Archive for December, 2011

Interview with Jonas Salk, developer of the polio vaccine

Sunday, December 11th, 2011 (last updated)

Jonas Salk (October 28, 1914 – June 23, 1995) was an American medical researcher and virologist best known for his discovery and development of the first safe and effective polio vaccine. Until 1955, when the Salk vaccine was introduced, polio was considered the most frightening public health problem of the post-war United States. Annual epidemics were increasingly devastating. The 1952 epidemic was the worst outbreak in the nation’s history. Of nearly 58,000 cases reported that year, 3,145 people died and 21,269 were left with mild to disabling paralysis, with most of the victims children.

Day at Night was a popular public television series hosted by James Day. The series features fascinating interviews with notable cultural and political figures conducted in the mid 1970’s. The interview with Jonas Salk dates April 28, 1974.

Source:
CUNY TV, the non-commercial cable television station of the City University of New York.

Intranasal Norovirus demonstrating clinical efficacy

Saturday, December 10th, 2011 (last updated)

Norovirus causes cramping, diarrhea and vomiting, and spreads easily from person to person, often in crowded, closed places like cruise ships. Each year, 21 million cases of norovirus occur in the United States, according to background information in the small new study published in the Dec. 8 issue of the New England Journal of Medicine.

“It is possible to prevent infection and illness with a vaccine for norovirus,” said Dr. Robert Atmar, a professor of medicine and molecular virology at the Baylor College of Medicine in Houston. But many questions remain unanswered, he said. For example, “we have to figure out the best way to give it and how long protection lasts.”

The new study included 98 people who received the vaccine or an inactive placebo. All of the participants tested positive for a gene that makes them more susceptible to the norovirus, the FUT2 gene.

Those who received the new vaccine were less likely to develop the stomach bug than their counterparts who received the placebo, the study showed. What’s more, they were also affected by the bug less frequently than their counterparts who did not receive the vaccine. Of recipients, 70 percent of people responded to the vaccine as evidenced by antibody levels in their bloodstream.

The new vaccine is given as two doses three weeks apart via a nasal spray. There were no safety issues seen in the new study. Side effects included stuffy nose and sneezing and were equally likely to occur in those who received the placebo. The new study was supported in part by LigoCyte Pharmaceuticals, maker of the vaccine.

Source:
USA Today & New England Journal of Medicine & Vaccinenation

Intranasal vaccine effective against Norwalk virus illness

Wednesday, December 7th, 2011 (last updated)

Two doses of an intranasal virus-like particle (VLP) vaccine, containing the  adjuvants chitosan and monophosphoryl lipid A, protect healthy adults against Norwalk virus, study results published in the Dec. 8 issue of the New England Journal of Medicine indicate.

Robert L. Atmar, MD, of Baylor College of Medicine in Houston, and colleagues assessed the vaccine’s safety, immunogenicity and efficacy in preventing acute viral gastroenteritis after challenge with a homologous Norwalk virus strain, genotype GI.1. A total of 90 healthy adults (aged 18 to 50 years) were randomly assigned to receive two doses of vaccine (47 participants) or placebo (43 participants). Eighty-four of the participants were subsequently inoculated with Norwalk virus and were monitored for infection and symptoms; 77 of these patients were included in the per-protocol analysis.

Vaccination significantly reduced the frequency of Norwalk virus gastroenteritis and infection, the researchers found, with 69% of placebo recipients experiencing gastroenteritis vs. 37% vaccine recipients. Norwalk virus infection occurred in 82% vs. 61% for placebo and vaccine recipients, respectively. Overall, 70% of people in the vaccination group showed a Norwalk virus-specific IgA seroresponse.

Adverse events were similar among patients in the vaccination and placebo groups, with nasal stuffiness, nasal discharge and sneezing among the most commonly reported symptoms after vaccination.

“This study shows that it may be possible to use a vaccination strategy to prevent norovirus disease.,” the authors wrote.

Source:
The Clinical Advisor & New England Journal of Medicine

Scientists have developed a vaccine that protects mice against a deadly form of the Ebola virus.

