Doctors often urge older patients to get the shingles
vaccine because it can prevent or cut the severity of this viral disease. But
according to a new study, the vaccine may be less effective in people with
Based on their findings, researchers from the University of
California, Los Angeles, suggested the diagnosis and treatment of depression in
older people could increase the effectiveness of the shingles vaccine and
reduce the risks associated with this painful skin condition. Shingles - marked
by an inflamed rash - is caused by the reactivation of the virus that causes
The study involved 40 people age 60 or older who were
diagnosed with a major depressive disorder. Over the course of two years, the
researchers examined the immune response of these patients to the shingles
vaccine and compared them to 52 people who were the same age and gender but did
not suffer from depression. The participants' immune responses were measured
when the study began, then again six weeks later, one year and two years after
receiving the vaccine, or an inactive placebo.
The findings revealed that people who had untreated
depression had lower immunity to the virus and were less able to respond to the
shingles vaccine than those who were not depressed or were taking medications
to treat their depression.
The researchers concluded that untreated depression reduced
the effectiveness of the shingles vaccine. Antidepressants, however, seemed to
"normalize the immune response to the zoster [shingles] vaccine,"
study leader Dr Michael Irwin said in a journal news release.
The study authors pointed out that antidepressants increased
the effectiveness of the vaccine even when they did not ease a person's
symptoms of depression.
While the study found an association between untreated
depression and reduced effectiveness of the shingles vaccine, it did not prove
a cause-and-effect relationship.
"Efforts are also needed to identify and diagnose
depressed elderly patients who might benefit from either a more potent vaccine
or a multi-dose vaccination schedule," Irwin noted in the news release.
In addition, more studies are needed to investigate the link
between untreated depression and the risk for shingles, the researchers
suggested. The link could have far-reaching implications if antidepressants
increase the effectiveness of other vaccines, such as the flu shot, for people
with depression, they pointed out.
Older adults are at greater risk for shingles, and more than
a million new cases occur in the United States every year, according to
background information in the news release.
The US Centers for Disease Control and Prevention provides
more information on the shingles vaccine.