The potential for a large outbreak of measles
The ranking scores for first and equal second place were very close (Fig. 1). The highest-ranked concern was the potential threat of a large outbreak of measles, followed by prioritising the isolation of infected children and protecting the most vulnerable community members, which were ranked equal second. The highest ranked option was ‘the potential for a big outbreak’, while the lowest ranked overall was ‘not being able to identify the source’, both receiving over 50% of the highest (first) and lowest (fifth) rankings respectively. Options 2–4 were more evenly spread (see supplementary graph, additional file 2).
In Round 3, the respondents indicated strongly that they agreed with these rankings, with 21/24 agreeing or strongly agreeing with the way these concerns had been ranked in the prior round. In their comments, Delphi participants noted that they agreed with the ranking of priorities because the focus is on reducing the risk of transmission and protecting vulnerable members of the community:
Sensible ordering of concerns – emphasis on protecting people, especially vulnerable people.
(Respondent with regional sphere of responsibility)
It follows principles of public health response - which focuses on the risk of transmission and preventing this and focuses on the highly vulnerable group who are unable to protect themselves but are more likely to have severe disease outcomes.
(Respondent with local sphere of responsibility)
Commenting on the importance of stopping the spread of the disease, several participants mentioned that parents are usually fairly compliant when it comes to isolating infected children:
The rankings generally reflect my concerns and their priority. I agree (rather than strongly agree) with rankings because my experience is that generally the families of known affected children are generally compliant with advice about isolation.
(Respondent with regional sphere of responsibility)
In my experience parents comply with isolating children once advised. Vaccine refusers are particularly compliant perhaps because they understand the implications to their position if they don't and are responsible for further transmission.
(Respondent with state sphere of responsibility)
The small number of participants who indicated they disagreed with the ranking did so because they believed that the priorities and concerns overlap, for example:
Many of these issues are simply different facets of the same fundamental challenge. They are all strongly linked. But a big outbreak is the consequence of concern and the other issues are either drivers or barriers or smaller scale issues. So I agree but all responses are really valid concerns!
(Respondent with state and national spheres of responsibility)
There did not appear to be a patterned difference in responses to the question about key concerns between participants who held positions of national, regional or local levels of responsibility. The small number of respondents who disagreed or chose neither agree nor disagree, commented that the threat to vulnerable community members and containing the spread of the disease (by isolating those affected) should be higher priority. For example:
This degree of clustering of under vaccinated children is unusual and requires long term action, but not as urgently as concerns about spread and need for isolation of cases.
(Respondent with regional sphere of responsibility)
Just because there may be parents who do not wish to vaccinate their children doesn't mean they would not engage in isolating their infected child. I think point 3 and 4 should be higher in rank.
(Respondent with state sphere of responsibility)
I believe ‘The threat to the vulnerable/immunocompromised’ should be of most concern as this is the group who most ‘benefits’ from Herd Immunity.
(Respondent with local sphere of responsibility)
Isolating infected children
Participants in Round 2 were asked to rank the most common responses to the question: What would be your priority for the non-vaccinating or unvaccinated members of your community in this scenario? Fig. 2 shows that isolating or quarantining infected children was the highest ranked priority, however support for the other options was more evenly spread.
The highest ranked priority for the non-vaccinating and unvaccinated, ranked number one by over 60% of participants, was isolating infected children. Options 2–6 were ranked more evenly (see supplementary graph, additional file 3). When reflecting on the high priority of isolating infected children, Delphi panel members emphasised that the most important thing to do was to minimise the potential for the spread of the disease. For instance:
Need to isolate and contact tracing to reduce further spread.
(Respondent with local sphere of responsibility)
The biggest priority is minimising the spread of measles in a largely unvaccinated population. Isolating and quarantining will be more effective in the short term. Vaccination is important but takes longer to be effective.
(Respondent with local sphere of responsibility)
Education was ranked second, with participants outlining that it was important for this community to be educated about the risks of not vaccinating and to keep them informed about what signs and symptoms to look out for:
Also need to do a lot of education about recognising the symptoms of measles, self-isolation and presentation to healthcare early in course of illness for testing.
(Respondent with state sphere of responsibility)
Interestingly, checking immunisation status was ranked the lowest. When asked to comment on why they thought: “Media and social media communication campaign” and “Checking immunisation status” were both ranked lower priorities than the other options, panellists suggested that other priorities in the list are a more urgent during an outbreak. They also noted it was likely that all options would happen simultaneously and that in an outbreak situation the priority target populations are those infected or in contact with the disease. For example:
These are both equally important measures but obviously not 1st response.
(Respondent with local sphere of responsibility)
These can both happen down the track – It is not a priority.
