vaccine Archives - Humanosphere

vaccine

TB vaccine study dissapoints |

: tuberculosis patient, El Salvador

As a Reuters article from last week indicated, there were high hopes the results from a study of an experimental TB vaccine would show promise.

“In my own personal view, I will consider this (trial) to be a landmark or a watershed,” said Peggy Johnston, senior program officer at the Bill & Melinda Gates Foundation in Seattle. “If it is negative, it would be the first trial we can demonstrate that yes, we can conduct a clinical trial and get a solid answer. If it turns out to be at all positive, it will be a clear watershed for the field.”

Unfortunately, the study did not yield a positive result, at least in the latter sense. TB, though seldom in the news like HIV or malaria (or the threat of pandemic flu), remains one of the world’s biggest killers and the bacteria is becoming increasingly drug -resistant. As a number of news articles reported on this latest attempt to find a better vaccine:

BBC and the Guardian both reported ‘Hopes for new TB vaccine dashed‘

NPR sounded a more hopeful note, saying that though this vaccine failed to protect infants there are lots of other candidate vaccines under study.

FILED UNDER: Science, tuberculosis, vaccine

October 31, 2012 | 2:52 PM | By Tom Paulson |

Seattle AIDS vaccine scientists celebrate new clues – and uncertainty |

Jim Kublin provides an overview of AIDS vaccine science at Seattle HVTN meeting

Seattle is home to the world’s largest HIV vaccine research network and, as a scientitic meeting here this week indicated, they’re quite comfortable with not knowing where they’re heading.

“We actually don’t know what the agenda is,” said Dr. Jim Kublin, executive director of the HIV Vaccine Trials Network (HVTN) based at Seattle’s Fred Hutchinson Cancer Research Center.

That drew a lot of laughs from the audience, since Kublin’s lecture title for the day was ‘Scientific Agenda, the Next Seven Years.’

“That’s the way science is,” Kublin told me after his talk. “Good science is based on uncertainty, on having an open mind and dealing with the unknown.”

But what makes it easier to laugh about not knowing where you’re going, he added, is that researchers today have a lot more tantalizing clues – beginning with the ground-breaking Thai vaccine trial known to this bunch as RV 144. Continue reading →

FILED UNDER: Science, Fred Hutchinson Cancer Research Center, HIV-AIDS, HVTN, Jim Kublin, RV 144, Seattle, South Africa, Thailand, vaccine

July 19, 2012 | 12:00 PM | By Tom Paulson |

ArsTechnica: The difficult search for a malaria vaccine |

Seattle writer Robert Fortner, in ArsTechnica, examines how far we have come in the search for an effective malaria vaccine.

This story is focused on what many consider the most promising malaria vaccine candidate, called RTS,S, made by GlaxoSmithKline decades ago and being tested (again) under improved formulations with funding from the Bill & Melinda Gates Foundation and the PATH Malaria Vaccine Initiative. As I’ve noted before, many experts are quietly expressing doubt RTS,S will work even though it has provided some new insights into the immunology of malaria.

Bob digs deeper into the evidence:

Photo by Caitlin Kleiboer

Testing the RTS/S malaria vaccine in Malawi

After clean water, vaccines may have saved more lives than any other public health intervention. Eradication of malaria, a disease that may have killed more humans than any other single cause, likely requires a malaria vaccine.

However, after nearly a century of research, today’s only candidate might not pack enough immunological punch to win deployment. Sadly, there are no obvious successors. Goals for vaccines set in 2006 are now approaching, but may not be possible to meet.

A quarter century of painstaking work has gone into the vaccine known as RTS,S, now in phase III clinical trials. But after numerous modifications and enhancements, RTS,S still protects only intermittently, 30 to 60 percent of the time.

This protection wanes, although over how many years or months is still being studied. The vaccine reduces disease but, so far, not deaths.

