The future of polio immunization in the United States: are we ready for change?

Parental attitudes toward multiple poliovirus injections following a provider recommendation

OBJECTIVES

Changes to the polio vaccination schedule, first to a sequential inactivated poliovirus/oral poliovirus (IPV/OPV) schedule in 1996 and most recently to an all-IPV schedule, require infants to receive additional injections. Some surveys show parental hesitation concerning extra injections, whereas others show that parents prefer multiple simultaneous injections over extra immunization visits. This study describes parental behavior and attitudes about the poliovirus vaccine recommendations and additional injections at the 2- and 4-month immunization visits.

METHODS

Beginning July 1, 1996, providers in eight public health clinics in Cobb and Douglas Counties, Georgia, informed parents of polio vaccination options and recommended the IPV/OPV sequential schedule. A cross-sectional clinic exit survey was conducted from July 15, 1996, to January 31, 1997, with parents whose infants (younger than 6 months) were eligible for a first poliovirus vaccination.

RESULTS

Of approximately 405 eligible infants, parents of 293 infants were approached for an interview, and 227 agreed to participate. Of those 227 participants, 210 (92%) parents chose IPV for their infant and 17 (8%) chose OPV. Of greatest concern to most parents was vaccine-associated paralytic polio (VAPP) (155, or 68.3%); the next greatest concern was an extra injection (22, or 9.7%). These parental concerns were unrelated to the number of injections the infant actually received.

CONCLUSIONS

After receiving information on polio vaccination options and a provider recommendation, parents overwhelmingly chose IPV over OPV. Concern about VAPP was more common than objection to an extra injection. The additional injection that results from using IPV for an infant's first poliovirus vaccination appears to be acceptable to most parents.

Impact of multiple injections on immunization rates among vulnerable children

BACKGROUND

In 1997, the Advisory Committee on Immunization Practices (ACIP) recommended a switch from oral polio vaccine (OPV) to inactivated polio vaccine (IPV) for the first two infant doses. The ACIP also recommended use of diphtheria, tetanus, and acellular pertussis vaccine (DTaP) for infants. These recommendations resulted in two additional injections at the 2- and 4-month immunization visits. This study evaluates the implementation of new IPV and DTaP immunization recommendations and their impact on immunization coverage levels.

METHODS

Immunization coverage was assessed in public clinics in three urban areas before and after the recommendations. One pre- and three post-recommendation cohorts were followed to 12 months of age.

RESULTS

Almost all (> or = 88%) infants in the pre-recommendation cohort received OPV, DTP, and only one or two injections. Almost all (> or = 78%) infants in the post-recommendation cohorts received IPV, DTaP, and three or four injections. The percentage of infants in the post-recommendation cohorts up-to-date for immunizations at 12 months of age was slightly higher than those in the pre-recommendation cohort.

CONCLUSIONS

Providers rapidly switched from OPV and DTP to IPV and DTaP. Coverage at 12 months of age was higher among IPV/DTaP recipients than among OPV/DTP recipients. Provider and parent acceptance of four injections at a visit was high. The recent pneumococcal conjugate vaccine recommendations potentially add a fifth injection at 2 and 4 months of age. Acceptance or rejection of five injections by providers and parents needs early assessment.

Vaccination visits in early childhood: just one more visit to be fully vaccinated

BACKGROUND

This study characterizes the healthcare visits at which children receive vaccinations, including the number of these visits and the number of vaccinations that are administered.

METHODS

The 1999 National Immunization Survey (NIS) is a nationally representative sample of children aged 19 to 35 months, verified by provider records, that is conducted to obtain estimates of vaccination coverage rates. We describe the number of healthcare visits in which one or more vaccinations were given, the number of vaccinations given at these visits, and the number of visits and vaccinations needed for an underimmunized child to complete the recommended vaccination series.

RESULTS

Of the children who did not receive all doses of the recommended vaccinations (4:3:1:3:3 vaccination series), three fourths had four or more immunization visits. Vaccination coverage increased as the number of visits increased, and children who had completed the series were more likely to receive multiple vaccinations than those who had not. Most children (70.7%) received a maximum of four vaccinations in any immunization visit. The majority of children (73.5%) who had not completed the 4:3:1:3:3 vaccination series needed only a single visit to complete the series. The majority (61.7%) of children who needed only one visit also needed only one additional vaccination.

