The Upside of Ebola May Be Vaccines

Tuesday, February 24, 2015

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 it kicked into gear did drug companies race to develop a vaccine. Prioritizing vaccine development for diseases that affect poorer regions, like Ebola, but also 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 that 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 bacteria 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, where 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 in healthy U.S. adults of whole-cell vaccine 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.

Why haven’t scientists used the whole-bacteria 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.

Source: OZY (link opens in a new window)

Categories
Health Care
Tags
infectious diseases, malaria, vaccines