New Vaccine For HIV

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Potential new vaccine blocks every strain of HIV

A new drug candidate is so potent against all strains of HIV, researchers think it could work as a new kind of vaccine.

Developed by researchers from more than a dozen research institutions and led by a team at the Scripps Research Institute in the US, the drug is effective against doses of HIV-1, HIV-2 and SIV (simian immunodeficiency virus) that have been extracted from humans or rhesus macaques - including what researchers consider to be the ‘hardest-to-stop’ variants. It worked against doses of HIV that are way higher than what would be transmitted between humans, and works for at least eight months after injection.

"Our compound is the broadest and most potent entry inhibitor described so far,” lead researcher Michael Farzan from the Scripps Institute said in a press release. "Unlike antibodies, which fail to neutralise a large fraction of HIV-1 strains, our protein has been effective against all strains tested, raising the possibility it could offer an effective HIV vaccine alternative.”

While traditional vaccines work by delivering a tiny, weakened dose of a virus to train your immune system to thwart an actual attack, this drug does something quite different. The way HIV infects a person is by targeting their T lymphocytes - a very specialised type of white blood cell - and injecting its own genetic material inside to transform them into HIV-producing machines. So, quite literally, it turns our immune systems against us. 

But what Farzan’s team has discovered is that a particular type of protein found on the surface of white blood cells can actually bind to the surface of the HIV virus in two different places simultaneously, which means that not only does the virus no longer have a chance to change the position of its receptors to escape, it’s also being blocked from entering the T lymphocyte cells.

"When antibodies try to mimic the receptor, they touch a lot of other parts of the viral envelope that HIV can change with ease,"said one of the team, Matthew Gardner, from the Scripps Institute. "We've developed a direct mimic of the receptors without providing many avenues that the virus can use to escape, so we catch every virus thus far.”

According to James Gallagher at BBC News, the vaccine would be delivered via a weak, harmless type of virus that would introduce a section of DNA to a patient’s healthy muscle cells, containing instructions for how to produce this HIV-blocking protein. The protein would then be pumped out into the bloodstream over and over, protecting the patient from being infected over several months. The team reported inNature that the effects of the drug lasted for at least 34 weeks in their monkey subjects, but they think they could get it to last for years, perhaps even decades.

"We are closer than any other approach to universal protection, but we still have hurdles, primarily with safety for giving it to many, many people,” Franzen told the BBC. One such concern is that no one really knows what the long-term implications would be for a person who is having an anti-HIV response being pumped around their body non-stop. The team will be looking into this when they get their human trials underway.

"In the absence of a vaccine that can elicit broadly protective immunity and prevent infection, and given the lack of major breakthroughs on the horizon to provide one, the idea of conferring potent, sustained vaccine-like protection against HIV infection through gene therapy is certainly worth strong consideration,” Nancy Haigwood from the Oregon Health & Science University in the US, who wasn’t involved in the study, told the BBC. 

Source: BBC News

New Vaccine For HIV

6:43 AM AIDS, featured, health, HIV, Medicine, vaccine

Vaccine for Lung Cancer

Cuba Has a Lung Cancer Vaccine—America Wants It

Cuba has for several years had a promising therapeutic vaccine against lung cancer. The 55-year trade embargo led by the US made sure that Cuba was mostly where it stayed. Until—maybe—now.

The Obama administration has, of course, been trying to normalize relations with the island nation. And last month, during New York Gov. Andrew Cuomo’s visit to Havana, Roswell Park Cancer Institute finalized an agreement with Cuba’s Center for Molecular Immunology to develop a lung cancer vaccine and begin clinical trials in the US. Essentially, US researchers will bring the Cimavax vaccine stateside and get on track for approval by the Food and Drug Administration.

