Though there are signs of gradual improvement, healthcare workers are still woefully underimmunized against pertussis, putting vulnerable patients such as infants at risk, the CDC reports.

“We want all healthcare workers up to date with their Tdap vaccine, but especially those who work and interact with young infants,” says Jennifer L. Liang, DVM, MPVM, a co-author of the study1 and a medical epidemiologist in the CDC Division of Bacterial Diseases. “They are too young to even begin receiving the vaccination.”

As employee professionals are aware, the CDC recommends that healthcare workers be vaccinated with Tdap (tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis) to protect themselves and vulnerable patients. The CDC study assessed Tdap vaccination coverage in healthcare workers surveillance for the years 2012-2014, the most recent data available. The internet panel surveys revealed Tdap vaccination coverage among healthcare personnel (HCP) was 34.8% in 2012; 40.2% in 2013; and 42.4% in 2014, Liang and co-authors report.

“Nurse practitioners/physician’s assistants, physicians, nurses, and HCP working in hospitals and ambulatory care settings had higher Tdap coverage,” they concluded. “Having contact with an infant aged 6 months or less and influenza vaccination receipt were associated with increased Tdap vaccination. Non-Hispanic black race/ethnicity, having an associate/bachelor’s degree, being below poverty, nonclinical personnel status, and working in a long-term care setting were associated with decreased Tdap vaccination.”

The risk of pertussis among HCP is 1.7 times higher than that of the general adult population. Another argument for vaccination and prevention is that pertussis outbreaks can be very expensive. One outbreak that included infants and 10 healthcare workers cost the hospital almost $100,000.2

“Based on the findings, we see that most healthcare personnel are not receiving the Tdap vaccination, which leaves them vulnerable to getting pertussis and spreading it to their patients,” Liang says. “We’re hopeful that we will continue to see the trend increasing, and we encourage employee health professionals to have strategies in place similar to what they do with flu vaccine campaigns to help increase coverage.”

To prevent pertussis in healthcare settings, the CDC recommended in 2005 that HCP receive a single dose of Tdap vaccine at an interval as short as two years from the last dose of tetanus and diphtheria toxoids (Td). In 2011, the CDC expanded the Tdap recommendations to all healthcare workers, regardless of age and time since their most recent Td vaccination. Some confusion about the guidelines may be part of the reason for the low uptake of vaccine, the CDC concedes.

“A booster is not recommended at this time,” Liang says. “The recommendation is that healthcare workers receive one dose of the Tdap vaccine. At this time, it is a one lifetime dose. The one exception is pregnant women. They should have a Tdap vaccine every pregnancy.”

In that regard, the CDC encourages healthcare workers to remind pregnant women to get Tdap as they interact with them in the health system.

“The reason is that while the mother is pregnant she is giving these babies maternal antibodies, so the infants are born with protection,” Liang says.

A bacterial pathogen, pertussis is spread by respiratory droplets. In the WWII era, prior to the wide availability of pertussis vaccines, some 200,000 people in the U.S. were infected annually and some 9,000 died, the CDC reports. Currently, pertussis cases annually are in the range of 10,000 to 40,000 cases annually, with some 20 deaths.

“In the U.S., we have been observing an increase in the number of cases of pertussis since the 1980s,” Liang says. “There are many factors that are contributing to this increasing number of cases. We have very high coverage of people who are vaccinated with the pertussis vaccine, especially among young children and adolescents, so we don’t think this is due to undervaccination. One of the things we are observing is that the vaccines provide protection, but the [efficacy] does wane over time, so it is not providing as long of protection as the vaccine that we used to use in the U.S.”

In the 1990s, acellular pertussis vaccines like Tdap replaced the old whole cell vaccines, which had longer efficacy but raised concerns about side effects. Due in part to concerns about waning immunity, even healthcare workers immunized for Tdap may warrant post-exposure prophylaxis with antibiotics after a pertussis exposure.

“The vaccine status is not part of the consideration in terms of whether they receive antibiotics because of an exposure,” she says. “The length of the time they receive it would depend on the antibiotic. I think the most common antibiotic [PEP regimen] that is prescribed is azithromycin for five days.”

REFERENCES

  1. Srivastav A, Black CL, Lu P, et al. Tdap Vaccination Among Healthcare Personnel, Internet Panel Survey, 2012–2014. Am J Prev Med 2017; May 23. [Epub ahead of print].
  2. Yasmin S, Sunenshine R, Bisgard KM, et al. Healthcare-associated pertussis outbreak in Arizona: challenges and economic impact. Jrl Ped Infect Dis 2011;3:81–84.