AC 2005 Vol-1.pdf - Cecmed - Infomed

119 Trabajo experimental
Collaborative studies
We have been involved in two
collaborative studies. We developed a
collaborative study concerning of the in
vitro potency test for Hepatitis B vaccine
in order to demonstrate that our test could
monitor the manufacturer’s results. We
sent to the Cuban manufacturer (CIGB)
blinded samples of 10 batches and
evaluated whether there was a significant
correlation between both methods. For in
vitro potency test CIGB and our lab used a
method based on the same principle (a
previous neutralization step and a
subsequent ELISA for determining anti-
HbsAg antibodies), but CIGB used their
own reagents [7] meanwhile we used anti-
HbsAg Hepanostika kit from Organon
Teknika [5].
The other collaborative study was a part of
the study (Phase 2) for the characterization
of the candidate WHO reference panel for
Hepatitis B surface antigen (HbsAg). The
Phase 1was performed by the Working
Group on Hepatitis and HIV Diagnostic
Kits by calibration of the most
concentrated panel member against for the
First International Standard for HbsAg
(NIBSC Code 80/549). The aim of this
study was to characterize the reference
panel in a wide range of HbsAg detection
kits, which are in use around the world.
The panel members sent by NIBSC were
reconstituted in 1 mL distilled water as
described in the study Protocol. These
members were treated as typical test
samples and assayed in duplicate as
recommended by the manufacturer [7].
The testing was repeated on three
separated days. Raw data were returned to
NIBSC for processing.
Control Charts
We established a Control Chart for the
Hepatitis B vaccine standard (a Regional
Standard) used for in vitro potency test.
We selected ED 50 of the standard as a
parameter for monitoring the performance
of the potency. The Control Chart was
built using Microsoft Excel and we
analysed the results following the Finney’s
method [8].
Results and Discussion
The implementation of a Quality
Assurance Program is a vital step to ensure
the reliability of test results.
As shown in Tables 1, 2 and 3, the
evaluations performed were successful
because all the criteria of competence were
fulfilled. For Polio test, the difference
between replicates for each vaccine
component (including thermostability) was
no longer than 0.5log10 whereas for
Hepatitis B test the variability between
analysts was lower than 20%
(CV=11.05%). In both cases, the results
were within the expected range.
The impact of training and data review on
the quality control testing is shown in
Table 4. For Polio and Hepatitis B
vaccines, we have performed 111 potency
tests so far, and only the 1.8 % have
resulted non-valid tests.
According to these results, it’s evident
training and data review is a powerful
method for monitoring the operator
performances and assuring the lab results.
As shown in Table 5 we have performed
15 self-inspections, including routine and
follow up inspections. Analysis of Table 5
shows successful compliance of corrective
actions for the majority of Quality System
activities. In the case of equipment, the
lower percent of compliance is due to the
lack of resources to deal with the
deviations detected. In general, this result
is evidence of the capacity of selfinspections
to identify deviations and take
corrective actions. Self - inspections has