"Immunisation programmes can better respond to vaccine hesitancy if their communication tools are informed by socioecological models. These models also provide an opportunity for further research to address communication challenges in a hyperconnected, globalised world."

Factors underlying the acceptance or hesitancy of a vaccine (both for children and adults) can vary in different settings. Pakistan, still a polio-endemic country, has a history of vaccine hesitancy, rooted in the decades-old fight against terrorism. For the COVID-19 vaccine, the country also had to struggle for adequate doses - a factor that could cut people's enthusiasm. Yet, Pakistan vaccinated nearly 70% (160 million) of its population in just over 1 year. This paper asks: How did the country achieve this, and what was the role of communication? It shares insights from Pakistan for policymakers who focus on the demand side of vaccine programmes with the aim of contributing to the global discourse on improving vaccine confidence and bolstering global health security.

The paper opens by exploring Pakistan's unique context, including challenges with regaining vaccine confidence in the wake of past occurrences, including:

• A fake immunisation campaign in 2011, which was followed by consistent killing of vaccine workers;
• A fake-news-inspired incident during the national immunisation campaign in April 2019 in Peshawar that led to mass protests and vandalism, further eroding the public trust; and
• The launch of typhoid conjugate vaccine (TCV) among children aged 9 months to 15 years in the provinces of Sindh and Punjab (during 2019 and 2021, respectively), which led to injection anxiety causing nausea and vomiting among a few children - with video going viral on social media.

In a health emergency, such as a pandemic, governments rely on public trust in their policy and anticipate its compliance to protect health and save lives. Vaccine hesitancy compromises this process when an emergency involves infections. Formative studies about the COVID-19 vaccine indicated that two-thirds of Pakistanis were willing to receive the vaccine. Studies with health workers from Pakistan suggested that being transparent about vaccine delivery and providing complete and actionable information about logistics would be key.

Through a seminal step, Pakistan's Ministry of National Health Services, Regulations and Coordination ensured the presence of the communication team at the decision table of the National Command and Operations Centre, the place where vaccine strategy evolved. The communication team had its fingers on the community's pulse through information coming from lady health workers (LHWs), a call-in helpline, successive surveys, and social listening arrangements. This situation allowed a feedback loop of knowing community expectations, addressing them through policy decisions, and then letting the community know of these decisions and the system's expectations about community behaviours.

The resulting communication strategy (see figure above) comprised a central theme of building confidence in the vaccine delivery, with 4 complementary pillars, including:

1. Messaging to facilitate behaviour (vaccine uptake): This pillar comprised 3 streams: (i) messages on mass and social media that communicated the vaccine's importance, safety, and effectiveness, with mobile phone text messages that conveyed information about when, where, and how to get the vaccine; (ii) a platform (1166 helpline) where people could call free of cost for answers to their questions; and (iii) education about how to manage information overload and decipher right information from wrong, including religious scholars emphasising in media and Friday sermons that the vaccine is halal [permissible].
2. Adverse events following immunisation (AEFI) management: A communication protocol was prepared for healthcare providers (HCPs) to inform vaccinees about the vaccine and its potential AEFIs before the vaccination.
3. Crisis communication: The 3 elements included: (i) preempting crises by explaining side effects prior to vaccination and monitoring for 15 minutes afterwards; (ii) addressing crisis if it emerges, using the "AEFI" language; and (iii) neutralising a crisis by pre-bunking (providing information that puts misinformation in context when it strikes) and debunking (addressing falsehood) misinformation via the 1166 helpline, mainstream media, and social media.
4. Field and online monitoring: Data from 3 different sources were used to develop a triangulated picture to inform communication decisions: the overall vaccination trends; community narratives and questions emerging from social listening, community surveys, and 1166 helpline calls; and AEFI monitoring data.

Aligned with Bronfenbrenner's socioecological model, the strategy was sensitive to an individual's decision process, which will be influenced by factors like discussions with family and friends, religious beliefs, advice from HCPs, information on social media from sources all over the world, and past memories of polio incidents.

