Varicella vaccination recommended for healthcare workers in
the United Kingdom
The Chief Medical Officer for England has recently published
a new varicella vaccination policy for healthcare workers (HCW) in the United
Kingdom (UK), which recommends vaccination for HCWs who have no definite history
of the disease and are seronegative (1). These recommendations are for HCWs
who have any direct contact with patients and include paramedic (e.g. ambulance
drivers) and ancillary staff (e.g. cleaners). A prioritisation of these staff
for vaccination has also been recommended with precedence given to those working
with immunocompromised individuals (e.g. in oncology and transplant wards).
Vaccinated HCWs who develop symptoms are recommended to report to occupational
health departments to avoid the possibility of secondary transmission.
Varicella vaccination is not recommended for listed contraindications that
include pregnancy. An important risk for HCWs is the inadvertent vaccination
of pregnant individuals. In the United States, surveillance of inadvertent
immunisation of pregnant women with the Oka/Merck strain (VARIVAX)
has not identified any specific risk to the foetus (2). The establishment
of such a register, to monitor possible sequelae following such an event,
is a feature of the recent recommendations in the (UK).
The UK is one of the first European countries to publish official recommendations
for varicella vaccination. A survey of the immunisation policies amongst
countries participating in the European Sero-Epidemiological Network (ESEN2,
has recently been undertaken. A wide variety of different policies for varicella
vaccination have been implemented or are being considered amongst the participating
countries. The immunisation of seronegative professional HCWs has (or is)
being considered by only a handful of other European countries. Interestingly,
in some countries, a recommendation to vaccinate all seronegative individuals
involved in the care of children is also being considered.
Vaccination against varicella has been recommended in the United States
for all susceptible people aged 12 months or older since 1995 (3). Of those
countries participating in ESEN2, only one country has introduced (in 2001)
mass vaccination against VZV targeted at a similar age group as the US vaccination.
However, concerns have been raised of the effectiveness of such a strategy,
as it may result in an increase in cases of zoster disease, because of the
lack of boosting of immune responses in older individuals (4,5). Furthermore,
a mass vaccination campaign with a suboptimum coverage could result in an
increase in the average age of infection to those ages in which the disease
and its sequelae are more severe (4).