Vaccines protect individual children against infectious diseases and prevent disease outbreaks in the population. Most children in the United Kingdom are vaccinated on time, but some are vaccinated late or miss getting vaccinated. It is important that all children get all their recommended vaccines, at the recommended ages. For example, not enough children in England have been getting two doses of the Measles, Mumps and Rubella(MMR) vaccine recently, causing more measles outbreaks. Vaccines may also reduce the risk of children becoming ill from other illnesses as well as preventing specific infectious diseases.
Our research aims to understand which children in England are unvaccinated, if children whose mothers are vaccinated in pregnancy are more likely to get vaccinated and how vaccines benefit long-term health. We will use a database of anonymous GP records called the Clinical Practice Research Datalink(CPRD) in three studies. We will track the GP visits of babies born between 2000-2017.
- Study-1, will describe which children are vaccinated late or miss getting vaccinated. For example, how vaccination is different between children living in areas that are less affluent and from different ethnic groups.
- Study-2, will link mothers and childrens GP records to see if mothers of unvaccinated childrens are less likely to receive pregnancy vaccines.
- Study-3, will measure if being vaccinated means children visit their GP less and are prescribed less antibiotics.
Our findings could help increase the number of children getting vaccinated and provide information for parents and doctors about how vaccines benefit long-term child health.
This original study period will now be extended to include the period of the Covid-19 pandemic. This aims to understand the impact of Covid-19 on childhood and pregnancy vaccine uptake and childrens primary care use.
Background: Englands 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 mothers and childrens 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 childrens 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 mothers and childrens 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 childrens 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.
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).
Sonia Saxena - Chief Investigator - Imperial College London
Helen SKIRROW - Corresponding Applicant - Imperial College London
Ceire Costelloe - Collaborator - Imperial College London
Mark Cunningham - Collaborator - Imperial College London
Sonia Saxena - Collaborator - Imperial College London
CPRD Mother-Baby Link;Patient Level Index of Multiple Deprivation