The paper offers a short description of each element of this strategy. However, in brief, different ecological layers and their interplay were addressed to enhance vaccine acceptance. At the micro-level and meso-level, information about vaccine safety and effectiveness was provided, along with addressing pro-sociality. Health workers and religious scholars were involved in generating a positive influence from the exosystem. Addressing misinformation about the vaccine and getting endorsements about the programme from global influencers (like the World Health Organization) comprised the macrosystem, while preempting the possible repercussions from past events (e.g., polio debacles) attended the chronosystem.

Examples of specific elements that comprised the centrepiece of the strategy include:

• Publicising the vaccine authorisation by the national authority: The Drug Regulatory Authority of Pakistan (DRAP) reviewed the data for each vaccine to ensure that evidentiary requirements for safety and efficacy are fulfilled before its approval. The formative discussions with HCPs indicated that authorisation of the COVID-19 vaccine by DRAP is critical for its safety and acceptance. To satisfy this need, the authorisation of each vaccine was widely publicised.
• Informing the public about adequacy of doses: At the beginning of the campaign, the doses were in short supply. Pakistan availed all opportunities for procuring the vaccine and consistently informed people about the arrival of the doses. Announcing the availability was important for those who, in the interest of others, were delaying their vaccination until the more deserving got it.
• Maintaining an ultra-cold chain: Given Pakistan's warm weather, concern about vaccine storage was prevalent among HCPs and the wider population. The programme ensured that ultra-cold storage is not only maintained but also made visible by publicising this fact in the media.
• Providing public information about phased administration: Due to supply issues, the government started by inoculating the HCPs, followed by the elderly. This sequencing resulted in 12 phases, each advertised on media. The potential recipients during that phase also received a specific text message with unique code and details including the date, time, and location where they would receive the vaccine.
• Integrating COVID-19 vaccination with routine immunisation: The rollout of the COVID-19 vaccine rested with the Expanded Programme on Immunisation (EPI), a programme previously responsible for immunising children. In rural areas, the delivery points were the same as those for children, making integration visible. The outreach for other campaigns (e.g., TCV) also promoted the COVID-19 vaccine by advising the people to get protected. The optimal COVID-19 vaccination was coordinated through all modes - that is, static, outreach, and mobile vaccine delivery

Pakistan's national vaccination data show that, due to challenges in procuring the vaccine early on, the country could administer only 2.5 million doses in the first 3 months of the campaign. Once it managed the procurement, the country went on to vaccinate 58% of its population by administering an additional 240 million doses in the next 12 months, an increase much higher than any other country in South Asia having a similar context.

People's perceptions about the COVID-19 vaccine also improved over time. The most common reason for indecision was waiting for safety information, which decreased by 20 percentage points during from May 2021 to May 2022. Similarly, all other reasons for hesitancy decreased over that year, except for being unsure about vaccine efficacy and religious reasons, which increased by 2 and 6 percentage points, respectively. This small rise in the last two can be explained by breakthrough infections and occasional, politically motivated anti-vax statements of some religious leaders, despite continued engagement with them.

Reflecting on the findings, the researchers suggest that the following elements be added to global guidance:

• A confidence-building centrepiece aimed at keeping people informed about the policy decisions, which policymakers usually that community members may not need or understand; and
• A mechanism to monitor and respond to people's reactions to an evolving vaccine delivery apparatus whereby those willing to vaccinate are reciprocated with a competent and welcoming vaccine delivery system, and those showing hesitancy are repeatedly reached to address their concerns and help them switch to the willing category.

In conclusion: "The acceptance or rejection of life-saving interventions like vaccines is not just intrinsic to people, the adoption also depends on how the system appears and reaches out to them. For this, system should not only perform, but its performance should be manifestly visible to build public trust. Approaching the hesitancy on a sliding scale that can be addressed through influencers embedded in the socioecological layers is a helpful tool in building this trust. Health workers, especially those at the front line, are most critical in this social ecology and their communication can make or break a vaccination programme."