Pre-Pandemic Vaccination Approach Could Mitigate Worst Effects of Pandemic Flu

Strategic Insights -

A six-month time lag is a critical window for the production of effective vaccines in the event of a pandemic flu outbreak, warns a research study published in the Proceedings of the National Academy of Sciences of the USA. The study, led by Dr. Iain Stephenson, Consultant in Infectious Diseases at the Leicester Royal Infirmary and a Clinical Senior Lecturer at the University of Leicester, proposes the development of a pre-pandemic vaccine to mitigate the worst effects of pandemic flu. This approach would involve stockpiling vaccine or immunizing people with vaccine prepared in advance to protect them before a future pandemic.

Key Takeaways:

  • The study highlights the six-month time lag between the emergence of a new influenza strain and the production of effective vaccines, making pre-pandemic vaccination a critical strategy to protect the population.
  • The pre-pandemic vaccine approach involves stockpiling vaccine or immunizing people with vaccine prepared in advance to generate long-lasting memory cells that can be rapidly boosted by a single dose of vaccine when needed.
  • The study demonstrates that people who received H5 vaccine between 1999 and 2001 responded very well to a single dose of a newer H5 vaccine, showing rapid protective responses within 7 days of the repeat vaccine.
  • Those who had not been previously vaccinated with H5 vaccine required 2 doses of vaccine and got good antibody responses up to 6 weeks after the first dose.
  • The study highlights the importance of developing a pre-pandemic vaccine that can provide cross-protection against multiple strains of H5N1 virus.
  • Dr. Stephenson and his team conducted a study comparing the effect of a single H5 bird flu vaccine dose to people who had been vaccinated with an H5 vaccine previously with people who had not previously received vaccine.
  • The study recruited subjects at the University of Leicester or University Hospitals of Leicester and involved a total of 303 participants.
  • A pre-pandemic vaccine needs to give cross-protection to as many H5 strains as possible, given the uncertainty of which strain will cause the pandemic.

Statistics:

  • Six months is the critical window for the production of effective vaccines in the event of a pandemic flu outbreak.
  • 303 participants were recruited for the study.
  • 1999-2001 is the period during which study participants received their first H5 vaccine.
  • A single dose of H5 vaccine triggered rapid protective responses within 7 days of vaccination in those who had received H5 vaccine previously.
  • Those who had not received H5 vaccine previously required 2 doses of vaccine for effective immunity.
  • 7 days is the timeframe within which subjects who received H5 vaccine previously showed rapid protective responses.
  • 6 weeks is the timeframe within which antibody responses were observed in those who had not received H5 vaccine previously.

Sources:

  • Dr. Iain Stephenson, Consultant in Infectious Diseases at the Leicester Royal Infirmary and a Clinical Senior Lecturer at the University of Leicester.
  • University of Leicester.
  • University Hospitals of Leicester NHS Trust.
  • PNAS- Proceedings of the National Academy of Sciences of the USA.