The organism that causes malaria has made vaccine development a challenge. Malaria is caused by the parasite Plasmodium rather than bad or “mal” air as thought long ago. The human genome, particularly in sub-Saharan Africa, chronicles our lengthy and ongoing battle with Plasmodium.

Strong selection pressure on humans has led to evolutionary gambits like the sickle cell trait—risking potentially lethal blood disorders to reduce susceptibility to malaria infection. But Plasmodium has kept the upper hand in many ways. The parasite continues to baffle the immune system with a complex genome reshuffled by sexual reproduction, a multi-stage life cycle that features antigenic shape-shifting, to avoid immune surveillance.

For pathogens like polio, the human immune system can develop durable, sterilizing immunity, which rids the body of the invader. Polio vaccines reliably trigger these natural mechanisms. For malaria, humans can acquire a kind of immunity and potentially even clear parasites completely. But the genetic diversity of Plasmodium falciparum allows it to often avoid such direct hits.

Acquired immunity is often a détente in which the parasite survives and reproduces at low levels that cause neither disease nor death. A study in western Kenya, for example, found 90 percent of a cohort was infected with falciparum even though not one of the 93 people was ill. Vaccines like RTS,S prod the immune system toward this partial protection, but there is concern that it isn’t reducing severe malaria enough.

Continue reading at ArsTechnica.

FILED UNDER: Health, Science, Bill & Melinda Gates Foundation, GlaxoSmithKline, malaria, Malariav Vaccine Initiative, PATH, Robert Fortner, RTS/S, vaccine

April 25, 2012 | 12:10 PM | By Tom Paulson |

MILLENNIALS

Infectious hope: When getting malaria makes sense |

Flickr, Aya Rosen

It’s World Malaria Day. There’s been great progress against malaria over the past decade but most experts agree the best hope is to find an effective vaccine. Seattle Biomed is one of the world leaders in malaria vaccine research, but testing these experimental vaccines relies on people volunteering to get the vaccine — and get bitten. What it’s like to get infected for science.

——————————————————————————————————————————-

By Cyan James, special correspondent

Cyan James

Lane Rasberry wants to better arm the world against malaria

“I’m going to get infected and I’m going to love it,” Lane Rasberry says with a smile.

Rasberry is about to spend at least five minutes with more than a dozen mosquitoes full of malaria parasites.

The mosquitoes huddle in a screened, pint-sized container, waiting for Rasberry to roll up his left sleeve, lay his forearm over the container, and drape a towel over his arm to simulate night. Then they launch, feeding on Lane until their breakfast clock runs out.

A Wikipedia editor by day, Rasberry also volunteers in a malaria vaccine trial at Seattle BioMed, where he belongs among a unique group of clinical subjects who intentionally get infected.

Why? For Rasberry, it’s because the research is both altruistic and convenient, and because it plays to his interest in science. “I actually enjoy participating,” he says, emphasizing research trials’ ability to create community and help others learn about scientific advances. Plus, since he grew up in Texas, the mosquitoes don’t really faze him.

Seattle Biomed, Earl Harper

Mosquito dissection

After Rasberry’s five minutes are up, a technician dumps his mosquitoes into an ethanol bath to kill them, then flicks off the mosquitoes’ heads, presses their torsos to extrude their innards, and swiftly isolates their salivary glands.

Cyan James

Skeeter dissection

The technician scans the tiny sickle-shaped glands under a microscope, searching for P. falciparum, the parasite that infects up to 500 million people with malaria every year and kills nearly two people every hour.

Continue reading →

FILED UNDER: Health, Science, Cyan James, malaria, Malcolm Gardner, Sara Healy, Seattle Biomed, Stefan Kappe, vaccine

February 27, 2012 | 9:47 AM | By Tom Paulson |

Seattle scientists to test world’s first vaccine against ‘black fever’ – leishmaniasis |

WHO

Boy with kala azar, viscerial leishmaniasis

There are many neglected diseases out there but not many as prevalent or as ravaging as visceral leishmaniasis, also known as black fever or kala azar — the ‘parasitic version of AIDS.’