(Respondent with local sphere of responsibility)
Both media communication and checking immunisation status are broader, ‘slower’ and less targeted interventions. The key populations to target to mitigate or prevent a large outbreak are the cases and contacts.
(Respondent with state and national spheres of responsibility)
It depends on what the media campaigns are targeting, if it is for public awareness regarding an outbreak then the priority should be higher but if it is trying to improve vaccination rates in a population that already has very strong preformulated opinions on vaccination it is not going to make much of a difference and therefore a lower priority.
(Respondent with local sphere of responsibility)
Even though our results indicate that participants ranked a wider range of concerns as being key priorities, the tier of operational responsibility does not appear to have influenced their responses to this question.
Encountering (and countering) mistrust
In Round 1 we asked participants to outline the practical issues they would face in an outbreak, relating to the non-vaccinating community. Common responses included: mistrust, the need for communication, difficulties in isolating/excluding, the strong negative sentiment regarding vaccination. The following quotes illustrate the dominant themes arising from the first round of the survey:
Misinformation about VPDs [vaccine preventable diseases] and vaccines and mistrust in health professionals.
(Respondent with local and regional spheres of responsibility)
The need for a rapid response and the tension between this and the need for an iterative, engaged, nuanced communication with individual families and others.
(Respondent with State sphere of responsibility)
Enforcing isolation during incubation period - especially if they are a large number in the community and their concern of loss of income having to take sick leave, etc.
(Respondent with local sphere of responsibility)
The highest ranked practical issue faced by Round 2 participants was encountering mistrust from the non-vaccinating members of the community. Similarly to the previous question, the rankings for the other options were relatively evenly spread. Figure 3 indicates the order of importance, as ranked by participants. The relative ranking of responses for this question was more evenly spread than other questions, with all ranked responses being below 35% (see supplementary graph, additional file 4) suggesting that all options are important to the extent that they are different facets of the problem of gaining the trust of and communicating constructively with the non-vaccinating community.
Several respondents talked about the need to combat misinformation about vaccines, but the general consensus was that this kind of public campaign was not high priority during an outbreak. Social media was regularly mentioned in regard to spreading public health information about the outbreak, to educate the public about looking out for symptoms and isolating:
Social media to notify the community of real and inherent danger to the population
(Respondent with regional sphere of responsibility)
Communication and using social media would be next step to enable other vulnerable community groups and those only partially immunised to be offered immunisation or immunoglobulin to prevent them getting infected.
(Respondent with regional sphere of responsibility)
Respondents to Round 3 showed strong support for the rankings provided by the Round 2 panellists, with the majority (18/24) agreeing or strongly agreeing with the rankings outlined in Fig. 3. Two out of 24 neither agreed nor disagreed and 4 out of 24 disagreed. Once again, the participant’s tier of responsibility did not influence their response. In their comments those who did not agree reasoned that it was not productive to pressure people into immunising their children – the focus should be on making them aware of the opportunity to do so. For example:
If we assume non vaccinating community means vaccine refusers rather than vaccine hesitant people, then there is little utility in gaining trust or combatting misinformation to this community. I would be more concerned about anti vaccination messages being spread to non-vaccinated community who are not vaccine refusers.
(Respondent with state sphere of responsibility)
Non vaccinators are well informed and have made a choice. Options for people to change their mind and vaccinate should be easy.
(Respondent with local sphere of responsibility)
A small number of respondents mentioned that they preferred a different ranking of priorities, pointing out that combatting misinformation would be a lower priority than practical things like contacting potentially infected community members. For example:
Mistrust may be present but ought not be presumed to be a limiting difficulty. Providing sound practical information is more important in this setting that trying to dismantle contrary beliefs, and an adversarial approach in this context may even fuel unhelpful ideas.
(Respondent with state sphere of responsibility)
I would rate combatting misinformation etc. lower e.g. below current #5 [“targeted communication and resources”]. Need to reach community members, isolate infected and quarantine exposed before tackling long-held beliefs and misinformation.
(Respondent with regional sphere of responsibility)
In Round 3 we asked respondents to comment on what strategies in their experience have proved the most successful for countering mistrust among non-vaccinating parents during an outbreak. Recurring responses to this question were the need for patience and calm education. Panellists suggested it was important to highlight to parents the serious complications that can arise from the disease. Further, they suggested that it is important not to get into arguments with non-vaccinating members of the community, but instead to be offer reassurance, provide accurate information and to acknowledge different beliefs. For instance:
Not arguing with non-vaccinators and always be truthful in your answers
(Respondent with local sphere of responsibility)
Reassurance, patience, education may help with those people that are still 'sitting on the fence' about vaccination.
