Vaccination against influenza: role and limitations in pandemic intervention plans

Abstract

Influenza pandemics occur periodically and the subtype of the next pandemic strain cannot be predicted. Vaccination remains a critical intervention during pandemics, but current production technology requires several months to develop sufficient vaccine to meet anticipated worldwide need. Candidate prepandemic vaccines for use in population priming or rapid deployment during an epidemic are in development but are subtype specific and logistical obstacles to timely distribution exist. Intensive research is underway to identify a universal vaccine, providing protection against all known influenza strains based on shared epitopes. Vaccine access is expected to be limited during early response to a pandemic, necessitating ethical vaccine distribution plans for within-country and global allocation. Mass vaccination plans must be in place prior to an event to ensure appropriate infrastructures are in place. Carefully crafted education campaigns regarding pandemic vaccine safety and efficacy should aid in maximizing pandemic vaccine uptake during a future event.

Bioinformatic prediction of epitopes in the Emy162 antigen of Echinococcus multilocularis

“…Echinococcosis is severely harmful to human health, the development of the social economy and animal husbandry (5). It has a high ten-year mortality rate, and is regarded as one of the most lethal helminthic infections (6–9).…”

A phase II study of an investigational tetravalent influenza vaccine formulation combining MF59®

“…However, there are numerous logistical concerns, including the timely production, distribution, and administration of vaccine. 6,7 Therefore, strategies to ensure preparedness for a future pandemic include the development of pre-pandemic vaccines able to prime an immunologically naive population for later boosting, should a pandemic occur. In an immunologically naive individual, at least two doses of A/H5N1 vaccine with high antigen content are needed to elicit adequate, seroprotective immune responses.…”

Extrapolating theoretical efficacy of inactivated influenza A/H5N1 virus vaccine from human immunogenicity studies

“…Although trial arms with antigen dosages of 90 mcg did not produce markedly different theoretical efficacies from trial arms with MF59 adjuvanted antigens, it may be unrealistic to use an antigen dosage of 90 mcg, because vaccine supplies are limited [30]. Among these arms, the highest theoretical vaccine efficacy was achieved in the trial arm where the second dose was given after 180 days, suggesting that a prepandemic priming vaccination strategy could be highly beneficial.…”