Scientists at Seattle’s Infectious Disease Research Institute will soon begin testing an experimental vaccine they have designed to work against the most deadly form of this common parasitic disease spread by the bite of sand flies.

Leishmaniasis, in both its cutaneous (surface of the skin) and visceral (internal organ) forms, infects an estimated half million people every year on every continent except Australia and Antarctica. It is the second most common parasitic disease after malaria, but has until recently gotten little attention as a major global health problem.

Because the parasite attacks blood cells, immune system cells and also invades organs and bone marrow much like HIV, visceral leishmaniasis is sometimes called ‘parasitic AIDS.’

“Visceral leishmaniasis is a persistent and deadly global health problem,” said Steve Reed, IDRI founder and Chief Scientific Officer, who led the over twenty years of preclinical vaccine work. “Our partnership with India will speed the development of an effective vaccine and accelerate its control.”

The vaccine against visceral leishmaniasis (VL) that IDRI has created will be tested first for safety on 36 volunteers in Seattle and then the Phase I study will be expanded to sites in India, which suffers from a disproportionately high caseload of the disease.

The non-profit Seattle-based research organization has been working on leishmaniasis for decades but received a major boost in 2006 when the Bill & Melinda Gates Foundation awarded IDRI $32 million to find a vaccine against VL, kala azar.

As part of the grant, the Gates Foundation requires research organizations also develop a plan to make vaccines or drugs affordable in poor countries.

To reduce costs of the new vaccine, should it prove effective, IDRI is transferring its vaccine technology to an Indian drug firm, Gennova Biopharmaceuticals. Gennova has already opened a vaccine development center in Pune, India, where the company is based.

“With this clinical trial, we hope to launch a new era in the fight against Visceral Leishmaniasis,” said Franco Piazza, Medical Director at IDRI and leader of the vaccine’s clinical development. “For the first time, an advanced vaccine to prevent this devastating disease is being tested in people.”

U.S. Armed Forces Pest Management

A sand fly bite

While leishmaniasis is treatable today, the treatments are fairly toxic, cumbersome and often too expensive to use in poor communities. Some 500,000 people get infected every year, with an estimate 50,000 deaths per year, and the disease appears to be spreading.

Just as with mosquitoes, sand flies that carry the parasite appear to be expanding their range worldwide due to climate change, migration and other global changes.

FILED UNDER: Science, Infectious Disease Research Institute, leishmaniasis, Steve Reed, vaccine

November 3, 2011 | 11:22 AM | By Tom Paulson |

Lacking a dengue vaccine, scientists tinker with skeeter genes |

It’s rarely on most Americans’ minds, but worldwide dengue is a big killer. And it’s spreading fast.

The U.S. Centers for Disease Control and Prevention says there are anywhere from 50 to 100 million people infected every year with dengue — including a very small, but increasing number of Americans — and an estimated 50,000 deaths from this mosquito-born disease.

Here’s an interactive look (go to this link) at dengue around the world from HealthMap:

HealthMap, CDC

The number of cases of dengue have exploded over the past few decades in tropical and semi-tropical regions. Some believe this may be driven by climate change and an expanded range for the mosquito (Aedes aegypti, which also carries yellow fever).

WHO

Dengue cases over time

Others think shipping, cargo transportation, may be the main route of spread. This skeeter tends to like to live in urban and semi-urban areas.

Because of the global surge in dengue, the U.S. military and some pharmaceutical companies have stepped up efforts to develop a vaccine that can protect against the infection. The Bill & Melinda Gates Foundation has donated $60 million to the vaccine efforts as well as some more ‘innovative’ approaches such as modiying the genes of mosquitoes.