CONCLUSIONS

While estimated national coverage for all recommended vaccinations is considerably below the Healthy People 2000 and Healthy People 2010 goal of 90%, achieving this goal is in essence just one visit away. If all children who needed one more visit were to receive that final visit, the national coverage among children 19 to 35 months for all recommended vaccinations would be 93%.

Poliovirus vaccines. Progress toward global poliomyelitis eradication and changing routine immunization recommendations in the United States

Poliomyelitis prevention in the United States has relied virtually exclusively on OPV during the past 30 years. Starting in 1997, a major change in the poliomyelitis vaccination policy occurred, facilitated by substantial progress toward worldwide poliomyelitis eradication. A sequential schedule of IPV followed by OPV became the preferred means to prevent poliomyelitis, although an all-OPV and an all-IPV schedule were considered acceptable alternatives. In 1999, two doses of IPV were recommended to start the primary series, followed by two doses of either poliovirus vaccine. As of January 2000, an all-IPV schedule is currently being implemented in the United States for routine childhood vaccination. Several unusual features are associated with the major public health policy change from an all-OPV to a sequential schedule, including (1) the process of involving a neutral party (i.e., the IOM); (2) the perceived concerns expressed before the change in policy with regard to provider and parent compliance, which could affect the hard-earned gains in raising immunization coverage rates; (3) the ethical issues surrounding the change (e.g., societal versus individual protection) and the influence that a single case of VAPP may have on national policy; (4) the relative lack of importance of cost-effectiveness data; and (5) the weight of progress in the global polio eradication initiative spurring the change in the United States and, increasingly, in other industrialized countries. The IOM assisted in the evaluation of the national poliomyelitis vaccination policy in 1977 and again in 1988. The 1988 review recommended that a sequential IPV-OPV schedule be considered at such time that a combination vaccine becomes available. Also, the IOM raised several important questions. Extensive research to address the questions raised by the IOM had been conducted so that, in 1996, more data were available for the decision-making process. The primary reasons for the change in vaccination policy were (1) the continued occurrence of VAPP in the absence of indigenously acquired wildtype poliovirus-associated paralytic disease, (2) the reduced risk for importation and spread of wild-type poliovirus caused by the progress of the global polio eradication initiative, (3) evidence from vaccine trials that combined IPV-OPV schedules are safe and immunogenic, and (4) maintenance of high levels of population immunity to poliovirus. The global effect of a national change in poliomyelitis vaccination policy was also considered in this policy-making process. Some members of the public health and medical communities raised objections that an increased reliance on IPV in the United States could lead other countries, especially developing countries, to inappropriately abandon OPV and increase reliance on IPV for routine vaccination. Experience from the global smallpox eradication campaign indicated that this scenario was unlikely. The United States ceased vaccinating against smallpox in 1971, 6 years before smallpox was eliminated from the world, without jeopardizing the global smallpox campaign. Subsequently, the effect on the global eradication initiative has been negligible. This article illustrates the potential discrepancy between expressed theoretic concerns about the number of injections and the actual practice once vaccination policy recommendations become the standard of care and that appropriate training and education can overcome these initial concerns. The authors found that compliance with the recommended use of IPV for the first and second doses as part of the sequential schedule was high, independent of socioeconomic status and ethnicity. The need for additional injections did not present a barrier to completion of the recommended childhood immunization schedule. (ABSTRACT TRUNCATED)

Impact of the sequential poliovirus immunization schedule: a demonstration project

OBJECTIVE

Researchers for this project evaluated compliance with the sequential poliovirus immunization schedule that uses inactivated poliovirus vaccine (IPV) for the first 2 doses of the polio immunization series, and assessed immunization coverage rates before and after implementation of this schedule at 6 public health clinics serving 1 county in Georgia.

DESIGN

Immunization histories for 3 birth cohorts of infants were compared: (1) the baseline cohort, born January 1 through June 30, 1995; (2) the evaluation cohort, born January 1 through June 30, 1997, after implementation of the schedule change; and (3) the dose-3 cohort, born August 1 through November 30, 1996 (i.e., old enough to be eligible for a third dose of poliovirus vaccine following implementation of the sequential schedule).

