Background:
Vaccination of children against VZV has
been included in the recommendations of the “permanent
committee of vaccination” (STIKO; Ständige Impfkommission
of the Robert Koch Institute, Berlin, Germany) in July 2004.
Due to this recommendation the medical practitioner and
the laboratories will be confronted with the problem of
serologic non-responders or loss of humoral immunity more
frequently.
Patients and Methods:
Here we report the case of a
Varicella Zoster Virus (VZV) vaccinee, who lost detectable
VZV antibodies although she had a persisting VZV specific
CD4 cellular immune response. We compare these parameters
to the VZV specific CD4 T cell responses of VZV seronegative
and seropositive healthy persons, as well as patients with
VZV disease.
Results:
VZV specific CD4 frequencies of VZV antibody
seronegative persons remained on the average below 0.1%
(median 0.04%, ± SD 0.03, range 0.01–0.08%) and were
significantly lower than VZV specific frequencies of seropositive
healthy persons (median 0.3%, ± SD 0.24, range
0.06–0.81%; Mann-Whitney U-test p = 0.001). The samples
of patients with VZV associated disease showed an even
higher median level of VZV specific CD4 cell response than
the VZV seropositive healthy persons (median 1.04%, ± SD
1.06, range 0.51–2.92%, Mann-Whitney U-test p = 0.008).
The VZV specific immune response of the health care worker
directly after vaccination was comparable to the VZV specific
immunity in VZV seropositive healthy adults. Despite
serological reconversion 1.5 years later the VZV specific CD4
response still remained measurable and positive.
Conclusion:
The new general VZV vaccination recommendation
for children in Germany will probably increase the
number of persons that will be seronegative after vaccination.
To gain more information concerning the absence of
seroconversion or the loss of immunity, it will be necessary
to focus future post-VZV vaccination immunity studies not
only on serologic testing but also on the measuring of the
cell mediated immunity.