Notice to Readers: Updated Recommendations on the Use of
Pneumococcal Conjugate Vaccine in a Setting of Vaccine Shortage --- Advisory
Committee on Immunization Practices
In September 2000, CDC published an interim vaccination schedule
recommended by the Advisory Committee on Immunization Practices (ACIP) to be used during
a pneumococcal conjugate vaccine shortage that was anticipated to be brief
(1,2). Because the duration of the shortage has been longer and the severity has
been greater than anticipated, ACIP has revised these recommendations to
health-care providers who had been advised to conserve vaccine by decreasing the number
of doses administered to healthy infants rather than to leave some infants
unvaccinated. For infants who receive their first dose before age 6 months, vaccination with
a maximum of 3 doses is recommended; the fourth dose should be deferred. All
health-care providers should reduce the number of vaccine doses used and
ordered, regardless of their current supply, so that vaccine is more widely available
until supplies are adequate.
Because of greater-than-expected demand, vaccine has been back ordered for
the public sector throughout most of 2001. In August, the situation worsened when
facility and product testing-related limitations at the manufacturer's production sites
halted distribution for several weeks. Under a full vaccination schedule, approximately
1.5 million doses are needed per month; the manufacturer estimates that 90% of
the doses are used for the 4-dose infant vaccination series, and 10% are used for
catch-up vaccination. During September, approximately 700,000 doses were distributed
(47% of the 4-dose infant schedule), and in October, approximately 600,000 doses
were distributed (40%). The manufacturer anticipates the distribution of approximately
1.2 million doses per month during November 2001--March 2002 (86%)
and approximately 2.0 million doses per month during April 2002--mid-2002 (142%).
Until adequate supplies are available, ACIP recommends the following:
Vaccine should be administered to high-risk children aged <5 years
as recommended by ACIP in October 2000 (1), including children with sickle
cell disease and other hemoglobinopathies; anatomic asplenia; chronic
diseases (e.g., chronic cardiac and pulmonary disease, and diabetes);
cerebrospinal fluid leak; human immunodeficiency virus infection and
other immunocompromising conditions; immunosuppressive chemotherapy
or long-term systemic cortico-steroid use, and children who have
undergone solid organ transplantation.
Healthy infants and children aged <24 months should receive a
decreased number of pneumococcal conjugate vaccine doses on the basis of the age
at which vaccination is initiated and the estimated amount of vaccine
available to the health-care provider's practice (Table 1). On the basis of birth,
cohort size and recent experience with vaccine supply, if health-care
providers estimate a shortfall of <25% of the 4-dose infant schedule, a
moderate shortage schedule is recommended. If estimates suggest a greater
shortfall, the severe shortage schedule is recommended. If shortages are estimated
to be more severe (>50%), health-care providers should set infant
vaccination priorities based on the assessment of risk, deferring infants at lowest
risk. Demographic risk factors for invasive infections include being black
or American Indian (1); exposure risk factors include not breastfeeding
and attendance at out-of-home child care (3).
Limited data support a 2-dose schedule among infants; however,
this regimen is preferable to vaccinating some children with 3 doses and
not vaccinating others. Efficacy data from a randomized controlled
trial prelicensure suggest that 1 or 2 doses of pneumococcal conjugate
vaccine are protective during the 2-month interval before the next dose with a
point estimate of 86% efficacy but a 95% confidence interval that includes zero
(4). Immunogenicity data indicate increases in antibody titer following 2 doses
for all vaccine serotypes except 6B (5). For all serotypes, 2 doses of
conjugate vaccine probably increase antibody avidity and induce immunologic
memory that is boosted by subsequent antigenic exposure. Acceptable
2-dose regimens include vaccination at ages 2 and 4 months, 2 and 6 months, or
4 and 6 months. The major advantage of regimens that begin at age 2
months is earlier provision of protection. Immunogenicity may be improved
by increasing the interval between doses and vaccinating at ages 2 and
6 months or by vaccinating at ages 4 and 6 months. "Carrier priming"
has been documented with the CRM197Haemophilus
influenzae type b conjugate vaccine (6), but the impact has not been evaluated for
pneumococcal conjugate vaccine. Although immunogenicity would be greater
if pneumococcal conjugate vaccination were deferred until after age 6
months (e.g., ages 7 and 9 months), this regimen would leave younger
infants unprotected and would require additional vaccination visits.
Health-care providers should maintain a list of children for whom
conjugate vaccine has been deferred so that it can be administered when the
supply allows. The highest priority for vaccination among children who have
been deferred is infants vaccinated with 2 doses. Infants who have received
3 doses and are eligible for a fourth dose would be a second priority group.
Pneumococcal polysaccharide vaccine is not licensed or recommended
for children aged <2 years. Although a study indicated that administration of
this vaccine at age 15--18 months may substantially boost antibody levels
among children primed with 3 doses of conjugate vaccine (University of
Chicago, unpublished data, 1995), this study did not use the licensed
conjugate preparation. ACIP recommends additional study to evaluate the
immune response to a polysaccharide vaccine booster dose among children aged
Because data are limited on the long-term efficacy of a 3-dose or 2-dose
vaccine regimen for young infants, health-care providers are encouraged to report
invasive pneumococcal disease following pneumococcal conjugate vaccine to CDC
through state health departments. If pneumococcal isolates are available from
vaccinated children, CDC can perform serotyping to determine whether it is a type included in
the vaccine. Additional information about this study is available at http://www.cdc.gov/nip/home-hcp.htm; other information is available at CDC's Respiratory Diseases
Branch, telephone 404-639-2215; fax 404-639-3970.
Levine OS, Farley M, Harrison LH, Lefkowitz L, McGeer A, Schwartz B. Risk factors
for invasive pneumococcal disease in children: a population-based case-control study
in North America. Pediatr 1999;103:E28.
Black S, Shinefeld H, Fireman B, et al. Efficacy, safety, and immunogenicity of
heptavalent pneumococcal conjugate vaccine in children. Pediatr Infect Dis J 2000;19:187--95.
Rennels MB, Edwards KM, Keyserling HL, et al. Safety and immunogenicity of
heptavalent pneumococcal vaccine conjugated to
CRM197 in United States infants. Pediatrics
Granoff DM, Rathore MH, Holmes SJ, et al. Effect of immunity to the carrier protein
on antibody responses to Haemophilus
influenzae type b conjugate vaccines. Vaccine 1993;11(Suppl 1):S46--S51.
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