RESULTS

Following implementation of the new poliovirus immunization recommendations, 94% (534 of 567) of infants who received their first dose of poliovirus vaccine by age 3 months received IPV. Among these infants, 99.6% (532 of 534) were also up to date (UTD) for first doses of diphtheria and tetanus toxoids and acellular pertussis vaccine (DTP1/DTaP1), 99.6% (532 of 534) were UTD for first doses of hemophilus influenza type b (Hib 1), and 98.6% (527 of 534) had received at least one dose of Hepatitis B. Among infants visiting the clinics for their first or second dose of poliovirus vaccine, DTaP/DTP, and/or Hib, 76% received 3 or 4 simultaneous injections. In the dose-3 cohort, 78% (145 of 185) of infants who received a third dose of poliovirus vaccine had received 2 doses of IPV and 1 dose of oral poliovirus vaccine.

CONCLUSIONS

Compliance with the recommended use of IPV for the first 2 poliovirus immunization doses as part of the sequential schedule was very high in this low-income and ethnically diverse population. Furthermore, the need for additional injections did not impede the delivery of recommended childhood immunizations.

Videotape increases parent knowledge about poliovirus vaccines and choices of polio vaccination schedules

OBJECTIVE

To study the effect of an educational videotape about poliovirus vaccines and choices of schedules for parents/guardians of children starting the polio vaccination series.

DESIGN

Prospective, randomized trial comparing two educational interventions.

SETTING

Five pediatric offices (two university-based, two health maintenance organization staff models, and one private practice) and a local health department immunization clinic in the greater Lansing, MI, area.

PARTICIPANTS

A total of 287 parents/guardians of 2- to 3-month-olds presenting for well-child care and due for the first set of immunizations including poliovirus vaccine.

INTERVENTIONS

Parents/guardians were randomized to read the vaccine information statement (VIS) alone or to read the VIS and view a 15-minute videotape about polio vaccination and choices of schedules produced by Michigan State University. The intervention groups were similar by race/ethnicity, education, and relationship to the child.

OUTCOME MEASURES

Change in knowledge about the risk of poliomyelitis in the United States, transmission of poliomyelitis, characteristics of the two poliovirus vaccines, and choices of polio vaccination schedules; and parent opinion on effectiveness of the interventions, as measured by pre- and postintervention questionnaires.

RESULTS

Both interventions resulted in increased test scores of knowledge. However, videotape viewers scored significantly higher on their posttest compared with parents/guardians assigned to VIS only. This significant increase was noted across all practice types, two of three major racial/ethnic groups, and educational levels. (The increase for Hispanic parents/guardians approached significance). Reading the VIS did not improve posttest scores for videotape viewers. Reading the VIS did improve posttest scores for those assigned to VIS only, but these scores still were not as high as for videotape viewers who did not read the VIS.

CONCLUSIONS

This study demonstrated that a complicated discussion of risks/benefits of two vaccines and their schedules of administration could be communicated effectively via a videotaped presentation. In addition, the videotape was more effective than VIS alone in increasing short-term knowledge, regardless of practice type, race/ethnicity, or educational level. As immunization schedules increase in complexity and parents are asked to make more choices, videotaped information may be a better method to achieve the goal of truly informed consent.

Childhood immunisation today

Better knowledge of the pathogenesis of infections and host responses, and progress in biotechnology, have paved the way for new vaccines. In spite of rapid progress with several vaccine candidates, overoptimism is, however, not warranted. There is usually several years' delay before the new vaccine from the laboratory is available in practice. Acellular pertussis vaccine and rotavirus vaccine are examples of new vaccines that are currently being introduced; varicella, inactivated polio, and hepatitis B vaccines have been suggested for use in a new and more efficient way. In order to keep up high motivation among families and thus high vaccination coverage, more emphasis must be put on information about vaccines, their properties and proper use. Economic analyses are becoming more important in the decision to use new vaccines. Therefore, cost-benefit, cost-effectiveness and cost-utility analyses need to be conducted so that a basis can exist for determining a rational policy.