Pertussis vaccination campaign among health care workers and validity of recall of previous adverse events following immunization.

BACKGROUND

To minimize Bordetella pertussis transmission, health care workers (HCW) should be regularly vaccinated against pertussis, e.g. every 10 years. Therefore, the previous 2012/2013 vaccination campaign in our hospital was repeated in 2023. Here we describe our findings of the campaign and a nested study on the reliability of recall of adverse events (AE) after 10 years.

METHODS

This was a prospective observational study including all HCW with patient contact. Those who had their last pertussis vaccination ≥10 years ago or with unknown date were offered a booster dose of Tdap (Adacel®) or Tdap-IPV (Adacel-Polio®) vaccine and were asked to report reactogenicity for seven days following vaccination. Those HCW who had participated in the 2012/2013 campaign were asked to report recall of vaccine tolerability back then.

RESULTS

Of 916 eligible HCW, 705 (77.0 %) responded and 191 (27.1 %) of them were not up to date. Of these, 150 (78.5 %) plus 6 who were still up-to-date were vaccinated (Tdap-IPV: N = 91, 58.3 %, Tdap: N = 65; 41.7 %). After the vaccination campaign 684 (74.7 %) of all eligible HCW were up to date with their pertussis immunization status, including 63.4 % of nurses and 76.9 % of physicians. The most common adverse events in 133 (88.1 %) HCW were pain (66.7 %, day two), swelling (27.3 %, day two) and exhaustion (21.5 %, day two). Of 52 HCW who were vaccinated in both campaigns, 13 had ≥ 1 documented AE back in 2012/2013, of which only one remembered that the vaccination had not been well tolerated back then (Cohen's Kappa -0.04 for AE, -0.11 for swelling, -0.03 for redness and 0 for fever).

CONCLUSION

We achieved an up-to date pertussis vaccination status in the majority of HCW. However, vaccinating all eligible HCW remains challenging in the absence of mandatory immunization. The recall of previous AE following immunization was poor.