Today, we’re speaking to Dr Karol Basta, a Public Health Registrar based in London.
Title of paper: Predictors of Childhood Vaccination Uptake and Timeliness in a Diverse Urban Population
Available at: https://doi.org/10.3399/BJGP.2025.0319
Childhood vaccination rates have declined in the UK, with inequalities in urban, deprived, and ethnically diverse populations. Previous studies have lacked individual-level clinical data or did not explore both uptake and timeliness. We analysed 13 years of routinely collected primary care data for over 37,000 children in a diverse London borough to identify predictors of uptake and timeliness. Distinct sociodemographic and clinical factors were associated with incomplete and delayed vaccination, offering timely insights as responsibility for vaccination services shifts closer to local systems and place-based commissioning.
Transcript
This transcript was generated using AI and has not been reviewed for accuracy. Please be aware it may contain errors or omissions.
Speaker A
00:00:00.880 - 00:00:52.000
Hi and welcome to BJJP Interviews. I'm Nada Khan and I'm one of the associate editors of the Journal. Thanks for taking the time to listen to this podcast today.
In today's episode, we're speaking to Dr. Carol Basta.
Carol is a public health registrar based in London and we're here to talk about the paper she's recently published here in the bjgp, which is titled Predictors of Childhood Vaccination Uptake and Timeliness in a Diverse Urban Population. So, hi, Carol, it's really lovely to meet you and to talk about this work. And I guess just to start, I wanted to put this work into context.
We know that in the uk, overall childhood vaccination rates have unfortunately been declining. Could you talk us through some of the current challenges around vaccination, especially in urban and diverse areas?
Speaker B
00:00:52.720 - 00:02:06.750
Yep. So we know vaccinations are really powerful and cost effective tools we have in giving children the best start in life life.
But unfortunately, in the UK, since 2012, the uptake has been declining and actually since 2021, none of the vaccines in England have reached the 95% target recommended by the WHO to stop communicable disease outbreaks. And the kind of negative consequences of this aren't just sort of future hypothetical risks.
We've already been seeing vaccine preventable diseases such as measles and whooping cough resurgences, and this is especially in certain parts of the uk, such as London or the northwest of England. So no uptake of vaccines is decreasing and vaccine preventable diseases are increasing. But that's not the full picture.
We also know, for example, following work done by, at the time, Public health England in 2017, there are avoidable inequalities across the childhood vaccination program nationally, for example, linked to deprivation, geography and ethnicity.
However, what was missing was really kind of contemporary granular evidence on the social and clinical factors associated with unequal vaccine outcomes, especially in diverse urban environments.
Speaker A
00:02:06.990 - 00:02:16.670
And I know this was highlighted as well during COVID but there is a mistrust of health services amongst some communities as well, which might be playing into this.
Speaker B
00:02:17.470 - 00:03:11.120
Yeah, exactly.
So at the time when I was working in Lamb of Council, we knew qualitatively from talking to our community and talking to our local GP partners, that there was kind of sense of rising mistrust in healthcare services, but also rising difficulties with actually access to services.
And that doesn't just affect whether or not people can get the vaccine, for example, it also affects whether they can have conversations about vaccines and the kind of continuity of care and building up those relationships.
And so this is what we had kind of on a local level, but we knew that there was also national feelings and sentiments around mistrust, not just national, but actually globally vaccination mistrust from the COVID 19 pandemic. And there were worries that this had run off into the childhood vaccination program as well, that it hadn't just confined itself to Covid vaccines.
Speaker A
00:03:11.440 - 00:03:41.490
So this was a study looking at predictors of routine childhood vaccination from 40 general practices in Lambeth and London, which is a pretty ethnically and socioeconomic demographically diverse borough. And you looked here at the vaccination uptake and timeliness and some of the predictors for these. This was a really big sample.
But just to underline the population here, tell us more about the demographics in Lambeth as a borough in terms of ethnicity, because that's where you were based when this work was done.
Speaker B
00:03:41.890 - 00:04:32.250
Yeah, exactly.
So Lambeth is an inner London borough and it is very ethnically diverse, it's very densely populated, but it also has some of the highest levels of deprivation in the country. And part of the strengths of this study is that we were able to use detailed ethnic subgroup breakdowns.
So, for example, rather than using the broad category of South Asian, we were able to split this down into Pakistani, Bangladeshi, Indian, et cetera. And this was really important because this aligns with national health equity guidance.
We know that health outcomes actually vary between the details, subgroups.
There's some evidence to suggest that, but it was also important following local community engagement work, where people repeatedly told us these kind of big, broad groups don't reflect how we self identify.
Speaker A
00:04:32.490 - 00:04:39.530
And I wanted to just move on to the results here, so can you start talking us through some of the associations based on deprivation to start with?
Speaker B
00:04:39.690 - 00:06:22.410
Yeah, sure. So we looked at two main outcomes.
We looked at vaccination uptake, so that's whether children had received their vaccines at any time point during the study. And we also looked at vaccination timeliness.
And vaccination timeliness is important because although a child might eventually go on to receive their vaccine, it leaves them. They're late, it leaves them unprotected for at times when they're most potentially likely to get unwell.
And what we found with deprivation in uptake, there was really clear patterns associated by deprivation.
There was actually children living in more deprived areas were progressively less likely to be vaccinated compared with those living in the least deprived areas.
So, for example, children living in the most deprived 20% of our population were about a third less likely to be fully vaccinated compared to those living in the least deprived areas. This kind of wasn't just a straight out deprivation.
There was also lower uptake linked to other markers of social vulnerability, such as being born outside of eco, or such as children having safeguarding involvement. And so that was what we found for uptake. But what was interesting is the findings for timeliness didn't mirror this.
So whilst those living deprivation were less likely to be vaccinated, if we zoom in on just the population that were vaccinated and think about were they vaccinated on time, we didn't find that children living in deprivation were less likely to be vaccinated on time. We found no difference. And there was a similar pattern for other markers of social vulnerability, such as safeguarding involvement.
They have a lower uptake, but it wasn't associated with kind of untimely vaccination.
Speaker A
00:06:22.650 - 00:06:31.210
And you've touched upon this, but there was a really striking result here in terms of children who were born outside of the uk. So can you talk us through this?
Speaker B
00:06:31.530 - 00:06:59.060
Yeah. So we also found that children born outside of the UK were much less likely to be vaccinated compared to children born inside the uk.
However, if again, we zoom in on just those vaccinated and look at timeliness, we actually find the opposite. So if you were born outside of the uk, you were more likely to have your vaccine delivered on time compared to those who were born in the uk?
Speaker A
00:06:59.380 - 00:07:03.380
Sure, yeah. So talk us through some of the reasons that you think that this might be happening.
Speaker B
00:07:03.380 - 00:08:30.800
Yeah, I think these findings, the difference between uptake and timeliness, not having the same predictors and in some case having the opposite patterns being shown are really quite interesting. And they're kind of a few possible explanations as to why this might be. One is perhaps potentially there's a form of selection going on.
So when we look at only children who get vaccinated in groups with lower overall uptake, for example, children of non white British ethnicity, or as we've said, children not born in the uk, the children who do get vaccinated may represent more engaged, health literate or well supported families. And that same engagement may...