Re:Adverse events following influenza vaccination in Australia--should we be surprised?
"Influenza vaccines in children: more harm than good?"
National authorities worldwide promote influenza vaccines, arguing
they are not just effective, but extremely safe. The US NIAID director
claimed that "the track record for serious adverse events is very good.
It's very, very, very rare that you ever see anything that's associated
with the vaccine that's a serious event". (1)
There is now abundant evidence that such optimism is misguided. In
Australia last year, one febrile convulsion occurred for every 100 to 200
young children vaccinated with CSL's influenza vaccine (2,3,4). Now in
the US there have been similar concerns. A recent analysis of the
American experience reported a rate of 60 seizures per 100,000 influenza
vaccinations when given together with conjugated pneumococcal vaccine (5).
However this is likely to under-estimate the true rate. One post-marketing
vaccine safety study showed reports of febrile seizures admitted to
hospital, was 5 times lower with passive surveillance (6).
US authorities describe febrile convulsions as "very frightening for
parents," but "fairly common" and self-limiting (7). Yet febrile
convulsions are the cause of emergency room visits, and in Australia's
recent experience, 38% of children with febrile convulsions following
vaccination (19 of 56) were admitted to hospital (4).
Vaccine policies must ensure they are doing more good than harm.
Vaccine must cause far fewer serious adverse events compared to what the
disease would have caused in the vaccine's absence. Evidence suggests
this is not the case with influenza. In Australia in 2009, during winter
when young children (0-4 years) were first hit with the new H1N1 strain,
the admission rate for influenza was 57 per 100,000 (8). In the US, CDC
says that influenza results in hospitalization for approximately 20 per
100,000 children aged 2 to 5 years (9), but vaccine-induced febrile
convulsions resulting in hospitalization in US young children, likely
occurred at a rate of 114 per 100,000 children vaccinated . According to
the FDA, a "serious adverse event" is defined as hospitalization that
results from a vaccine adverse event (10). Thus vaccinating young children
without risk factors likely caused more serious adverse events than
disease from the new "pandemic" itself.
There is poor safety data available for other serious adverse events
that might occur in young children in addition to febrile seizures (11).
Evidence from systematic reviews show evidence of data suppression of
vaccine-associated harms to small children by some pharmaceutical
companies (12). Other reports suggest that influenza vaccines put children
at higher risk of future influenza infections compared to acquiring
natural infection (original antigenic sin) (13). In older children,
unexpected adverse events such as narcolepsy have been reported from at
least 12 countries (14). In Canada previous immunisation with seasonal
influenza vaccine doubled your risk of being infected with "swine flu"
In 2005, when a new study demonstrated that influenza vaccines were
not saving elderly lives (16), many argued that this underscored the
importance of vaccinating more children (17). Yet we have no evidence
demonstrating that children are benefiting from this strategy but do have
evidence that these vaccines are hospitalizing children. The recent H1N1
"pandemic" and our immunisation response show that in children we likely
caused more harm than good. Public health authorities should not continue
to recommend (as in the US), that all children receive routine influenza
vaccine until we have much better safety and efficacy data.
1. How Safe is the Flu Vaccine? 2009 [cited 2010 May 8]. Available
2. Collignon P, Doshi P, Jefferson T. Adverse events following
influenza vaccination in Australia--should we be surprised? (7 May 2010)
3. TGA. Investigation into febrile reactions in young children
following 2010 seasonal trivalent influenza vaccination. Updated 24
September 2010. http://bit.ly/e3bPbp
4. Kelly H, Carcione D, Dowse G, Effler P. Quantifying benefits and
risks of vaccinating Australian children aged six months to four years
with trivalent inactivated seasonal influenza vaccine in 2010. Euro
5. Small Seizure Risk With Flu, Pneumococcal Vaccines CDC Says
Getting the Vaccines Together Raises Risk of Febrile Seizure in Kids By
Daniel J. DeNoon WebMD Health News.
6. Farrington P, Pugh S, Colville A, et al. A new method for active
surveillance of adverse events from diphtheria/tetanus/pertussis and
measles/mumps/rubella vaccines. Lancet 1995;345:567-9.
7. CDC. Febrile Seizures Following Childhood Vaccinations, Including
Influenza Vaccination. (October 12, 2010) Available online:
8. New South Wales public health network. Progression and impact of
the first winter wave of the 2009 pandemic H1N1 influenza in New
SouthWales, Australia. Euro Surveill. 2009;14(42):pii=19365.
9. Fiore AE, Uyeki TM, Broder K, Finelli L, Euler GL, Singleton JA,
et al. Prevention and control of influenza with vaccines: recommendations
of the Advisory Committee on Immunization Practices (ACIP), 2010. MMWR
Recomm Rep. 2010 Aug 6;59(RR-8):1-62.
10. FDA definition of serious adverse events.
11. Jefferson T, Rivetti A, Harnden AR, Di Pietrantonj C, Demicheli
V. Vaccines for preventing influenza in healthy children. Cochrane
Database of Systematic Reviews 2008, Issue 2. Art. No.: CD004879. DOI:
12. Jefferson T, Smith S, Demicheli V, Harnden A, Rivetti A. Safety
of influenza vaccines in children. Lancet. 2005 Sep 3;366(9488):803-804.
13. Morens DM, Burke DS, Halstead SB. The wages of original antigenic
sin. Emerg Infect Dis. 2010 June.
14. Increased risk of narcolepsy observed among children and
adolescents vaccinated with PandemrixR.
15. Skowronski DM, De Serres G, Crowcroft NS, Janjua NZ et al.
Canadian SAVOIR Team. Association between the 2008-09 seasonal influenza
vaccine and pandemic H1N1 illness during Spring-Summer 2009: four
observational studies from Canada. PLoS Med. 2010 Apr 6;7(4):e1000258.
16. Simonsen L, Reichert TA, Viboud C, Blackwelder WC, Taylor RJ,
Miller MA. Impact of Influenza Vaccination on Seasonal Mortality in the US
Elderly Population. Arch Intern Med. 2005 Feb 14;165(3):265-272.
17. Cohen J. INFLUENZA: Study Questions the Benefits of Vaccinating
the Elderly. Science. 2005 2;307(5712):1026-1026.
Infectious Diseases Physician and Microbiologist
Director Infectious Diseases Unit and Microbiology Department, The
Professor, School of Clinical Medicine, Australian National University.
PO Box 11, Woden, ACT. 2607. Australia
Program in History, Anthropology, Science, Technology and Society,
Massachusetts Institute of Technology, Cambridge, MA 02139 USA.
Coordinator, Cochrane Vaccines Field, Rome, Italy.
Competing interests: TJ is an author of the relevant Cochrane reviews.All others no competing interests