Intended for healthcare professionals

Rapid response to:

Letters Child influenza vaccination

Ramifications of adverse events in children in Australia

BMJ 2010; 340 doi: (Published 09 June 2010) Cite this as: BMJ 2010;340:c2994

Rapid Response:

Underreporting Vaccine Adverse Events

Peter Collignon and his colleagues do not exaggerate the problem of
event underreporting. VAERS (Vaccine Adverse Events Reporting System) is
the voluntary system used in the U.S. to signal vaccine side effects.

the 18-year period from 1990 through 2007 just 88 cases of Kawasaki
Disease in children under 5 were reported to VAERS. During the same
about 88 million U.S. children passed through the 0-5 age group;
consequently the incidence rate reported to VAERS was 0.10 KD cases per
100,000 person-years. (Pediatr Infect Dis J 28:943, 2009) From 1988 to
2006 the published KD incidence for U.S. children under 5 rose from 11.0
20.8 per 100,000 person-years. (Pediatrics 111:448, 2003. Pediatrics
112:495, 2003. Pediatr Infect Dis J 29:483, 2010) Even for infants 3-6
months old, when suspicion for vaccine adverse effects should be
high, KD incidence as reported to VAERS was 0.11 while published
background rates were 23.1 (2000) and 24.6 (2006); fewer than 1 in 200 KD
cases were reported to VAERS.

It is bewildering, therefore,
to learn
that FDA and CDC officials used VAERS data to dismiss a placebo-controlled

trial that found a 5-fold KD risk associated with RotaTeq--RR=4.9; 95% CI
0.6, 239. (Pediatr Infect Dis J 28:943, 2009. 6/15/07.
) If confirmed by a larger trial, the KD
associated with RotaTeq would translate to an extra 4000 U.S. cases
in young children.

I know that this discussion began with
convulsions in young children given seasonal flu vaccine, but the problems

with voluntary reporting systems, underreporting of adverse events and the

way the data are used by public health officials and the vaccine industry
to other vaccines and other serious clinical problems. How can public
officials rely on a system that reports fewer than 1% of adverse effects?
can they dismiss placebo-controlled trials that raise serious
possibilities of
vaccine-caused illness?

Competing interests:
None declared

Competing interests: No competing interests

16 July 2010
Allan S. Cunningham
Retired pediatrician
Cooperstown NY 13326