Q:
What is Respiratory Syncytial Virus (RSV) and how does it affect humans?
Respiratory
syncytial virus is the most common respiratory pathogen in infants and young
children. It infects virtually all infants by the age of two years. In most
infants, the virus causes symptoms resembling those of the common cold. In
infants born prematurely and/or with bronchopulmonary dysplasia or heart
disease, RSV can cause a severe or even life- threatening disease. Each year RSV
disease results in over 90,000 hospitalizations and about 2% of these patients
die.
Q:
How easily is RSV transmitted?
RSV
is highly contagious. Each year, up to 50% of susceptible infants are infected.
RSV can spread very rapidly in the hospital environment; up to 40% of
hospitalized children may become infected. Transmission occurs by contact with
infectious secretions via hand contamination and self-inoculation of eyes, nose,
or mouth; or by contact with large-droplet aerosols or formites. RSV can survive
for 4-7 hours on countertops. Transmission may be prevented by standard
infection control practices, such as hand washing.
Q:
How often do outbreaks occur?
RSV
outbreaks occur on a yearly basis. In S. Florida, RSV is present year round, but
the incidence is higher from July to April.
RSV
infection does not protect against subsequent infections. When school age
children and adults get RSV, they may have symptoms of a common cold. If they
bring this virus to the home of a newborn, the newborn may get very ill.
Q:
How is RSV infection treated?
Treatment
of severe RSV infection is mostly supportive, to ensure adequate oxygenation,
hydration, and nutrition. ICU admission may be needed antiviral agent, Ribavirin,
a registered trademark of ICN, may be useful, in few cases.
Q:
Is there an RSV vaccine available?
At
this date, there are no safe and effective RSV vaccines. There are two effective
preventive agents available. Respigam (respiratory
syncytial virus immune globulin intravenous), a polyclonal antibody, provides
effective prevention against RSV, and Synagis (palivizumab), a monoclonal antibody, which provides
protection against serious lower respiratory tract infections caused by RSV in
infants and children at high risk for RSV disease. Synagis is more potent than Respigam,
and is administered by simple, monthly IM injections.
Q:
What is Synagis (Palivizumab)?
Synagis
is
a monoclonal antibody produced by recombinant biotechnology, which is
specifically designed to neutralize respiratory synical virus (RSV). Monthly
intramuscular (IM) injections of Synagis
prior to and during the RSV season have been shown to significantly reduce
RSV hospitalizations in infants at high risk.
Q:
What side effects are associated with Synagis?
In
the IM pact- RSV trial, there were no statistically significant differences in
adverse events between the Synagis
group and the placebo group. Adverse events that occurred in more than 1% of
patients in the Synagis group for
which the the incidence was
>
1%
higher than in the placebo group included upper respiratory infection, otitis
media, rhinitis, rash, pain, hernia, SGOT increased, and pharyngitis. Synagis
was discontinued in only five of 1,002 patients; two because of vomiting and
diarrhea, one because of moderate injection- site reaction, and two for
pre-existing conditions.
Q:
Does Synagis have any drug interactions?
No
formal drug-drug interaction studies were conducted. In the IMpact- RSV trial, Synagis
was associated with any increase in adverse reactions among children who
received routine childhood vaccines, influenza vaccine, bronchodilators, or
steroids.
Q:
Who should receive Synagis?
Synagis
is indicated for the prevention of serious lower respiratory tract disease
caused by RSV. Candidates for prophyaxis with Synagis include premature infants (32 weeks gestation) without
bronchopulmory dysplasia (BPD). Other candidates include infants with BPD
requiring medical management in the prior six months. Other infants (35 weeks
gestation) at risk for RSV may be considered on a case-by-case basis, especially
if any of the following risk factors are present multiple birth, crowded
household (> 4 people, or siblings) child will be going to day care, if
smokers are present in the household, especially the mother. Some infants may
benefit from prophylaxis for two RSV seasons.
Q:
Can Synagis be given with routine
childhood vaccines or other immune globulins?
Synagis
is not expected to interfere with routine childhood vaccines or other immune
globulins. However, no formal drug-drug interaction studies have been conducted.
In S. Florida, since
the RSV season is long, your doctor will help decide how long your baby will
need to get Synagis.
Please
remember that all children get infected with RSV. Synagis
is used for a few months to prevent severe disease caused by this virus. As your
child grows, the lungs grow as well. Therefore, as the child grows, the severity
of disease caused by RSV should be less.