Late or missed childhood vaccination: identifying the determinants and estimating the impact on subsequent child health outcomes

Date of Approval
Application Number
20_010
Technical Summary

Background: England’s overall high vaccination rates are declining putting individual children at risk of infectious diseases. For example, recent variable measles, mumps and rubella(MMR) vaccine uptake caused by missed and late vaccination has contributed to increased measles outbreaks. Vaccine uptake is related to health system barriers and parental attitudes, with lower uptake among some ethnicities and poorer children. Pregnant women are offered pertussis vaccine, but the relationship between mother’s and children’s vaccine uptake is unknown. There is evidence that vaccines benefit overall child health beyond preventing specific infections. However, the impact of missed or late vaccination on subsequent primary-care use and antibiotic prescribing is unknown.

Research Questions

1.Which children are at risk of being vaccinated late or missing vaccines before 5 years old?

2.Do children whose mothers are not vaccinated in pregnancy have a higher risk of being vaccinated late or missing vaccines before 5 years old?

3.Do children who are vaccinated late or who miss vaccines before 5 years old have higher annual rates of primary-care consultations and antibiotic prescribing?

Methods: Three, retrospective birth cohort-studies are proposed:

Study-1:will describe children’s vaccination patterns: before 1 year, at 1 year and before 5 years. Vaccination patterns will be described by sex, ethnicity, deprivation, prematurity, breastfeeding, congenital co-morbidities and chronic illnesses.

Study-2:will link mother’s and children’s records to estimate the association between maternal pertussis vaccination and childhood vaccinations using a multi-nominal logistic regression model.

Study-3:will estimate the impact of late or missed vaccination on primary care consultation and antibiotic prescribing rates using a Poisson regression model, stratified by age-group.

Impact:Findings will inform how children’s vaccine services can improve to increase vaccine uptake and protect more children against infectious diseases.

The study period will be extended to include children born beyond the original study cohort definition and include those born up until 31 December 2020.

Health Outcomes to be Measured

Study 1
• On time or early vaccination
• Late vaccination
• Missed vaccination
• Missed MMR vaccination

Study 2

Same as study 1

Study 3

Primary Outcomes
• General Practice Consultation Rates
• General Practice Illness Consultations Rates
• General Practice Infective Illness Consultations Rates

All consultation types will be included: face-to-face or phone, GP or nurse practitioner.

Secondary Outcomes
• General Practice Acute Antibiotic Prescriptions rates.
• General Practice Antibiotic Prescriptions associated with Infective illness consultations rates (3).
• Vaccine Preventable Disease rates (Measles, Mumps, Rubella, Pneumococcal disease, Meningococcal type C, Pertussis). Other vaccine preventable disease outcomes not included due to rarity(29).

Collaborators

Sonia Saxena - Chief Investigator - Imperial College London
Helen Skirrow - Corresponding Applicant - Imperial College London
Ceire Costelloe - Collaborator - Imperial College London

Linkages

CPRD Mother-Baby Link;Patient Level Index of Multiple Deprivation