Sao Paulo Med J. 2014; 132(4):255 255
Vaccines for preventing
herpes zoster in older adults
Ana M. Z. Gagliardi, Brenda Nazaré Gomes Silva,
Maria Regina Torloni, Bernardo Garcia de Oliveira Soares
The independent commentary was written by Luiz
Eugênio Garcez Leme
BACKGROUND: Herpes zoster or, as it is commonly called, ‘shingles’
is a neurocutaneous disease characterised by the reactivation of vari-
cella zoster virus (VZV), the virus that causes chickenpox, which is la-
tent in the dorsal spinal ganglia when immunity to VZV declines. It is
an extremely painful condition which can often last for many weeks or
months, impairing the patient’s quality of life. The natural aging process
is associated with a reduction of cellular immunity which predisposes
to herpes zoster. Vaccination with an attenuated form of VZV activates
specific T cell production, therefore avoiding viral reactivation. A herpes
zoster vaccine with an active virus has been approved for clinical use
among older adults by the Food and Drug Administration and has been
tested in large populations.
OBJECTIVE: To evaluate the effectiveness and safety of vaccination for
preventing herpes zoster in older adults.
Search methods: We searched the following sources for relevant studies:
CENTRAL 2012, Issue 7, MEDLINE (1948 to July week 1, 2012), EMBASE
(2010 to July 2012), LILACS (1982 to July 2012) and CINAHL (1981 to July
2012). We also reviewed reference lists of identified trials and reviews
for additional studies.
Selection criteria: Randomised controlled trials (RCTs) or quasi-RCTs
comparing zoster vaccine with placebo or no vaccine, to prevent
herpes zoster in older adults (mean age > 60 years).
Data collection and analysis: Two review authors independently
collected and analysed data using a data extraction form. They also
carried out an assessment of risk of bias.
MAIN RESULTS: We identified eight RCTs with a total of 52,269 partici-
pants. Three studies were classified at low risk of bias. The main outcomes
on effectiveness and safety were extracted from one clinical trial with a
low risk of bias. Four studies compared zoster vaccine versus placebo;
one study compared high-potency zoster vaccine versus low-potency
zoster vaccine; one study compared refrigerated zoster vaccine versus
frozen zoster vaccine; one study compared live zoster vaccine versus in-
activated zoster vaccine and one study compared zoster vaccine versus
pneumococcal polysaccharide vaccine (pneumo 23).
Confirmed cases of herpes zoster were less frequent in patients who
received the vaccine than in those who received a placebo: risk ratio
(RR) 0.49 (95% confidence interval (CI) 0.43 to 0.56), with a risk dif-
ference (RD) of 2%, and number needed to treat to benefit (NNTB)
of 50. Analyses according to age groups indicated a greater benefit
in participants aged 60 to 69 years, RR 0.36 (95% CI 0.30 to 0.45) and
in participants aged 70 years and over, RR 0.63 (95% CI 0.53 to 0.75).
Vaccine-related systemic adverse effects were more frequent in the
vaccinated group (RR 1.29, 95% CI 1.05 to 1.57, number needed to
treat to harm (NNTH) = 100). The pooled data risk ratio for adverse ef-
fects for participants with one or more inoculation site adverse effect
was RR 4.51 (95% CI 2.35 to 8.68), and the NNTH was 2.8 (95% CI 2.3 to
3.4). Side effects were more frequent in younger (60 to 69 years) than
in older (70 years and over) participants.
AUTHORS’ CONCLUSIONS: Herpes zoster vaccine is effective in pre-
venting herpes zoster disease. Although vaccine benefits are larger in
the younger age group (60 to 69 years), this is also the age group with
more adverse events. In general, zoster vaccine is well tolerated; it pro-
duces few systemic adverse events and injection site adverse effects of
mild to moderate intensity.
This is the abstract of a Cochrane Review published in the Cochrane
Database of Systematic Reviews (CDSR) 2012, issue 10. Art. No.:
CD008858. DOI: 10.1002/14651858.CD008858.pub2 (http://onlinelibrary.
wiley.com/doi/10.1002/14651858.CD008858.pub2/full). For full citation
and authors’ details, see reference 1.
The full text is available from: http://onlinelibrary.wiley.com/
The abstract is also available in the Portuguese, French, Span-
ish and Russian languages from: http://onlinelibrary.wiley.com/
1. Gagliardi AM, Gomes Silva BN, Torloni MR, Soares BG. Vaccines for
preventing herpes zoster in older adults. Cochrane Database of Syst
Immunosenescence is characterized, among other changes, by a
functional decrease in lymphocytes, particularly T lymphocytes, with
decreased immune protection and reduced vaccine response. This ex-
plains the higher incidence and severity of complications of herpes in
this older patients. Despite the low mortality of the disease itself, the
presence of pain, which is often intense and long lasting, is also more
severe in the elderly population. Herpetic neuropathy may be respon-
sible for limitations on activities and decreased quality of life. Since the
treatment, which is primarily through antiviral agents and analgesia,
presents variable results, immunization may provide notable support
for the elderly. Since the vaccine response among the elderly is also
variable and often low, studies on vaccine responses in this popula-
tion are especially welcome in order to structure primary prevention
of this disease.
The authors conducted a systematic review studying vaccination for
prevention of herpes zoster in the elderly and located three articles
with a low probability of bias. Their analysis on these papers provides
the information that vaccination, compared with placebo, is effective in
halving the risk of disease, with a benefit in terms of number needed to
treat (NNT) of 50. Moreover, vaccination presents relatively low adverse
reactions, with a risk in terms of NNT of 100. The younger age group
(60-70 years) had a greater vaccine response, as well as higher risk of
adverse effects, which is consistent with better immunity than in the
older group. This study shows, from the point of view of geriatrics, that
there is a tangible benefit from vaccinating the elderly against herpes.
Luiz Eugênio Garcez Leme, MD, PhD. Associate Professor, Faculdade de
Medicina da Universidade de São Paulo (FMUSP), and chief Geriatrician,
Godoy Moreira Institute, Hospital das Clínicas, Faculdade de Medicina
da Universidade de São Paulo (HCFMUSP), São Paulo, Brazil.