Research over the course of 8 seasons (1999-2007) shows a threefold increased risk of hospitalization in subjects who did get the trivalent inactivated flu vaccine, vs. unvaccinated subjects.
During these 8 seasons strain A(H3N2) was wrongly guessed 5 times; strain A(H1N1) and B – 4 times.
Seasonal influenza vaccination increased the risk of swine flu infection by 2.5 times among children in Canada in 2009. These results were confirmed in five other studies. More: .
In a ferret study part of the animals received a 2008-09 influenza vaccine and then infected with swine influenza; the other part received a placebo injection. As shown by to subsequent observations, the vaccinated ferrets suffered a more severe disease compared to the unvaccinated ferrets.
Vaccination against influenza during pregnancy increases the risk of miscarriage in the next 28 days by 2 times.
Among women who received an influenza vaccine in the previous influenza season, the risk of miscarriage was 7.7 times higher.
A Vaccine Adverse Event Reporting System (VAERS) study.
During a two-vaccine 2009-10 season, when pregnant women were vaccinated against common flu and swine flu, the risk of fetal losses was 11 times higher than during the 2008-09 season, and 6 times higher than during the 2010-11 season.
Three studies are usually used to prove the flu vaccine safety for pregnant women.
First study involved 56, second – 180 women. Both these studies used ‘no Thimerosal’ vaccines.
A third study was conducted among 2291 pregnant women but fetal losses were not included in the analysis.
It is thought that vaccines may cause a fetal loss in 1.9 cases per million of vaccinated women. However this data does not take into consideration that VAERS registers only an insignificant number of vaccine side effects.
Risk of narcolepsy in vaccinated against swine flu in 2009 was increased by 17 times. In another study the risk was increased 4-9 times. Third study showed 14-16 times narcolepsy risk increase.
A similar Swedish study found increased psychiatric comorbidity in children and adolescents with narcolepsy.
A possible explanation of this phenomenon may be that the human antibodies to nucleoprotein cross-react with human hypocretin receptor.