Established
Safety Surveillance for Smallpox Vaccine
General
Steps to Establishing Vaccine Safety Surveillance (22:V7:4)
If there is
no system in place for monitoring adverse events that could handle
the addition of surveillance for smallpox, VIG, and Cidofovir,
the following activities should be taken:
- Clarify the
roles of the national regulatory authority and public health
epidemiology and agree on objectives for the system.
- Identify
the resources available and needed and establish political commitment
to immunization safety surveillance.
- Appoint or
designate regional and/or national assessors for immunization
safety.
- Establish
an expert panel on immunization safety.
- Develop and
disseminate a list of events to be reported and their case definitions;
a standard investigation procedure; and report and investigation
forms.
- Designate
and train staff to prepare the reports, complete the report forms,
investigate adverse events, and conduct analyses of the data
as appropriate.
- Inform all
healthcare workers and clinicians of the need to report an adverse
event immediately and clarify which ones should be reported.
- Consider
the establishment of a compensation scheme for specified adverse
events.
What
to Report
Reportable adverse
events must include any deaths or serious adverse events believed
by the public or healthcare workers to be caused by immunization.
Some events like abscess, toxic shock syndrome, and sepsis, are
indicators of program error and need to be monitored at a minimum
to identify and correct program errors. In addition, providers
must be encouraged to report even if the causality of the adverse
event is uncertain (i.e., temporal association is sufficient for
reporting).
More information
can be found in the World Health Organization guidelines on “Immunization
Safety Surveillance.” (You need Adobe Acrobat Reader
to view this link.)

Current General
Vaccine Safety Infrastructure in the United States
VAERS (The Vaccine
Adverse Event Reporting System) is the national surveillance system
for adverse events following the administration of U.S. licensed
vaccines. VAERS is administered by the CDC and the Food and Drug
Administration (FDA). VAERS data is routinely analyzed by the CDC
and the FDA to identify new or rare vaccine side effects, increases
in rates of known side effects, associations with specific vaccine
lots and patient risk factors. All smallpox adverse event reports
are also delivered to this system.

The VAERS Reporting
Form (22:V7:10) can be downloaded from the
internet for physician or patient access and reporting. The internet
site address for the form is https://secure.vaers.org/VaersDataEntryintro.htm.
The form is designed to obtain basic information about the adverse
event and its management. Additional follow-up is done to determine
long-term sequelae.
VAERS
Role in Smallpox Vaccine Response (22:V7:11)
The VAERS system
is useful as a mechanism for monitoring smallpox vaccine adverse
events because it’s national and known to healthcare providers.
It allows the CDC to get an indication of what is occurring with
the vaccine. However, since it is simply a gathering point of information,
it cannot determine whether or not a vaccine caused the adverse
events.
While VAERS
provides useful information on vaccine safety, the data are somewhat
limited. Judgments about causality (whether the vaccine was truly
responsible for an adverse event) cannot be made from VAERS reports
because of incomplete information. VAERS reports often lack important
information such as laboratory results. As a result, researchers
have turned more recently to large-linked databases (LLDBs) in
order to further study vaccine safety. LLDBs provide scientists
with access to the complete medical records of millions of individuals
receiving vaccines (all identifying information is deleted to protect
the confidentiality of the patient).
Role of the
Institute of Medicine (22:V7:12)
As concerns
about vaccine safety or a particular AE association are raised
by VAERS data or by other studies, the Institute of Medicine can
convene expert committees to review the hypotheses and supporting
information to determine their significance to public health. The
mission of the Institute of Medicine is to advance and disseminate
scientific knowledge to improve human health. The Institute provides
objective, timely, authoritative information and advice concerning
health and science policy to government, the corporate sector,
the professions and the public. The web address for the Institute
of Medicine is: http://www.iom.edu/.
Clinical
Immunization Safety Assessment (CISA) Network (22:V7:13)
The Clinical
Immunization Safety Assessment Network, or CISA, was established
to provide clinical evaluation of the data collected by VAERS in
order to help determine whether or not a particular vaccine caused
an adverse event. Many of the top academic centers in the U.S.
are part of this network. CISA is composed of academic centers
of excellence (4) in partnership with CDC serving as a source of
clinical expertise in adverse events following immunization. The
four academic centers are: Johns Hopkins with University of Maryland,
Boston Medical Center, Kaiser Research Institute Foundation with
Stanford University and Vanderbilt University and New York Presbyterian-Columbia.
Vaccine Safety
Datalink
The gaps that
exist in the scientific knowledge of rare vaccine side effects
prompted the CDC to develop the Vaccine Safety Datalink (VSD) project
in 1990. This project involves partnerships with seven large health
maintenance organizations (HMOs) to continually monitor vaccine
safety. VSD is an example of a large-linked database (LLDB) and
includes information on more than six million people. All vaccines
administered within the study population are recorded. Available
data include vaccine type, date of vaccination, concurrent vaccinations
(those given during the same visit), the manufacturer, lot number,
and injection site. Medical records are then monitored for potential
adverse events resulting from immunization. The VSD project allows
for planned vaccine safety studies as well as timely investigations
of hypotheses. The web address for the home page for the Vaccine
Safety Datalink is: http://www.cdc.gov/nip/vacsafe/vsd/default.htm.
Importance
of Monitoring Smallpox Vaccine Safety (22:V7:16)
Although we
have a great deal of information already on the expected adverse
events associated with smallpox vaccine, monitoring for these and
other adverse events is still essential (in both a pre- and post-
event vaccination campaign). Several issues arise that support
the need for organized monitoring for adverse events:
- Smallpox
vaccination hasn’t been used on a large scale in quite
some time, therefore, primary vaccine recipient populations will
generally be older than during the eradication period.
- More people
exist today with disease or medication altered immune systems
than existed when the vaccine was used on a wide-scale.
- Because the
make-up and health status of today’s population is different
than previously, while we can make intelligent guesses as to
what to expect in terms of adverse events, we really do not have
a modern day safety profile.
In addition,
it is extremely important to actively track serious vaccine adverse
events that may require specialized and/or limited treatment resources
in order to gauge and address those resource needs to support vaccination.
|