by H. Cody Meissner, M.D., FAAP
Shoulder injury related to vaccine
administration (SIRVA) is believed
to be caused by an immune response
following inadvertent, direct injection
of a vaccine into the deltoid bursa or
The presentation of SIRVA typically includes rapid onset of severe,
long-lasting shoulder pain following
vaccination in the deltoid muscle, resultant limited range of motion and
absence of infection. Data from the
Vaccine Adverse Event Reporting System suggest SIRVA is being reported
with increasing frequency.
Which of the following statements
regarding vaccine administration are
a) The suggested route of administration for each
vaccine is recommended by the manufacturer
and is based on studies showing maximum safe-
ty and immunogenicity.
b) The presence or absence of an adjuvant is not
a factor when considering vaccine administra-
c) For most infants younger than 12 months of
age, the anterolateral thigh muscle is the pre-
ferred site because it has more muscle mass than
the deltoid muscle.
d) The buttock generally should not be used for
active immunization because of limited absorp-
tion from gluteal fat.
Vaccines should be administered in an anatomic
area where neural, vascular or tissue injury is unlikely
to occur. For intramuscular injections, the needle
length should be long enough to ensure injection
occurs in the muscle mass. Too long a needle length
increases the risk that injection may involve nerves,
blood vessels or skeletal structures. Suggested needle
lengths are presented in the 2015 Red Book (Table
1.7, page 28, http://bit.ly/2tgo990). Most intramuscular injections are performed with a 22- to
Injectable vaccines are administered by the intramuscular, subcutaneous or intradermal routes except
for the smallpox vaccine, which is administered by
the percutaneous route using a bifurcated needle
Selection of the proper injection site and needle
length depends on the amount of muscle and adi-
pose tissue at the selected site, the child’s age and the
volume to be injected. Inactivated vaccines contain-
ing an adjuvant should be injected into muscle to
avoid the risk of local irritation, skin discoloration
and granuloma formation that may be associated
with subcutaneous injection.
For infants less than 1 month of age, a ⅝-inch
needle is suggested for injection in the anterolateral
thigh. For term infants 1 through 12 months of
age, a 1-inch needle is suggested. For toddlers and
children, either the anterolateral thigh or deltoid
muscles are suggested. If two vaccines are administered in the same limb at the same visit, they should
be spaced 1-inch apart.
Transient, mild shoulder discomfort following
immunization in the deltoid muscle is a common
side effect of vaccination. Severe, persistent shoulder pain in association with prolonged limitation of
function is rare.
SIRVA identifies a specific condition that is associated with vaccine inadvertently administered into
the deltoid bursa or joint space. Patients with SIRVA
experience shoulder injury that is more severe than
would be expected from just needle trauma. One
theory suggests that an immune reaction to one or
more components of the vaccine may be responsible
for signs and symptoms of SIRVA.
In a series of 13 cases among adult patients published by the Vaccine Injury Compensation Program
(Atanasoff S, et al. Vaccine. 2010;28:8049-8052),
shoulder pain was noted immediately after vaccination in 50% of cases, and pain developed in 90%
within 24 hours. The most common findings on
physical examination were painful and limited range
of motion. Arm weakness and sensory changes were
uncommon. Deep tendon reflexes were normal.
Symptoms persisted six months to several years, and
30% of patients required surgery.
Several theories have been proposed to explain
why SIRVA is reported less fre-
quently in children, despite the
number of vaccines adminis-
tered. Administration in the an-
terolateral thigh avoids the risk
of joint involvement; bunching
of the subcutaneous and deltoid
tissue prior to vaccination may
increase the distance to the
shoulder; and the developing
subacromial bursa may be less
developed (smaller) in children.
Most cases in adults occur
after administration of a vac-
cine to which some immunity
already exists because of previ-
ous immunization such as in-
fluenza or tetanus-containing
vaccines. This may result in a
greater inflammatory response
following inadvertent injection
into the skeletal structures of the shoulder.
The number of people for whom compensation
for SIRVA was awarded by the Vaccine Injury Compensation Program in 2016 was 202 cases. Many
instances of SIRVA may be avoided by proper vaccination technique and positioning.
Dr. Meissner is professor of pediatrics
at Floating Hospital for Children, Tufts
Medical Center. He also is an ex officio
member of the AAP Committee on Infectious Diseases and associate editor of
the AAP Visual Red Book.
Shoulder injury related to vaccine administration
reported more frequently
A n s w er: a, c a n d d are c orre ct