A major challenge facing global health is the disparity between the time it takes to develop a new therapeutic and the time until that therapeutic becomes obsolete due to drug resistance. Drug resistance is emerging against virtually every current therapeutic drug against global health diseases. Malaria is a classic example, where the use of symptomatic diagnosis, incomplete courses of treatment, and counterfeit drugs led to resistance against quinine, although that drug is still sold in some malaria-endemic regions. Malaria has also become resistant to chloroquine, sulfadoxine-pyrimethamine, mefloquine, and it is only a matter of time before resistance to the artemisinin family emerges (see Table). Many other diseases are also resistant, however, particularly the bacterial infections due to the fast lifecycles of bacteria and the ease with which they transfer genes horizontally. Ironically, the more antibiotic is available, the faster the emergence of resistance due to the effects mentioned above.
Resistance to malaria drugs. Source: P.B. Bloland, "Drug resistance in malaria", WHO, 2001.
A chart of the number of new antibiotics on the market per decade shows a steep decline in the past 20 years, to almost none today. This phenomenon is likely to be due to a number of causes, including market share, difficulty of discovering new antibiotic modes of action that evade resistance, and the lucrative potential of drugs for other first-world diseases including cancer. This notwithstanding, the trend is towards fewer new antibiotics and faster emergence of resistance.
Number of new antibiotics entering market by decade, 1940-2000. Data from: http://en.wikipedia.org/wiki/Timeline_of_antibiotics
The story is even more urgent when we consider vaccines. Vaccines are held as the silver bullet of global health because they are the only treatment method that provides long-term protection, significant knock-on effects within populations due to immunized individuals (known as herd immunity), and wide availability at low cost once the vaccine is developed. However, the timeline for development of new vaccines is long and arduous. Even here there is resistance, including the H1N1 strain of influenza, whooping cough, and meningitis C.
Exact numbers on how long it takes to develop a vaccine are hard to find, as this depends on the disease target, but a general estimate is between 9 and 14 years. The cost also varies, but can reach well into the hundreds of millions of dollars ($300-800 million). In contrast, H1N1 resistance to Tamiflu emerged in just under 5 years. As you can see, the timelines don’t match up – we are fighting a losing battle.
The solution is twofold. First, application of emerging technologies and methods to disease target discovery and potential vaccine candidates will speed the time it takes to develop a candidate vaccine that can enter clinical trials. After this point is where the policy and the economics enter. Although the research is expensive, the clinical trials are extremely expensive. There needs to be a better way for drug companies to make the money they need to develop these vaccines, which will undoubtedly save millions of lives. The answer is upon us, I think. Within the last 10 years, several large pharmaceutical companies have spun off nonprofit vaccine development organizations focused on vaccines for neglected diseases. The nonprofit model fits these challenges well because there is virtually no way to make money on these vaccines and drugs. Once they are developed, they will be distributed at very low cost to the world’s critically poor, making sales an nonviable method to recoup costs. These nonprofits can apply for grants, raise donations, and use other methods to fund the critical research that needs to be done in order to ensure that the vaccines are developed, and that they are safe and effective.
Here’s the happiest news of all – you can help make this happen! Power to the people! You can donate or help raise funds for groups like the Sabin Vaccine Institute, the Novartis Vaccines Institute for Global Health, and PATH that are doing this critically important work. I have included links to many of them on the “Get Involved” page. I encourage you to donate so that others may live.
