Microscopic image of Haemophilus influenzae

Applying science to flu pandemics

Are we better prepared for flu pandemics than we were in the past?

When Spanish flu hit in 1918, its cause was not known with certainty. The finger of blame was pointed at a bacterium, Haemophilus influenzae, often found in the lungs of people with flu.

In fact, H. influenzae is an opportunistic pathogen, thriving as a patient succumbs to the influenza virus. The virus causing human flu was not finally identified until 1933.

A flu vaccine came soon after – the US Army used vaccines during World War II. Flu vaccine production was insufficient for the pandemics of the 1950s and 1960s, but capacity is significantly greater now.

Antivirals were slower to arrive, first being developed in the 1960s. Oseltamivir and zanamivir were approved in 1999. Neuraminidase inhibitors were rationally designed (built to bind to a specific site on the enzyme), meaning that the emergence of resistance could be understood in molecular terms and (in theory) alternatives developed.

Another relatively new tool is genome sequencing. Viral genomes are short and can be sequenced rapidly, generating results within days. With many genome sequences available, the evolution of the virus can be mapped in fine detail. In conjunction with clinical information, such data may reveal genetic features responsible for enhanced virulence or other important traits, as well as patterns of gene swapping and virus spread.

Modelling is another new tool feeding into decision making. Computer simulations can be used to test the effects of outbreaks and various control measures, on scales ranging from the global to the local. There is also growing interest in using social media tools such as Twitter or Google searches to improve influenza forecasting.

Although inevitably simplifications, models can be refined as more is discovered about the virus and disease. While not the only factor influencing decision making, they can help to identify useful (or useless) interventions.

Lead image:

Light microscopy image of Haemophilus influenzae bacteria, an opportunistic pathogen often present in people infected with the flu virus.

Wellcome Library, London CC BY NC ND

References

Questions for discussion

  • Do you think we are now better prepared to deal with seasonal or pandemic flu?
  • What new discoveries or inventions could make the biggest difference in the future?

About this resource

This resource was first published in ‘Influenza special issue’ in October 2009 and reviewed and updated in January 2015.

Topics:
Statistics and maths, Microbiology, Genetics and genomics, Health, infection and disease, History
Issue:
Influenza special issue
Education levels:
16–19, Continuing professional development