(Respondent with local sphere of responsibility)
Recognising and acknowledging people’s beliefs, however conveying facts and not getting drawn into a discussion or arguments. Consistent and clear media messaging.
(Respondent with regional sphere of responsibility)
Practitioners want a willingness to listen and cooperate
In an outbreak scenario ‘contact details and clear contact avenues’ were ranked the most important, in terms of what the panellists would need from the non-vaccinating community. However, it was not ranked significantly higher than 2 and 3: a willingness to listen and consider information, and willingness to follow isolation instructions. The rankings for this question were relatively evenly spread. Notably, ‘consent to immunise their children’ was ranked the lowest (Fig. 4).
The lowest ranked option, with over 50% placing this last, was ‘consent to immunise their children’ (see Additional file 5). Related to the highest concern being the potential for a large outbreak, the need for clear contact tracing avenues and a willingness among non-vaccinating parents to follow isolation instructions and consider information on offer are both vital for public health workers in managing the spread of the disease. Several respondents mentioned that in their experience, cooperation from parents is variable. For example:
Varied responses across the acceptance/refusal spectrum. Some are willing to listen, discuss and maybe vaccinate or partially vaccinate if given the time to discuss and express their concerns. Others would not get into the discussion and indicate that their decisions are final. Cooperation ranges from being willing to engage in a discussion, to partially vaccinate or get a referral to a specialised service.
(Respondent with local sphere of responsibility)
It has varied at different times and in different communities – sometimes they are quite cooperative, other times they have been very evasive/impossible to engage. That may be the reason there is such a variation in responses, if respondents have had only one or two encounters, they may have been very positive or very negative.
(Respondent with state sphere of responsibility)
Importantly, the panel identified the importance of being able to identify and differentiate between “vaccine refusers” and “vaccine hesitant”. They characterised vaccine-hesitant community members as being more likely than vaccine-refusers to listen and cooperate with health authorities. Several pointed out that trying to engage with those who have ‘made up their mind’ is unlikely to help, as the following responses illustrate:
If parents are vaccine refusing, they do not wish to engage in any way. They are not interested in information that does not support their stance. Vaccine hesitant parents are generally cautious and sometimes confronting, but they will at least ask questions and request information.
(Respondent with state sphere of responsibility)
On the rare occasions we engage with non-vaccinating parents we explain the rationale for our views and generally end up agreeing to disagree about vaccination, but they accept requirements for isolation, exclusion.
(Respondent with regional sphere of responsibility)
Limited communication and often confrontational from non-vaccinating community, for those who are just unsure, they are much more open and ask more questions and want discussion.
(Respondent with regional sphere of responsibility)
The need to treat people with respect, be empathetic and listen was also raised by a number of respondents. For example:
The core of non-vaccinators who are intransigent is really quite small - around 1%. Those who are hesitant but non-vaccinating is larger and they are influenced by the core group but open to other trusted individuals, including GPs, nurses and others. The first group are very hard to deal with and should largely be left alone. The latter group takes work but can be cooperative with the right messages and approaches; empathetic, flexible, engaged and listening.
(Respondent with state sphere of responsibility)
Communicating with the community
Panellists made a distinction between vaccine refusers and parents with lots of concerns and questions and suggested that in an outbreak, focusing on the former is not urgent. Respectful conversations about immunisation were seen as important. Respondents acknowledged that there are structural barriers to accessing vaccination, and that different strategies are required for different groups. For instance:
These are the general priorities from my perspective. Of course misinformation via social media is an issue, but it’s a long-term, complex issue and unlikely to be an immediate priority, especially given the fact that it is promulgated by, and engaged with, the most ardent anti-vaxxers. And in this scenario, we really want to reach the ‘hesitant’ and those with logistic, awareness, financial or other challenges to vaccination.
(Respondent with state and national spheres of responsibility)
While some are totally mistrusting of vaccines, not all under-immunised or non-immunised people are due to anti-vaccination. Some just require time the opportunity to ask questions and time to digest the answers. This is often not given in acute or primary health care.
(Respondent with state sphere of responsibility)
Some participants had suggestions for how to best engage with the community during an outbreak, including the need for engaging and positive messages. For example:
Messaging must be tailored, realistic, iterative and emotionally engaging. Finding a trusted ‘broker’ from within the community can be very powerful. A generic, bland, classic ‘government’ FAQ is probably the least effective but may have widest reach. I’m increasingly of the opinion that government engagement via blogs, Twitter, Facebook, open house and other more innovative approaches is probably more robust than website/pamphlet approaches.
(Respondent with state sphere of responsibility)
Focus on delivering positive messages, simple and accurate information and identifying their immediate concerns. Explaining why outbreak has occurred. Potential health issues for their children.
(Respondent with local sphere of responsibility)