“The chance to evaluate a vaccine like this is a very exciting prospect,” says Candace Johnson, CEO of Roswell Park. She’s excited, most likely, because research on the vaccine so far shows that it has low toxicity, and it’s relatively cheap to produce and store. The Center for Molecular Immunology will give Roswell Park all of the documentation (how it’s produced, toxicity data, results from past trials) for an FDA drug application; Johnson says she hopes to get approval for testing Cimavax within six to eight months, and to start clinical trials in a year.

How did Cuba end up with a cutting edge immuno-oncology drug? Though the country is justly famous for cigars, rum, and baseball, it also has some of the best and most inventive biotech and medical research in the world. That’s especially notable for a country where the average worker earns $20 a month. Cuba spends a fraction of the money the US does on healthcare per individual; yet the average Cuban has a life expectancy on par with the average American. “They’ve had to do more with less,” says Johnson, “so they’ve had to be even more innovative with how they approach things. For over 40 years, they have had a preeminent immunology community.”

Despite decades of economic sanctions, Fidel and Raul Castro made biotechnology and medical research, particularly preventative medicine, a priority. After the 1981 dengue fever outbreak struck nearly 350,000 Cubans, the government established the Biological Front, an effort to focus research efforts by various agencies toward specific goals. Its first major accomplishment was the successful (and unexpected) production of interferon, a protein that plays a role in human immune response. Since then, Cuban immunologists made several other vaccination breakthroughs, including their own vaccines for meningitis B and hepatitis B, and monoclonal antibodies for kidney transplants.

The thing about making such great cigars is, smoking is really, really bad for you. Lung cancer is the fourth-leading cause of the death in Cuba. Medical researchers at the Center for Molecular Immunology worked on Cimavax for 25 years before the Ministry of Health made it available to the public—for free—in 2011. Each shot costs the government about $1. A Phase II trial from 2008 showed lung cancer patients who received the vaccine lived an average of four to six months longer than those who didn’t. That prompted Japan and some European countries to initiate Cimavax clinical trials as well.

To be fair, Cimavax probably won’t be a game-changing cancer drug in its current form. The vaccine doesn’t attack tumors directly, instead going after a protein that tumors produce which then circulates in the blood. That action spurs a person’s body to release antibodies against a hormone called epidermal growth factor, which typically spurs cell growth but can also, if unchecked, cause cancer. (Although most people normally think of a vaccine as something that prevents a disease, technically a vaccine is a substance that stimulates the immune system in some way.) So the point of Cimavax is to keep lung tumors from growing and metastasizing, turning a late-stage growth into something chronic but manageable.

But in the US and Europe, people with lung cancer already have treatment options with the same goal. Roswell Park researchers say they plan to explore the vaccine’s potential as a preventative intervention—making it more like a traditional vaccine. Furthermore, epidermal growth factor plays an important role in many other cancers, like prostate, breast, colon, and pancreatic cancer. “All those things are potential targets for this vaccine,” says Kelvin Lee, an immunologist at the company. Mostly for financial reasons, Cubans didn’t test Cimavax that way at all.

And that drug isn’t the only one with potential in the Cuban pharmacopeia. Thomas Rothstein, a biologist at the Feinstein Institute for Medical Research, has for six years worked with the Center for Molecular Immunology on another vaccine to treat lung cancer called Racotumomab, with an entirely different mechanism. (It messes with a particular lipid found in tumor cell membranes.) “Investigators from around the world are trying to crack the nut of cancer,” Rothstein says. “The Cubans are thinking in ways that are novel and clever.”

Although President Obama has used his executive power to lift some restrictions against medical and research equipment, Congress must lift the Cuban embargo before collaborative research can ramp up. Johnson hopes to see Cuba embrace more entrepreneurialism in science, and see the US soak up more creative approaches to medical research. Constrained by politics, the Cuban researchers had to innovate in ways the US and Europe did not. Now maybe they’ll be able to teach their colleagues what they learned.

Vaccine for Lung Cancer

8:43 AM Cancer, featured, health, Medicine, vaccine