Elsevier

Vaccine

Volume 40, Issue 48, 15 November 2022, Pages 6956-6962
Vaccine

The decline in immunity and circulation of pertussis among Chinese population during the COVID-19 pandemic: A cross-sectional sero-epidemiological study

https://doi.org/10.1016/j.vaccine.2022.10.020Get rights and content

Highlights

  • We conducted the serological investigation of Bordetella pertussis in among populations of different ages in China during the COVID-19 pandemic.

  • To the best of our knowledge, this is the first study to evaluate the immunity of pertussis with anti-PT, anti-FHA, and anti-PRN antibodies in China.

  • The prevalence of pertussis had decreased during the COVID-19 pandemic, but there was still a certain proportion of adolescents and adults exhibiting evidence of recent pertussis infection.

  • The waning of antibody levels after pertussis vaccination were occurred, and an extra booster dose is highly recommended at the age of 6 years by replacing DT with DTP.

Abstract

Background

In recent years, the resurgence of pertussis has posed a public health challenge in many countries. This study aimed to evaluate the immunity levels against pertussis among populations of different ages in China.

Methods

We conducted a cross-sectional serological survey in Zhejiang Province, China in 2020. Serum IgG antibodies against pertussis toxin (anti-PT), filamentous hemagglutinin (anti-FHA), and pertactin (anti-PRN) were quantitatively measured. The geometric mean concentration (GMC) of three antibodies was calculated. An anti-PT level < 5 IU/mL was considered undetectable, ≥20 IU/mL as seropositive and ≥80 IU/mL as an indicator of recent infection. Mathematical models were fitted for anti-PT concentrations over time in children after four doses of the pertussis vaccination.

Results

A total of 4459 participants aged 0–59 years were included in the analyses. The overall positivity rate of anti-PT was 29.80% with the highest (81.44%) rate in the 1–2 years old and the lowest (4.72%) in 10–14 years old. The GMCs of anti-PT, anti-FHA and anti-PRN for the whole participants were 9.67 (95%CI: 9.25–10.10),18.93 (18.24–19.67), and 8.99 (8.61–9.38) IU/mL, respectively. Over 50% of subjects aged ≥ 7 years had undetectable anti-PT IgG antibodies (<5IU/mL). The proportions of the populations with anti-PT IgG ≥ 80 IU/mL were approximately 0.9%, 0.3% and 1.1% among the 10–14, 15–29, and 40–59 years old groups, respectively. The power regression equation of the attenuation model after last dose of pertussis vaccine was y = 41.088x-1.238 (R2 = 0.935, p < 0.001). The fitted anti-PT concentrations was only 5.60 IU/mL at 5 years following the last vaccination dose.

Conclusion

The prevalence of pertussis decreased during the study period in the COVID-19 pandemic; however, there was still a certain proportion of adolescents and adults with evidence of recent infection. The decline in antibody levels after pertussis vaccination was observed, and booster doses are in urgent need in China.

Keywords

Pertussis
Vaccine
Seroprevalence
Antibody

Data availability

Data will be made available on request.

Cited by (0)

1

These authors contributed equally to this work.

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