Vaccine Shortages: Implications for Pediatric Nurse Practitioners
Vaccine Shortages: Implications for Pediatric Nurse Practitioners
Vaccine shortages have occurred since the 1960s, but most shortages were brief, with minimal disruption to day-to-day practice and little interference with national immunization goals. Over the past 5 years, vaccine shortages have been more frequent and of longer duration and have interfered with adherence to the recommended childhood vaccination schedule. Pediatric Nurse Practitioners (PNPs) must alter vaccine schedules when shortages occur, devise catch-up immunization when shortages are alleviated, and explain to parents why the vaccine schedule must be changed (Klein & Myers, 2006). A close look at four recent childhood vaccine shortages offers PNPs important background information for changing role demands in the area of childhood immunization.
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school attendance provisions requiring students to have had a Td booster at age 11 years or older were temporarily rescinded and then reinstituted in 2002 when the shortage resolved (CDC, 2002).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.
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).
In October 2004, the nations 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.
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.
Vaccine shortages
Vaccine shortages have occurred since the 1960s, but most shortages were brief, with minimal disruption to day-to-day practice and little interference with national immunization goals. Over the past 5 years, vaccine shortages have been more frequent and of longer duration and have interfered with adherence to the recommended childhood vaccination schedule. Pediatric Nurse Practitioners (PNPs) must alter vaccine schedules when shortages occur, devise catch-up immunization when shortages are alleviated, and explain to parents why the vaccine schedule must be changed (Klein & Myers, 2006). A close look at four recent childhood vaccine shortages offers PNPs important background information for changing role demands in the area of childhood immunization.
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 nations 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.
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