Earlier this week, a team of scientists (partly funded by Gates) reported success in a field trial of mosquitoes genetically modified so that their offspring die following reproduction. As the BBC noted, dengue can’t be fought with same tools as malaria, such as bed nets, primarily because these mosquitoes bite during the day time.

The successful field trial — which just tested the genetic tinkering’s effect on reproduction, not dengue transmission — has nevertheless raised concerns about unintended environmental side-effects, the New York Times reports.

The British biotech company pursuing this approach, Oxitec, had already raised some hackles earlier for too aggressively moving forward with their releasing modified mosquitoes into the wild.

Meanwhile, to much less media attention and fanfare, other scientists (many of them also funded by the Gates Foundation) are working on developing a vaccine against dengue. Here is one recent news brief about an ongoing trial.

For a broader overview of work on developing a vaccine, see the Dengue Vaccine Initiative.

FILED UNDER: Science, dengue, genetically modified organisms, vaccine

October 28, 2011 | 12:08 PM | By Tom Paulson |

Experts question Gates-Glaxo malaria vaccine report |

Flickr, Aya Rosen

Many of the world’s leading vaccine experts and the prestigious British journal Nature are raising questions about the potential efficacy of an experimental malaria vaccine — and the way it is being promoted by scientists supported by the Gates Foundation.

As Nature News’ Declan Butler reports in Malaria vaccine results raise scrutiny:

To judge from last week’s headlines, scientists had made a big breakthrough in the long campaign to create a malaria vaccine ….

Yet several leading vaccine researchers, who are critical of the unusual decision to publish partial trial data, argue that the results raise questions about whether the RTS,S candidate vaccine can actually win approval.

Continue reading →

FILED UNDER: Health, Science, Bill & Melinda Gates Foundation, GlaxoSmithKline, malaria, PATH, vaccine

October 25, 2011 | 12:03 PM | By Tom Paulson |

Three reasons not to get too excited about the Gates-Glaxo malaria vaccine |

Last week, the biggest news out of the Gates Foundation’s Malaria Forum were some interim results of an ongoing test of an experimental malaria vaccine.

Many, if not most, media reported the findings in somewhat hyperbolic fashion as a “major milestone,” a “breakthrough” or “world’s first malaria vaccine.”

Google News on the malaria vaccine

Despite the hype and fanfare, many experts at the Seattle meeting said this experimental vaccine (known as RTS,S) actually so far represents only incremental progress — a scientific achievement which may still turn out to have little practical utility in the real world. They usually only said so privately, given that the Gates Foundation preferred to hear “optimistic” assessments rather than cranky ones.

1. No breakthrough. Let’s first put to bed the claims that these findings represent a major milestone. In fact, the findings largely repeat earlier ‘interim’ results that have continued to find the vaccine protects only half of those immunized — and appears to wane fairly rapidly over time.

So that’s the first reason — a point also made in this (terribly titled) Huffington Post article A vaccine that works only half the time is not the shot in the arm malaria needs. The author, Tido von Schoen-Angerer, director of Médecins Sans Frontières‘ essential medicines campaign says:

But while the latest advance toward the development is scientifically important, there are several reasons to be cautious about the difference this vaccine could make, on the basis of current results.

2. The cost question. The second reason this halfway effective malaria vaccine may not work is cost. The manufacturer GlaxoSmithKline has refused to say what it thinks it will have to charge for the vaccine, other than to say it would be “at cost” plus 5 percent. Neither the PATH Malaria Vaccine Initiative, which is working with GSK on the malaria vaccine trial, or the Gates Foundation (which funds the PATH initiative) will say what price they think is feasible. Many say anything over a dollar might be too much for poor countries.

3. The science. It is promising that researchers have shown a vaccine against malaria is possible. But there’s a lot of other research out there indicating why it may be quite difficult to get a malaria vaccine that can perform as well as most of us expect a vaccine to perform — providing ideally something like 90 percent protection but hopefully not lower than 70 percent. Continue reading →