NSTMF
Medicine

Fighting the Fight: Dr. David Baltimore

The NSTMF explores the extensive work Dr. Baltimore has done to uncover the HIV vaccination.

Over the last century, brave generations of researchers have conquered polio, measles, tuberculosis and other diseases that once ravaged populations.

We live in an era where cancer is no longer a death sentence, a simple pill can prevent pregnancy, and advanced imaging technology can diagnose anything from broken bones to microscopic tumors.

It’s difficult to dispute the power of modern medicine – a field so advanced that the right amount of funding and brainpower make anything seem achievable.

Almost anything, that is.

More than 30 years after its official discovery, an enigma of enigmas still puzzles those who have dedicated their life’s work to its demise.

Though it has slipped from the headlines, the Human Immunodeficiency Virus – HIV, for short – still lives among us, teasing immunologists with small breakthroughs that deliver more questions than answers.

“It’s humbling,” said biologist David Baltimore, a professor and former president of the California Institute of Technology. “The scientific community is used to solving problems.”

David Baltimore receiving the 1999 NMS from President Bill Clinton

AIDS, the disease caused by HIV, first garnered publicity in 1981 after the U.S. Centers for Disease Control and Prevention published a “Morbidity and Mortality Weekly Report” describing infections and weakened immune systems among five gay men in Los Angeles.

That July, the New York Times published an article about a “rare cancer” in 41 homosexual men.

“Initially, it was thought to be a gay man’s disease,” said Baltimore. “People who had a religious view thought it was retribution for violating God’s precepts.”

Medical experts, of course, knew better.

A decade earlier, Baltimore, now 78, laid the foundation for the discovery of HIV.

His work demonstrated how a subset of viruses can reverse the flow of information in cells by violating the central dogma of biology, a framework for how genetic data flows from DNA to RNA.

Baltimore won the 1975 Nobel Prize for showing how these so-called “retroviruses” reverse this process, moving information from RNA back into DNA.

The initial discovery of this reverse transcription, the method by which HIV reproduces itself, arguably saved thousands of lives by expediting the development of early treatment drugs in the late 1980s.

Within a few years, HIV went from a terminal diagnosis to a manageable condition.

“The most important thing has been done. We now have drugs that will stop the symptoms,” said Baltimore, who was awarded the National Medal of Science in 1999. “A person with HIV will generally die of something else – not of AIDS.”

The drugs, however, do not prevent an HIV patient from spreading the virus to others.

Only a true cure – “putting the genie back in the bottle,” as Baltimore calls it – could quash HIV altogether, eradicating the world of a disease that still ravages poorer countries lacking access to antiretroviral drugs.

In 2015, 1.1 million people died from AIDS-related illnesses, according to the World Health Organization.

More than 70 percent of those deaths happened in Africa, home to 15 percent of the world’s population.

By comparison, the Americas accounted for nearly six percent of AIDS-related deaths in 2015.

“AIDS is still killing a lot of people,” Baltimore said. “Most of us who continue to work on it are doing so with an eye to preventing the spread in the less developed world.”

Baltimore’s latest treatment research attempts to tackle HIV’s ability to evade immune attack, a feature that sets it apart from other retroviruses.

“Almost all viruses are sensitive to the immune system,” Baltimore said. “But HIV developed a very strong resistance. Almost no one can fight it off.”

Recently, Baltimore co-founded Calimmune, a private company that investigates gene therapies to control HIV.

The company, headquartered in Arizona, developed a method for delivering continual high levels of antibodies to neutralize HIV.

“We’ve developed a ‘vector’ that will carry the genes for the antibodies into a person, into their muscles,” Baltimore said. “Then they’ll make the antibodies themselves.”

Initial experiments have successfully helped non-human primates and mice evade infection when exposed to the virus, Baltimore said.

A trial to test the technique on humans is currently in the works.

Dr. Baltimore in the lab.

“Ultimately, I think we need a vaccine to prevent the spread,” Baltimore said, adding that “there are no clinical trials that have done anything except suggest a new direction for research.”

In December 2016, hope was renewed as researchers began a new test in South Africa – the largest study of HIV vaccine effectiveness since 2009.

The current study, called HVTN 702, aims to enroll 5,400 men and women. The vaccine is based on RV144, a clinical trial in Thailand that modestly prevented HIV.

“If deployed alongside our current armory of proven HIV prevention tools, a safe and effective vaccine could be the final nail in the coffin for HIV,” Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases at the National Institutes of Health, said in a news release.

Fauci, winner of the 2005 National Medal of Science, has made influential research contributions on how HIV destroys the body’s defenses.

“Even a moderately effective vaccine would significantly decrease the burden of HIV disease over time in countries and populations with high rates of HIV infection, such as South Africa,” he added.

Despite this latest trial, Baltimore isn’t optimistic about seeing a true cure in our lifetimes.

“There’s been a lot of work done – there’s a lot of new information – but nothing has led to a formula for how to make a vaccine,” he said. “It’s more than a shame.”

Where many have tried, all have failed.

“Maybe someone will come up with a surprise,” Baltimore said. “I just don’t think it’s going to be easy.”