Adjuvants are agents that are sometimes added to a vaccine to make it more effective. There are no adjuvants (such as squalene) in either the 2009 H1N1 or seasonal flu shot used in the United States.
In 1976, an earlier type of swine flu vaccine was associated with cases of a severe paralytic illness called Guillain-Barre Syndrome (GBS) at a rate of approximately 1 case of GBS per 100,000 persons vaccinated. Some studies done since 1976 have shown a small risk of GBS in persons who received the seasonal influenza vaccine. This risk is estimated to be no more than 1 case of GBS per 1 million persons vaccinated.
Without adjuvant, two doses are required for a robust antibody response
BCB, CFR, JD, DC, RR, PRD, and DTO are employees and shareholders in Novartis Vaccines and Diagnostics, which manufactures influenza vaccines and adjuvants, including Focetria® and MF59.
The 1st wave of H1N1pdm in summer 2009 can be characterized as mild, relative to the mortality impact of severe winter-seasonal influenza epidemics.
a mild summer wave with elevated mortality in young adults resembles the pattern of the 1918 pandemic, in which a first spring wave in the US [32] or summer wave in Europe [33] was associated with unusual deaths in young adults.The subsequent catastrophic wave in autumn 1918 killed about 2% of the population world-wide
The early phases of recognition of emerging infections almost always show a high case fatality rate due to the dramatic ascertainment of cases and the unknown extent of infections that have already occurred.Media and public health alarm bells are frequently sounded until there is a clearer understanding of the degree of background infections are measured as well as transmission rates
an autumn-winter pandemic wave of pH1N1 with comparable severity per case could lead to a number of deaths in the range from considerably below that associated with seasonal influenza to slightly higher, but with greatest impact in young children and non-elderly adults