Pertussis immunization for adolescents: What are we waiting for?

Strategic Approaches Towards Pertussis Control in Oman

Objectives

Pertussis is a highly contagious disease that causes severe and serious symptoms among infants and young children with fatalities observed in early infancy. The disease is milder among adolescents and adults. In this paper, we describe the progress made towards pertussis control in Oman and the challenges ahead to achieve control and maintain it.

Methods

Pertussis data were collected between 1981 and 2015 from various sources including Annual Health Reports, annual Ministry of Health progress reports, and Community Health and Diseases Surveillance Newsletter, which provided information for the calculation of different pertussis indicators.

Results

Diphtheria-tetanus-whole cell pertussis 3 (DTwP3) vaccination coverage rose from 19% in 1981 to 97% in 1992 and has been at ³ 97% until 2015. The overall incidence of pertussis dropped dramatically from an average of 771 cases per 100 000 population from 1981 through 1985, to 21 cases per 100 000 population between 2011 and 2015 (p < 0.001). Since 1987, pertussis cases were cyclical, with peaks every three to five years with three major outbreaks reported in some parts of the country. Between 2011 and 2015, 831 cases were notified of which 785 (94.4%) met the pertussis case definition. Of these 785 cases, 625 (79.7%) were in children aged < 12 months (average rate 185 per 100 000 population), and almost all were hospitalized. Of the 625, 357 (57.1%) were aged < 2 months (average incidence of 600/100 000 population), 129 (20.6%) were 2-3 months old (average incidence of 202/100 000 population), 80 (12.8%) were 4-6 months (average incidence of 119/100 000 population), and 59 (9.4%) were 6-12 months old (average incidence is 22/100 000 population). There were 160/785 (20.3%) cases reported in children ³ 12 months old (average rate 4/100 000 population). Downward trend rates were reported in the 5-14 year age group and a very low disease rate was observed in the > 15 years group. Since 2007, no deaths recorded were attributed to pertussis.

Conclusions

Oman has a high coverage of DTP3; however, pertussis control remains a challenge among infants < 12 months old. Therefore, tetanus, diphtheria, and acellular pertussis (Tdap) vaccination of pregnant women is likely to be the best strategy for preventing the disease in infants.

Immunogenicity of Pertussis Booster Vaccination in Children and Adolescents with Inflammatory Bowel Disease: A Controlled Study

BACKGROUND

There are limited data on antibody response to vaccination in patients with inflammatory bowel disease (IBD). In this study, we aimed to assess the immunogenicity of a booster dose of pertussis vaccine in pediatric patients with IBD and to compare their response with healthy controls.

METHODS

We performed a multicenter, prospective, and controlled trial. Eligible for inclusion were children and adolescents (11-18 year olds), with no history of pertussis booster immunization after the age of 6 years or history of pertussis. Study population was divided into 4 groups: patients with IBD receiving no immunosuppressive therapy (group 1), those on thiopurines only (group 2), those on thiopurines and TNF-α agents (group 3), and healthy controls (group 4). Patients and controls received 1 dose of pertussis vaccine intramuscularly and were asked to record adverse effects for 3 days after vaccination. The primary outcome measure was adequate vaccine response, defined as the concentration of anti-Bordetella pertussis antibodies >11 μg/mL, measured between 4 and 8 weeks after the vaccination.

RESULTS

In total, 138 subjects (111 patients and 27 controls) were enrolled in the study. Rates of adequate vaccine response did not differ among the 4 study groups (P = 0.11). Moreover, those patients with IBD who were on immunosuppressive therapy did not differ from those who were not (90.6% versus 88.2%, P = 0.37). No serious adverse effects in relation to the administration of vaccine were noted.

CONCLUSIONS

Booster dose of pertussis vaccine was immunogenic and safe in pediatric patients with IBD.

Comparison of the safety and immunogenicity of concomitant and sequential administration of an adult formulation tetanus and diphtheria toxoids adsorbed combined with acellular pertussis (Tdap) vaccine and trivalent inactivated influenza vaccine in adults

The annual contact for influenza vaccination provides an opportunity to ensure that adults have received other recommended vaccines such as Tdap. Healthy 19-64 year-olds were randomized to receive concomitant administration of Tdap and influenza vaccines or influenza vaccine followed (in 4-6 weeks by) Tdap. 720 participants were enrolled. No clinically relevant between-group differences were observed in the rates or severities of erythema, swelling, or pain at the Tdap injection site. Injection-site pain was the most commonly reported adverse event (66.6% concomitant administration group versus 60.8% sequential administration group); most pain was graded as mild and resolved by day 3. Seroprotection and seroresponse rates for all influenza strains were comparable between the two groups. For diphtheria and tetanus, seroprotection rates and post-vaccination GMTs were non-inferior in the concomitant administration group compared to the sequential administration group. A trend for lower antibody responses to pertussis antigens PT, FHA, and FIM was observed after concomitant administration and, for PRN, this difference failed the non-inferiority criteria. While there is a small diminution in antibody response to tetanus and pertussis antigens, concomitant administration of Tdap and influenza vaccine was well tolerated and immunogenic and may offer practical advantages including convenience, compliance, and cost-savings.