Outbreak

Over 95% of post‐mortem samples from the 1918 pandemic, which caused 50 to 100 million deaths, showed bacterial infection complications. The introduction of antibiotics in the 1940s has since reduced the risk of bacterial infections, but growing resistance to antibiotics could increase the toll from future influenza pandemics if secondary bacterial infections are as serious as in 1918, or even if they are less severe. We develop a valuation model of the option to withhold wide use of an antibiotic until significant outbreaks such as pandemic influenza or foodborne diseases are identified.

Influenza pandemic scenarios

Using real options theory, we derive conditions under which withholding wide use is beneficial, and calculate the option value for influenza pandemic scenarios that lead to secondary infections with a resistant Staphylococcus aureus strain. We find that the value of withholding an effective novel oral antibiotic can be positive and significant unless the pandemic is mild and causes few secondary infections with the resistant strain or if most patients can be treated intravenously. Although the option value is sensitive to parameter uncertainty, our results suggest that further analysis on a case‐by‐case basis could guide investment in novel agents as well as strategies on how to use them.

There have been roughly three global pandemic influenza outbreaks each century for the past four hundred years; each of which have resulted in larger numbers of infections and deaths. Secondary bacterial infections have been responsible for a significant proportion of deaths in previous pandemics. Pandemic preparedness plans call for maintaining stocks of antivirals, antibiotics, and vaccines; however, the value of stockpiling or conserving the effectiveness of antibiotics remains unexplored; despite the high morbidity of secondary bacterial infections; and the growing ineffectiveness of antibiotics due to the emerging public health threat of antibiotic-resistant superbugs.

Antibiotic resistance is a major barrier

In the event of a significant influenza pandemic, secondary infections caused by prevalent pan-drug resistant bacteria could be catastrophic. Effective antibiotics in the future are indispensable in the case of an influenza pandemic. In a new study published in the journal Health Economics, researchers at CDDEP, the University of Strathclyde in Scotland, and Wageningen University in the Netherlands developed a mathematical framework to estimate the value of investing in developing and conserving an antibiotic to mitigate the burden of bacterial infections caused by resistant Staphylococcus aureus during a pandemic influenza outbreak.

The model, which is based on UK preparedness plan assumptions; found that the value of withholding an effective novel oral antibiotic can be positive; and significant unless the pandemic is mild and causes few secondary infections with the resistant strain; or if most patients can be treated intravenously.”Although influenza is caused by a virus; which cannot be treated with antibiotics; secondary bacterial infections are a major cause of death and disability; and antibiotic resistance is a major barrier to treating these infections;” said Ramanan Laxminarayan.”This study shows that the value of an effective antibiotic against Staph infections; as an insurance policy against future pandemics; is between $3 and 4 billion at baseline.”