Immunogenicity, Boostability, and Sustainability of the Immune Response after Vaccination against Influenza A Virus (H1N1) 2009 in a Healthy Population

Persistence and avidity maturation of antibodies to A(H1N1)pdm09 in healthcare workers following repeated annual vaccinations

“…Studies suggest that antibody responses in previously vaccinated subjects were lower than in subjects with no prior vaccination [12,39]. This may be due to residual protection resulting in attenuated antibody responses [45].…”

“…These inferior responses may be attributed to lack of adjuvant in the vaccines administered in these studies. In the Netherlands, 80% of HCWs achieved protective HI titers with MF59 adjuvanted vaccine [39]. The oil-in-water emulsion adjuvants, MF59 and AS03, are known to enhance antibody responses after H1N1 and H5N1 vaccination and also allow considerable dose sparing [40][41][42][43].…”

Persistence of Immunogenicity of a Monovalent Influenza Virus A/H1N1 2009 Vaccine in Healthy Volunteers

“…In fact, the World Health Organization (WHO) has announced that H1N1 virus is one of the viruses recommended for seasonal influenza vaccines in the Northern Hemisphere in 2011 to 2012 (28). A recent study also indicated that a booster dose may confer additional benefits for the elderly (9). There was no participant with flu symptoms, as determined by follow-up monthly surveillance phone calls.…”

“…Global H1N1 vaccination was carried out after much research on immunogenicity and safety (5,7,14,16,17,19,20,30). However, data on the long-term immunity conferred by and clinical outcomes of vaccination are lacking (9).…”

Medical Surveillance Monthly Report. Volume 21, Number 6

“…Th is, in turn, leads to greater experience with, or exposure to, infl uenza vaccines, which might lead to a diminished antibody response and potentially diminished VE. [14][15][16][17] In addition, the fact that the U.S. military starts vaccinating for infl uenza as early as August each year raises the possibility that individuals vaccinated several months prior to the infl uenza season peak, typically in January or February, might be left unprotected due to waning immunity when the risk for infection is highest. Additional research aimed at understanding the impact of long vaccination histories (i.e., many vaccinations over many years) and regarding the duration of protection of infl uenza vaccines is needed to further elucidate these fi ndings.…”