Tuesday, December 6th, 2011 (last updated)

First identified in 1976, Ebola fever kills more than 90% of the people it infects.

The researchers say that this is the first Ebola vaccine to remain viable long-term and can therefore be successfully stockpiled.

The results are reported in the journal Proceedings of National Academy of Sciences.

Ebola is transmitted via bodily fluids, and can become airborne. Sufferers experience nausea, vomiting, internal bleeding and organ failure before they die.

Although few people contract Ebola each year, its effects are so swift and devastating that it is often feared that it could be used against humans in an act of terrorisme.

All previously developed vaccines have relied on injecting intact, but crippled, viral particles into the body.

Long-term storage tends to damage the virus, paralysing the vaccine’s effectiveness.

The new vaccine contains a synthetic viral protein, which prompts the immune system to better recognise the Ebola virus, and is much more stable when stored long-term.

The vaccine protects 80% of the mice injected with the deadly strain, and survives being “dried down and frozen,” said biotechnologist Charles Arntzen from Arizona State University who was involved in its development.

He said the next step is to try the vaccine on a strain of Ebola that is closer to the one that infects humans.

Source:
BBC News & PNAC

HPV vaccination program in schools

Sunday, December 4th, 2011 (last updated)

Recent research into the school-based HPV vaccination program suggests there is a lack of understanding surrounding the vaccine, with some girls frightened of receiving the injection. Similar issues in the UK have caused a school to withdraw the program. We speak to research associate Spring Cooper who works in Paediatrics & Child Health at Sydney University to find out what can be done to ensure the same does not happen in Australia.

Source:
6 minutes video

Lab mice point way to HIV vaccine

Thursday, December 1st, 2011 (last updated)

Tests on lab mice have opened up a new path towards a vaccine against HIV, one of the most frustrating quests in the 30-year history of AIDS, scientists have reported.

Genetically modified mice fought back the human immunodeficiency virus (HIV) after they had been injected with genes to make antibodies, the first line of defence in the immune system, the report said in the journal Nature.

First identified in 1981, AIDS has claimed at least 25 million lives, although the annual toll is falling sharply from the peak of the pandemic in response to drug treatment.

But AIDS campaigners say the pandemic will only be crushed once a vaccine emerges. So far, in clinical trials, only one candidate formula has had even a modest effect, providing a shield of only 31 percent against the risk of HIV infection.

This has prompted researchers to return to the drawing board, to look for “broadly neutralising antibodies” – Y-shaped proteins that are the immune system’s foot soldiers – among the tiny number of people with an innate ability to resist HIV.

So far, this trawl has turned up around 20 so-called “bNAbs,” but there are big unknowns as to how they work and, if so, whether they can be made into a deliverable vaccine.

Delving into this, a team led by David Baltimore at the California Institute of Technology (Caltech) says it has developed a way to deliver bNAb-making genes to lab mice.

The rodents were engineered to carry human cells that allow HIV to penetrate and reproduce.

The approach, called Vectored Immuno Prophylaxis, or VIP, entails using a harmless virus as a “Trojan horse” in which they tucked the genes able to turn out specific bNAbs.

They then injected the virus into the leg muscles of the mice, where it holed up in cells, enabling the bNAb genes to produce antibodies in response to HIV.

The mice were first challenged with just one nanogram of AIDS virus – enough to infect most non-treated mice that received it – but the dose was eventually cranked up to 125 nanograms without problems. There were no signs of any side effects.

“VIP has a similar effect to a vaccine but without ever calling on the immune system to do any of the work,” said Alejandro Balazs, lead author of the study, in a press release issued by Caltech.

“Normally, you put an antigen or killed bacteria or something into the body, and the immune system figures out how to make an antibody against it. We’ve taken that whole part out of the equation.”

The team stressed that the jump from mice to humans is large.

“We’re not promising that we’ve actually solved the human problem,” said Baltimore. “But the evidence for prevention in these mice is very clear.”

He added the team was drawing up plans to cautiously test the method in small-scale human clinical trials.

Source:
Nature & The Australian