CDC panel recommends pertussis vaccine for HCWs

A cost-effective investment in HCWs, patient safety

In a unanimous vote, described as a "slam-dunk" by one committee member, the Advisory Committee on Immunization Practices (ACIP) recommended that hospitals and ambulatory care settings offer free pertussis vaccination to health care workers. The provisional recommendation now awaits finalization by the Centers for Disease Control and Prevention (CDC), which is expected to approve it and make it an official employee health guideline.

"This will be perceived as a new challenge, but the recommendations are strong, the scientific basis is accurate, and we look forward to helping institutions implement it. I know our institution is planning to do so," says William Schaffner, MD, chairman of the department of preventive medicine at the University of Vanderbilt Medical Center in Nashville, TN, and a liaison member of ACIP representing the National Foundation for Infectious Diseases.

The idea is to protect health care workers and their patients, particularly neonates who would not be indicated for pertussis vaccination but may be vulnerable to complications after infection. Large outbreaks of pertussis have occurred in health care facilities through the failure to recognize and isolate infected infants and children, to recognize and treat disease in staff members, and to institute infection control measures rapidly.1 Expensive and time-consuming follow-up in such cases may include work furloughs for some workers and post-exposure prophylaxis (PEP) with erythromycin or other antibiotics.

New vaccine changes everything

The pertussis picture changed dramatically last year with licensure of a tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap), which is designed as a single-dose booster vaccine for people 11-64 years of age. It provides protection against tetanus, diphtheria, and pertussis. Although most children are protected against pertussis by vaccination during childhood, immunity wanes over time and leaves adults unprotected. In 2004, U.S. adults 19-64 years of age accounted for 7,008 of 25,827 (27%) reported pertussis cases. The true number of cases among adults 19-64 years is likely much higher, estimated at 600,000 each year, ACIP says. The clinical presentation of pertussis in adults ranges from mild cough illness to classic pertussis (i.e., prolonged cough characterized by paroxysms, post-tussive emesis, and inspiratory whoop), ACIP reports. Complications include rib fractures resulting from severe cough and pneumonia requiring hospitalization.

The recommendation approved by ACIP at a Feb. 22 meeting at the CDC in Atlanta states in part that: "Health care workers who work in hospitals or ambulatory care settings and have direct patient contact should receive a single dose of Tdap as soon as feasible if they have not previously received Tdap." In essence, the vast majority of health care workers would be covered by a previously approved general recommendation to immunize adults younger than 65 years old, but ACIP is trying to jump-start the issue in hospitals.

"There is now a provisional recommendation, as of October 2005, that all adults [younger than 65] receive a dose of the Tdap vaccine to replace the next tetanus booster that they would be scheduled to have," says Trudy Murphy, MD, a medical epidemiologist with the CDC national immunization program. "What this recommendation says is that we want hospital health care workers to get this vaccine as soon as possible — if at least two years have passed since their last tetanus and diphtheria booster — in order to protect them from pertussis and any patients they might expose."

Infant care workers priority

ACIP advised that the first priority should be immunizing health care workers who care for infants younger than 12 months old. "They would be first, then all other health care workers that have direct contact with patients would be the second priority," Murphy explains. "After that, [immunize] the employees that don't have direct patient contact, who would fall under the general recommendation anyway, because we can't control [employee contact with patients]."

The committee approved the recommendation unanimously with relatively little discussion, which primarily centered on cost issues for hospitals and assurances that workers would not be charged for the vaccine.

"Whenever a recommendation is made that increases a hospital's cost, people will want good evidence that they will benefit from it," Murphy tells Hospital Employee Health. "In this case, we are quite certain that there will be benefits for the health care worker and for preventing transmission to others in the health care setting. At this time, because we do not have any studies to demonstrate it, we can't predict what the cost savings will be for hospitals implementing these programs, but our modeling [studies] suggest that there will be cost savings."

Indeed, the CDC projected cost benefits presented at the meeting indicating that every dollar invested in pertussis vaccine will reap $2.40 back for the institution in prevented infections, exposures, and infection control measures.

"A Tdap vaccination program in health care workers could have a substantial impact in reducing hospital-acquired pertussis morbidity by reducing the number of annual [pertussis] exposures by 46%," said Ismael Ortega-Sanchez, PhD, a researcher in the national immunization program at the CDC. "Benefits or savings from Tdap vaccination could be sizable for hospitals even after they cover program costs."

Additional studies are needed to determine whether immunized workers could forego post-exposure prophylaxis after exposure to pertussis-infected patients. "If we can learn in the near future that PEP is not needed if a health care worker is vaccinated, additional cost savings could be possible," Murphy says.

For employee health professionals, the question about PEP leaves some lingering uncertainty about the vaccine. "The vaccine may help prevent pertussis that can be then transmitted to patients, but it's not clear if it's adequate protection for the health care worker who later gets exposed to pertussis," says Melanie Swift, MD, medical director of the Vanderbilt Occupational Health Clinic.

Reference

1. Weber DJ, Rutala WA. Management of healthcare workers exposed to pertussis. Infect Control Hosp Epidemiol 1994: 15(6):411-415.