An instantaneous, universal, programmable vaccine?


Efforts to immunize people against disease go back to at least 600 B.C., when the Chinese attempted to immunize people against smallpox by putting smallpox material in their nostrils (the permitting of which, I would think, would require a great deal of faith in your doctor).

Modern immunization began in 1796 when a British physician, Edward Jenner, noting that people who had had the much-less-deadly cowpox did not catch smallpox, inserted material from cowpox sores into the arm of a healthy eight-year-old boy. The boy caught cowpox, but when he was exposed to smallpox eight weeks later, he did not contract the often-fatal disease.

Vaccines have since become a mainstay of public health. Their impact has been enormous. Consider measles: in 2007, according to the World Health Organization, 197,000 people died of measles worldwide. That’s 540 people a day, or 22 people an hour. That sounds awful, and it is: but it’s tremendously good news compared to just a few years ago. Thanks to a worldwide focus on measles vaccinations, measles deaths dropped 74 percent between 2000 and 2007, and a whopping 90 percent in the eastern Mediterranean and Africa regions.

Vaccines, as I’ve written before, work by tricking the body’s immune system into treating them as a full-fledged infection. Traditional vaccines consist of disease-causing organisms that have been either inactivated or killed, so they can’t cause disease. However, they still trigger the immune system’s normal response to the presence of foreign bacteria or viruses: the creation of antibodies specifically designed to attack them.

These antibodies remain in place after vaccination, so that if the full-strength bacteria or viruses of the same type enter the body in the future, the immune system has antibodies available to attack them immediately, destroying them before they can cause infection or disease.

But vaccines have one major drawback: it may take days or even weeks for them to build a person’s immunity. If you’re exposed to a fast-moving, deadly disease before that immunity is in place, your vaccination may do you no good. As well, vaccine development, particularly in the case of influenza, is sometimes a guessing game: scientists have to try to figure out which particular strain is most likely to strike a particular area, and they’re not always right.

Which is why the report of a new type of vaccine developed at the Scripps Research Institute in California is so exciting: it holds out the tantalizing promise of instant immunity.

A team led by Professor Carlos Barbas III injected mice inflicted with either melanoma or colon cancer with a vaccine designed to trigger a universal immune response–but not on its own. It remained inert until joined by a second injection of “adapter molecules”–small molecules tailor-made to recognize specific cancer cells. The adapter molecules essentially programmed the vaccine, telling it what it should generate an immune response to.

The result? Those mice–and only those mice–that received both the vaccine and the adapter compound generated an immediate immune attack on the cancer cells, which significantly inhibited the growth of their tumors.

This is the first time this kind of chemical-based, rather than biologically based, vaccine has been successfully designed and tested, and the possibilities are exciting. Barbas points to current vaccines against HIV, the virus that causes AIDS. Many antibodies are generated, but most aren’t able to target the active part of the virus. Using the new approach, it may be possible to hone in on the active part of HIV much more precisely and effectively.

“It opens up the possibility of having antibodies primed and ready to go in the time it takes to receive an injection or swallow a pill,” Barbas says. “This would apply whether the target is a cancer cell, flu virus, or a toxin like anthrax that soldiers or even civilian populations might have to face during a bioterrorism attack.”

Three clinical trials are already underway by the pharmaceutical giant Pfizer to test this new approach against cancer and diabetes. Babas plans to continue his own research with cancer, and explore the use of this approach against HIV and infectious diseases for which no vaccines currently exist, the goal being to create adapter molecules specific to those diseases.

Keep your fingers crossed!

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