Ask the Mayo Clinic:
Whatever happened to 'jet injectors?'
Published 10:00 pm, Sunday, December 7,
Dear Mayo Clinic: I remember we used to
get vaccines and other shots using an
air gun, and lots of people could get
shots quickly. I haven't seen this done
for a long time. Why? Were problems
discovered with that method? It seems
that it would be an efficient way to
give flu shots, for instance, in a
really short time.
A: Using an air gun -- also called a jet
injector -- is a fast way to deliver
vaccines. But jet injectors were
discontinued for mass vaccinations about
five years ago because of possible
A jet injector uses high pressure to
force a vaccine or other medication
through a person's skin. Their speed
made jet injectors very efficient, so
many people could be vaccinated quickly.
They were often used in the military.
Although they weren't pain-free, jet
injectors didn't involve needles. The
result was less discomfort than a needle
injection, and they caused less anxiety
in people who were afraid of needles.
In some cases, however, jet injectors
could bring blood or other body fluids
to the surface of the skin while the
vaccine was being administered. Those
fluids could contaminate the injector,
creating the possibility that viruses
could be transmitted to another person
being vaccinated with the same device.
Of particular concern were viruses
transmitted by blood, such as human
immunodeficiency virus (HIV), hepatitis
B and hepatitis C. HIV can lead to
acquired immunodeficiency syndrome
(AIDS) -- a chronic, life-threatening
condition caused by damage to the immune
system. Hepatitis can cause chronic
inflammation of the liver and lead to
serious liver damage.
Greater awareness of these diseases and
other blood-borne illnesses led to
increased scrutiny of ways they might be
spread. Although no widespread outbreaks
of these diseases were caused by jet
injectors, the risk of blood and body
fluid contamination of the equipment
made jet injectors no longer acceptable
for vaccinations. Instead, most vaccines
now are administered by needle
injection, typically in the arm for
adults and in the thigh for children.
In the case of the flu vaccine, another
option that became available about three
years ago is a nasal mist. All it takes
is one spray in each nostril. It's easy,
quick and painless. No needles are
This method has limitations, though. The
nasal spray vaccine contains a low dose
of weakened live virus. If a person's
immune system is severely suppressed due
to illness or medical treatment, the
live virus could, theoretically, cause
the flu in that person. Also, the flu
vaccine nasal spray appears to be less
effective than needle injection (flu
shot) in people 50 and older. For these
reasons, the nasal spray is only
approved for healthy people ages 2 to
The flu shot is approved for people 6
months and older. Because the viruses in
the flu shot aren't live, it can't cause
you to get the flu but it will enable
your body to develop the antibodies
necessary to ward off influenza viruses.
Mayo Clinic recommends that everyone get
the flu vaccine. Although people tend to
think of influenza as a minor illness,
it can cause pneumonia and lead to
hospitalization, particularly in
high-risk groups. At particularly high
risk for influenza are all children 6
months to 18 years and everyone older
than 50. Others at increased risk of
flu-related complications are pregnant
women, people who have a chronic medical
condition such as heart disease,
diabetes or asthma, and anybody whose
immune system is compromised.
Unfortunately, about 36,000 Americans
die each year as a result of influenza.
So, it's important to get a flu vaccine
every year to protect yourself.
The current methods of delivering the
vaccine are safe and effective and,
although they aren't as fast as the jet
injectors, getting a flu vaccine doesn't
take much time.
Flu season lasts from fall through early
spring. The earliest Mayo Clinic usually
sees a flu outbreak is September or
October. But about 60 percent of
influenza outbreaks in the U.S. occur
Contrary to popular belief, even if you
don't get your flu vaccine by the end of
November, it's not too late. The
majority of outbreaks occur after that
time, and you can still receive the
vaccine as late as March or April.
-- Gregory Poland, M.D.,
Vaccine Research Group, Mayo
Clinic, Rochester, Minn.
2008 CDC- Jetguns (PCNIF) Fail Safety