Vaccine Shortages: Implications for Pediatric Nurse Practitioners

Tetanus Diphtheria Vaccine 

In the fall of 2000, tetanus diphtheria vaccine (Td) became in short supply. The Centers for Disease Control and Prevention (CDC) eventually prioritized Td’s use for emergency rooms and clinics that treat wounds. Routine Td boosters for adolescents were deferred so the limited vaccine supply would be available to individuals with burns and wounds; those at greater risk for tetanus. Statewide school attendance provisions requiring students to have had a Td booster at age 11 years or older were temporarily rescinded and then reinstituted in 2002 when the shortage resolved (CDC, 2002).

Wyeth’s withdrawal from Td vaccine production, which was abrupt and without warning and led to the dramatic shortfall of Td vaccine that lasted almost 2 years. Wyeth was producing 25% of all Td vaccine used in the United States. The Food and Drug Administration (FDA) requirement for a thimerosol-free vaccine would have required a costly reformulation and substantial upgrades to existing vaccine production facilities, so Wyeth decided to exit the Td production business (Congeni, 2004). Manufacturers who are for-profit industries must make a profit in order to continue producing a vaccine. The goal is ongoing profitability from both old and new vaccines. New vaccines are more profitable than older vaccines. For example, for private sector sales, the older Td vaccine commands $17.50 per dose; whereas the newer tetanus diphtheria acellular pertussis (TdaP) vaccine commands $30.75 per dose (CDC, 2006a). Vaccines also tend to be less profitable than other prescription medications. Annual revenues for Lipitor, a cholesterol-lowering medication, are greater than revenues for the entire worldwide vaccine industry. Prevnar, the highest revenue-generating vaccine, has annual gross US sales of about $1 billion; whereas many popular medications gross $7 billion per drug (Offit, 2005). Market forces, coupled with costs associated with modernizing facilities and reformulating vaccines, discourage manufacturers from staying in the vaccine business.

Pneumococcal Conjugate Vaccine 

From August 2001 through September 2004, there was a shortage of pneumococcal conjugate vaccine (PCV7). In 2001, the CDC’s response focused on allocating limited supplies of PCV7 using an abbreviated schedule. Vaccinators were asked to temporarily suspend routine use of the fourth dose of PCV7, a booster dose normally given at 12 to 15 months of age. Vaccinators moved to a three-dose series of one dose at 2 months, 4 months, and 6 months of age. Vaccinators were to continue to give the fourth dose to children at increased risk for severe disease. These interim modifications were made to conserve more than 1 million doses of PCV7 and curtail widespread disruptions to PCV7 vaccination goals (CDC, 2003). But in February 2004, another PCV7 shortage resulted in two more abbreviated schedules; at first suspending the fourth dose and soon thereafter suspending the third and fourth doses of PCV7 (CDC, 2004a). Even promoting a balanced inventory across states and public and private immunization programs didn’t guarantee PCV7 availability at the point of service; thus, adherence to the interim guidelines was sporadic.

The PCV7 shortage was attributed to greater than expected initial demand for the vaccine, which has a lengthy, complex production process. The risks and unpredictability associated with manufacturing biologics are more challenging than those entailed with manufacturing inert drugs. Vaccines are produced from living cells or organisms. After the vaccine agent is grown, it must be purified and then each lot must be evaluated for consistency, purity, and potency. In manufacturing PCV7, 300 separate quality-control tests are performed during production and one lot of vaccine takes 1 year to produce (Congeni, 2004).

Trivalent Inactivated Influenza Virus Vaccine 

In October 2004, the nation’s available supply of trivalent inactivated influenza virus vaccine (TIV) was abruptly cut in half. Many infants and young children, receiving the vaccine for the first time, did not receive the recommended booster dose 1 month later. Also, some high-risk infants and children were immunized late in the season or not at all. The CDC issued interim flu vaccine recommendations that prioritized high-risk people, health care workers, and close contacts of children under age 6 months (CDC, 2004b). However, for periods of time throughout the 2004 shortage, vaccinators could not obtain TIV, even if only to vaccinate high-priority individuals.

The TIV shortage of the fall of 2004 was widely publicized in the news media and became a subject of Congressional inquiries. Blaming this sudden vaccine shortfall largely on bacterial contamination at the Chiron plant in England quieted the national clamor but another issue received little public attention. During the TIV shortage in the fall of 2004, flu vaccine from Canada and Europe could not be imported owing to regulatory constraints. Each country regulates the vaccines for use by their citizens whether they are manufactured within or outside their borders. Vaccine manufacturers face the challenge of meeting multiple national regulatory requirements and must decide in which countries to seek licensure. Presently, there are no emergency regulatory procedures to permit expedited or temporary licensure of vaccines that have undergone similar regulatory review in other countries. The FDA is working on this problem through its membership on The International Committee on Harmonization (Klein & Myers, 2006).

