rate of adverse events associated with the 23 million doses of Gardasil administered since 2006 is similar to the prelicensing rate among the 21,000 girls and young women who tested it in clinical trials and to that of other vaccines.
That should be reassuring. But the study did find that users of Gardasil faint and develop blood clots more often than those receiving other shots. The clots are extremely rare, though. In about 90% of these cases, the girls may have been more vulnerable to developing clots because they smoked or were overweight or on birth control pills. "Was it that this age group also tends to have these risk factors or did the vaccine have some sort of role?" asks the CDC’s Dr. Barbara Slade, lead author of the paper. "We really don’t know."
It’s that uncertainty that is beginning to bother many physicians about the HPV vaccine. According to Dr. Charlotte Haug, editor in chief of the Journal of the Norwegian Medical Association and author of an editorial that JAMA…
Tags: CDC, cervical cancer, Gardasil, GlaxoSmithKline, HPV, human papillomavirus, Merck, vaccine
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Philip R. Davis is a founder Phil's Stock World, a stock and options trading site that teaches the art of options trading to newcomers and devises advanced strategies for expert traders...
Ilene is editor and affiliate program
coordinator for PSW.