COVID-19 and regional inequalities in childhood vaccination uptake in England: a spline regression

In recent years, the uptake of childhood vaccinations before the age of five has declined globally. In England, the decline in measles, mumps, and rubella (MMR) vaccination coverage is concerning and has subsequently been followed by an increase in measles outbreaks. This study analysed the sustained and additional impact of the COVID-19 pandemic on area-level inequalities in childhood vaccination uptake across regions in England.

Spline regressions with three-way interaction terms were used to assess the impact of COVID-19, from the first lockdown, on local authorities across regions and deprivation quartiles. Cover of Vaccination Evaluated Rapidly data was used for the uptake statistics, and the Indices of Multiple Deprivation 2019 for the deprivation quartiles. The lowest coverage vaccines were analysed: the pre-school booster (one dose) and MMR (two doses, cumulative) from July - September 2014 to October - December 2022.

The findings suggest the odds of childhood vaccination uptake were declining in England prior to the first lockdown, but there was an additional decrease associated with this event by 12% (OR:0.88, CI:0.79-0.99, p < .05) for the pre-school booster and 13% (OR:0.87, CI:0.77-0.99, p < .05) for the MMR vaccine. For local authorities classified as the most deprived 25% (Quartile 1), there was a 15% (OR: 0.85, CI: (0.72-0.99, p < .05) post-lockdown-associated decline in the odds of MMR uptake, but not the pre-school booster. Post-lockdown and region interaction effects for the pre-school booster were as follows: Yorkshire and the Humber, 39% decreased odds (OR:0.61, CI:0.54-0.68, p < .001); East Midlands, 22% decreased odds (OR:0.77 OR, CI:0.62-0.95, p < .05); and West Midlands, 19% increased odds (OR:1.19, CI:1.00-1.40, p < .05). For the MMR vaccine, these were: Yorkshire and the Humber, 41% decreased odds (OR:0.59, CI:0.52-0.67, p < .001); North West, 30% increased odds (OR:1.3, CI:1.04-1.64, p < .05); West Midlands, 21% increased odds (OR:1.21, CI:1-1.46, p < .05); and South East, 19% decreased odds (OR:0.67, CI:0.98, p < .05). Evidence of three-way post-lockdown interaction effects for deprivation quartile and region was also identified for both vaccines.

The results highlight the need for national vaccination uptake analyses to consider regional variation, as similarly deprived local authorities do not necessarily exhibit the same COVID-19-associated effects.