Flu vaccine shortages and controversies over the way flu vaccine is distributed across the United States persist. The CDC and other key stakeholders are working together to solve these problems and improve flu vaccine availability for children served by both the public and private sectors.

Meningococcal Conjugate Vaccine 

In 2006, meningococcal conjugate vaccine (MCV4) joined the list of childhood vaccine shortages. Despite an earlier recommendation to prioritize 11- to 12-year-olds for MCV4, in May 2006, the CDC urged vaccinators to cease vaccinating 11- to 12-year-olds and prioritize MCV4 to adolescents at high school entry (age 15 years), entering college freshmen who will be living in dormitories, and high-risk groups, such as military recruits or travelers to places where meningococcal disease is high. Demand for MCV4 was higher than expected for 18-year-olds and evenly distributed among 11- to 17-year-olds during its first year on the market. The anticipated 2006 summer rush among 18-year-olds prompted CDC officials to modify recommendations to alleviate manufacturer supply problems (CDC, 2006b). Sanofi Pasteur officials have said that until their other manufacturing facility comes online in 2008, there may be periodic supply constraints (Rusk, 2006). Projecting vaccine needs and availability and monitoring vaccine uptake is a difficult and imprecise science.

Modify the Immunization Schedule 

Keeping up with sudden or repeated modifications to the vaccine schedule and mastering the nuances of each vaccine shortage’s temporary recommendations adds to the complexity of childhood immunization. Modifications issued by the CDC may involve an abbreviated schedule, prioritization, deferral, and referral as follows:

During the course of a vaccine shortage, PNPs may be faced with multiple temporary modifications imposed by the CDC. However, when a vaccine supply is delayed or unavailable at the point of service, adherence to CDC-issued modifications may be sporadic.

Provide for Catch-up Immunizations 

Vaccine shortages cause children to miss vaccines that they need, and some children may never catch up when the shortage is over. The problem of unvaccinated (late start) or under-vaccinated (lapsed doses) children threatens to decrease national vaccination rates. Therefore, PNPs must emphasize the continuing threat and seriousness of the disease the vaccine aims to prevent so parents will want to return for the vaccination when the shortage is over. The CDC may issue specific guidelines and catch-up regimens for unvaccinated, under-vaccinated, and high-risk children after the vaccine shortage is resolved. PNPs should incorporate CDC-issued regimens into their catch-up efforts.

PNPs must also devise reminder and recall strategies to put into place when the vaccine becomes available. These strategies inform parents that their child is due (reminder) or overdue (recall) for specific vaccinations using the mail, telephone, or internet. Notices in patient charts, computer tracking systems, and immunization registries can assist PNPs in their catch-up efforts. One of the most promising tools for managing catch-up vaccination is the immunization registry, which can track children who missed vaccines because of a shortage and send them appointment reminders when vaccine becomes available (Kairys, Gubernick, Millican, & Adams, 2006).

Address Parental Concerns 

Parents may be easily confused or become suspicious when the recommended number of doses or age recommendations temporarily changes because of a limited vaccine supply. A survey taken during the 2004 influenza vaccine shortage found a high level of public concern about the shortage, uncertainty about the reasons for the shortage, and varying opinions and attitudes about vaccine allocation decisions (DesRoches, Blendon, & Benson, 2005). Making parents aware of a vaccine shortage or fielding parent questions, fears, or misinformation about a particular vaccine delay entails coming up with brief, accurate talking points about vaccine production, supply, or distribution problems as follows: (1) Vaccines are expensive to make; some manufacturers have left the vaccine business. (2) Vaccines are complex biological agents; some take up to a year to produce. (3) Projecting vaccine supply and demand is an imprecise science; the CDC and manufacturers are refining their methods. (4) Vaccine schedule changes aim to vaccinate children at increased risk for severe disease. (5) We will notify you once the vaccine is available for your child.

Keep Current on Vaccine Shortages 

The CDC maintains a website with accurate information about vaccine shortages, which is periodically updated. Identify the vaccines with a delay or shortage, along with expected duration and modifications of routine recommendations. Learn more about past vaccine shortages. Find answers to questions about changes in child care and school requirements owing to vaccine supply problems. Find out more about regulatory issues related to vaccine supply through a link to the FDA’s Web page. This Web site should be of interest to PNPs, parents, or anyone with questions about a vaccine shortage. Visit www.cdc.gov/nip/news/shortages/default.htm.