Responses to pertussis vaccination in patients with COPD

In a recent prospective longitudinal study published in Scientific reportsresearchers assessed humoral and cellular immune responses to pertussis vaccination in patients with chronic obstructive pulmonary disease (COPD).

Study: Immune response to pertussis vaccine in patients with COPD. Image Credit: VadiFuoco/Shutterstock.com

Background

COPD, characterized by chronic lung inflammation that impairs lung immunity, increases an individual’s susceptibility to all lung infections. The exacerbated decline in lung function leads to significant morbidity and mortality in patients with COPD.

In one of their previous studies, the researchers found a decreased immunological response to seasonal flu vaccination in patients with COPD. This raises the possibility that other vaccines may also be less effective in patients with COPD. Thus, disease prevention strategies aimed at preventing infections could be at play, raising public health concerns.

whooping cough, caused by Bordetella pertussis, is an acute respiratory infection for which acellular pertussis (aP) vaccine is available. Recently, cases of whooping cough have resurfaced in adults over 65 in the United States.

The majority of these cases, i.e. more than 26%, occurred in COPD patients, thus necessitating an evaluation of the efficacy of aP vaccination in COPD patients.

About the study

In the present single-center study, researchers recruited eight healthy volunteers and 13 patients with stable COPD between September 2018 and May 2019 from a pulmonary outpatient clinic at Henri Mondor Hospital in France.

Patients had no history of exacerbation of lung function or respiratory infection in the month prior to the start of the study. In addition, they met the eligibility criteria to receive the diphtheria-tetanus-polio-pertussis (Tdap) vaccine.

First, the team administered a single dose of Tdap intramuscularly (day zero). They asked all participants to come and donate a blood sample on days zero (before vaccination), seven, 15 and 30 after vaccination.

Next, the researchers looked at the humoral immune response on days zero and seven, specifically T-follicular helper (Tfh) cells and plasmablasts. Additionally, they measured pertussis antibody titers in serum using blood samples taken on days zero and 30.

The team used intracellular cytokine staining to assess specific T-cell responses using samples taken 15 days after vaccination. To this end, they ex-living stimulated peripheral blood mononuclear cells (PBMC) with a B. whooping cough peptide pool. The team also analyzed the supernatants of the stimulated cells.

Results

The 13 COPD patients and eight controls had a median age of 68 and 64 years, respectively. There were six and 12 men in the healthy volunteers and the COPD group, respectively. As expected, COPS patients had lower forced expiratory volume in 1 s (FEV1) and lower forced vital capacity (FVC), 57% versus 102% and 77% versus 101%.

The study data showed that in patients with COPD, the pattern of immune response to pertussis vaccination was in stark contrast to influenza vaccination. The researchers cited a few possible reasons for the observed discrepancy.

First, the prevalence of pertussis infections is lower than that of influenza infections, possibly due to the success of its vaccination programs, which have resulted in less exposure to pertussis antigens.

Second, the Tdap vaccination schedule typically involved fewer doses, reducing opportunities for immune priming and developing original antigenic sin (OAS) effects. Third, this is also possible due to differences in vaccine design and composition of vaccine adjuvants for the two diseases.

Accordingly, the authors noted no marked differences in circulating B cells, the group of 4+ and CD8+ differentiating T cell (CD) subsets, and TFH cells. However, they observed an increase in the number of naïve B cells and a decrease in the number of memory B cells in patients with COPD.

Additionally, there was a significant increase in TFH and plasmablasts on the seventh day after vaccination, suggesting successful induction of the humoral response. In addition, both groups had comparable pertussis-specific antibody levels 30 days after vaccination.

Within 15 days of vaccination, pertussis-specific CD4+ T cells were equivalent in the two groups, as quantified by staining for interferon gamma, interleukin-2, and tumor necrosis factor alpha.

Conclusion

In summary, the study data confirmed that COPD patients are no less responsive to all vaccinations. Although they are generally vulnerable, they have developed a very effective immunological response to pertussis vaccination.

Thus, clinicians should consider providing ten-year Tdap boosters to patients with COPD.