Vaccine shortages

September 2001

---Philip A. Brunell, MD

There may be a need to modify immunization schedules for influenza virus vaccine and DTaP. The reason for the latter is the curtailment of manufacture of tetanus toxoid. The delivery of influenza vaccine probably will be delayed but it is not anticipated that this will be as bad as last year.

There was an anticipated shortage of tetanus toxoid-containing products in 2000, which was expected to be resolved early in 2001. However, in January of this year Wyeth announced it had stopped production of tetanus toxoid-containing products, tetanus and diphtheria toxoids and acellular pertussis vaccine (ACEL-IMUNE). And Baxter Hyland ImmunoVaccines, which acquired North American Vaccine Inc., is no longer producing DTaP vaccine (Certiva). Thus, the only suppliers of DTaP are Aventis Pasteur and Glaxo SmithKline, producers of Tripedia and Infanrix, respectively. However, CDC now indicates that the shortages of DTaP should not affect immunization with this vaccine.

On March 7, the FDA approved a newly formulated version of Tripedia in one-dose vials without preservative and with only a trace amount of thimerosal. However, the conversion to single-dose vials has resulted in additional delays of shipment of Tripedia to the federal government. This is not expected to affect those buying their vaccine privately. However, physicians receiving vaccines from the Vaccines for Children or 317 programs were expected to experience some shortages. Although it is usually recommended that one continue to use the same aP vaccine to complete the series, both the Red Book and CDC state that it is acceptable to switch brands in situations where the sequence would be interrupted by waiting until the same brand of vaccine became available.

If it becomes impossible to obtain enough DTaP to vaccinate all children, the first 3 doses in the series should be given and the fourth dose of vaccine postponed; however, this should not necessary since DTaP supplies appear to be adequate. If children do miss the fourth dose, they should be recalled when vaccine supplies are again adequate. The preschool dose should be given to assure immunity to these diseases during school attendance. These recommendations are summarized in a recent Morbidity and Mortality Weekly Report (MMWR. 2001; 50(10):189-190). The recommendations for tetanus toxoid for routine use and for wound management during this period have been published in MMWR (2000;49:1029–30). Wound management does not change and these recommendations can be found in the Red Book.

Presently, Aventis the only major manufacturer of tetanus toxoid and Td vaccines in the United States. Although they have increased production, it is anticipated that some shortage will continue at least until the end of the year. The major impact on pediatric practice is the recommendation that routine boosters for adolescents be postponed and that records of these individuals be maintained so that they can be recalled when the supply increases.

The delivery of influenza vaccine may be delayed but one should continue to vaccinate in November and December as supplies become available, since peak influenza activity during the past 19 seasons has occurred in January (26%), February (37%) and March (16%). Since delays are expected this year, immunize all high-risk people early in the influenza season (September and October) and others in November and December.

Influenza vaccine is recommended for those with chronic pulmonary or cardiac disease, including asthmatics, people with immunosuppressive disorders, and those with renal and metabolic disorders, eg, diabetes, who require ongoing medical care. These recommendations can be found in the Red Book. Self screening forms to help individuals determine if they or their children need an influenza vaccination early because they are in a high risk group can be found at www.cdc.gov/nip/flu/.

Even children without risk factors should not be denied influenza vaccine if it is requested — just wait until later in the season. Children that might be immunized early are those living with vulnerable persons, eg, grandparents, or graduates of NICUs. One will need to use a fair amount of discretion in allocating influenza vaccine, as well as these other vaccines in the coming months. The good news is that there is nothing like a shortage to create a demand.