Discussion:
Varicella-zona Virus reactivation in immunocompetent cases
infected with Severe Acute Respiratoy Syndrome Coronavirus 2 (SARS-Cov2)
has been published [4, 5]. This association can be explained by
cytokine release and lymphopenia during the COVID-19 [6]. A fair
number of Herpes zoster cases developing after the administration of
mRNA and inactivated COVID-19 vaccines have been reported in the
litterature [2, 3, 7, 8]. The majority of the cases developed after
the first dose versus the second dose of the vaccine. However, reported
cases of reactivation of VZV after viral vector COVID-19 vaccines were
few [9].
Most commonly reported adverse effects of COVID-19 vaccine were short
term, mild to moderate pain in injection site, fatigue, fever and
headache, but other side effects remain unknown [10]. The short
delay of onset after vaccination and the occurrence in immunocompetent
patients suggests a strong link between COVID-19 vaccine and herpes
zoster emergence. The exact mechanism remain unsolved, but it is
possible that the VZV reactivation is one of the side effects of the
novel vaccination. A case control study of Alhasawi A et al ,
enrolling 186 patients, showed that the COVID-19 vaccination had
significant statistical association with herpes zoster (adjusted matched
odds ratio=4.87, 95% confidence interval : 2.40 – 9.89,p <0.001) [11].
These vaccines don’t cause lymphompenia or cytokine release, but they
can induce an immunomodulaion that may be responsible for herpes zoster
[12]. Another theory is suggesting similarities with the immune
reconstitution syndrome (IRS) wich is a paradoxical worsening of a
pre-existing infection seen in immunocompromised HIV patients, following
the initiation of antiretroviral therapy [13].
The ophtalmic division of the trigeminal nerve is the most involved
branch in herpes zoster, while the maxillary nerve, the second division
wich is affected in our case, is the least frequently affected and
rarely causes ocular injury [14]. In the study of Psichogiou etal , there were two cases of herpes zoster of the second division
of the trigeminal nerve following mRNA COVID-19 vaccine [13].