Investing in Immunity: Prepandemic Immunization to Combat Future Influenza Pandemics

Abstract

We are unlikely, with current technologies, to have sufficient pandemic influenza vaccine ready in time to impact the first wave of the next pandemic. Emerging data show that prior immunization with an immunologically distinct hemagglutinin of the same subtype offers the potential to "prime" recipients for rapid protection with a booster dose, years later, of a vaccine then manufactured to match the pandemic strain. This article proposes making prepandemic priming vaccine(s) available for voluntary use, particularly to those at high risk of early occupational exposure, such as first responders and healthcare workers, and to others maintaining critical infrastructure. In addition to providing faster protection and potentially reducing social disruption, being able, early in a pandemic, to immunize those who had received prepandemic vaccine with one dose of the pandemic vaccine, rather than the 2 doses typically required, would reduce the total doses of pandemic vaccine then needed, extending vaccine supplies.

Lessons From Influenza Pandemics of the Last 100 Years

“…New technologies, such as a universal vaccine, may eventually change this situation but not in the near term. The prepandemic use of vaccines containing known potential pandemic viruses, often with adjuvants, has been proposed, but there are significant uncertainties in choosing what viruses might go into such a vaccine or for taking the inherent risks [61,62].…”

Editorial Commentary: Is Prepandemic Vaccination a Wise Investment?

“…In an intriguing and thoughtful article in this issue of Clinical Infectious Diseases [3], Dr Goodman suggests that rather than stockpiling such vaccines in storage, it might be better to stockpile immunity in recipients by employing the vaccines in advance of a pandemic. In this strategy, targeted groups would be immunized with pandemic vaccines in advance of a pandemic, simplifying the logistics of responding if and when such an event did occur.…”

“…As Goodman [3] and others [14] have pointed out, one of the most difficult questions that remains unanswered is how to predict the priming effect and assess its duration. Mechanistic studies in humans are difficult because of the limited sites that can be sampled.…”