The Upside of Ebola May Be Vaccines
WHY YOU SHOULD CARE
Because new scientific strategies may ultimately get vaccines more easily, and more cheaply, to the people who most need them.
By Melissa Pandika
They don’t have the name recognition of Ebola, but lymphatic filariasis and schistosomiasis are killer viruses in developing countries. Big killers. Indeed, combined with other illnesses like malaria and pneumonia, infectious diseases account for 1 in 7 deaths worldwide. But good luck trying to convince drug companies to put resources and funds into developing vaccines for most of them: Diseases in poor countries don’t make for lucrative markets.
But a relatively new scientific strategy is trying to cut the cost and time of developing a vaccine, on average, by half a billion dollars and up to 15 years. Think vaccines that inoculate against a wide variety of strains, not just one, thereby eliminating the arduous and expensive process of isolating molecules. Or boiling the manufacturing process down to fewer steps. It’s a big shift from previous efforts to bridge the vaccine gap by, for instance, providing pharmaceutical makers incentives for R & D, or guaranteeing them markets for certain products. This isn’t about markets. It’s about microbiology.
Ebola, of course, is the impetus for some of this. Some researchers blame inefficiencies in the pharmaceutical industry for the current Ebola epidemic and its failure to produce a vaccine already. Only after the epidemic kicked into gear did drug companies race to develop a vaccine. Prioritizing vaccine development not only for diseases that affect poorer regions (like Ebola), but also for cholera and pneumonia, could prepare us for future outbreaks, advocates say. “Hopefully this Ebola epidemic will wake us up,” says Mark Kane, a Seattle-based immunization policy consultant and former president of the Gavi Fund, which tries to make vaccines more accessible to the poor.
To understand how scientists are making cheaper vaccines, you have to know a bit about how vaccines are normally made. Vaccines expose the body to an antigen, which is a harmless fragment of a disease-causing agent. The immune system recognizes the antigen as foreign and cranks out proteins called antibodies, which attack the fragment if it reappears. Making vaccines typically involves isolating antigens unique to a few different strains of any disease and mixing them together.
But isolating and mixing antigens is an expensive process, and for some diseases, vaccines have been developed only for a few strains. So some scientists are using the entire bacterium or virus to make vaccines, instead of just the antigen. In Massachusetts, researchers from the Program for Appropriate Technology in Health, a nonprofit, and Boston Children’s Hospital are using this approach with the pneumococcus (see: pneumonia) bacterium, in which case the current vaccine targets only the 13 strains most common in the U.S. and Europe. The new vaccine would target all 90, since the whole bacterium includes proteins found in every strain. A phase I study of a whole-cell vaccine administered to healthy U.S. adults showed promising results, and it’s now in clinical trials in Kenya. The researchers have also joined forces with Bio Farma, a state-owned vaccine manufacturer in Indonesia, to produce the vaccine.
… taxpayers pay for research, shareholders get rich and poor people may or may not get any benefit from these vaccines.
Why haven’t scientists used the whole-bacterium approach all along? They used to in the 19th century, but it fell out of favor because introducing an entire bacterium or virus often triggers an immune response strong enough to make patients feel ill — uncomfortable, though not dangerous, symptoms, says Kane. And definitely not as dangerous as the full-blown disease. That said, there are some diseases that are too dangerous for a whole-organism approach, like hepatitis B and C and human papillomavirus (HPV); injecting DNA or RNA from these organisms would cause cancer.
Another approach involves making a vaccine using a handful of proteins found in all strains of the disease. Scientists sometimes also make vaccines by tethering a sugar unique to one strain to a protein found in a few different strains — an expensive process that doesn’t protect against every strain of the disease. Other vaccine researchers are fighting disease with bacteria.
In fact, Antonio Campos-Neto, director of the Center for Global Infectious Disease Research, has turned the Streptococcus mitis bacteria that normally dwell in the mouth, gut, vagina, anus and other mucus-lined surfaces into living vaccine factories that grow and divide, churning out an endless supply of vaccine. (He injects the bacteria with genes that instruct them to produce fragments of the viruses, and they also dispatch antibodies to these areas.) The best part: It’s a relatively cheap solution. “It’s fundamentally a bacteria that grows in culture,” he says. “It can’t be more affordable than that.”
But it’s still the early days. Many vaccine production methods for poorer countries have yet to be tested in human clinical trials, including Campos-Neto’s. And although they might be cheaper, they still require funding.
For now, a sense of urgency — and injustice — pushes some scientists forward. “We have a situation where taxpayers pay for research, shareholders get rich and poor people may or may not get any benefit from these vaccines,” Kane says. “The whole system is now broken.”
- Melissa PandikaContact Melissa Pandika