Increasing COVID-19 vaccine acceptance: Evidence from Mozambique

The COVID-19 pandemic has heavily impacted low- and middle-income countries (LMICs) with widespread food insecurity and falling living standards. To fully recover, countries will need not only an effective rollout of COVID-19 vaccinations, but also significant public trust and acceptance to ensure that they are taken up. In Mozambique, we conducted a study on how the information people receive about the vaccine affects their perceptions towards and willingness to get vaccinated, with recommendations provided to the Ministry of Health to scale what works.

Mozambique has struggled to cope with the pandemic’s effects while also recovering from the hidden debt crisis of 2016, the tropical cyclones of 2019, and the ongoing insurgency in the northern province of Cabo Delgado. In 2020, the country's economy registered its first contraction in 28 years, with 850,000 people estimated to have slipped into poverty (below $1.90 per day), as reported by the sixth edition of the Mozambique Economic Update. Consequently, Mozambique is expected to slow its progress towards meeting the Sustainable Development Goals (SDGs), setting back the gains made over the past years in health, education, and gender equality.

Securing vaccine doses for Mozambique

The beginning of a resilient recovery process in LMICs relies on rapid and widespread access to COVID-19 vaccines, crucial to achieve herd immunity and restore full mobility. Mozambique benefits from the global initiative COVAX, a multilateral venture to ensure equitable access to the vaccine in LMICs. COVAX seeks to ensure up to 20% vaccine coverage free of charge in its first phase, focusing on frontline workers and vulnerable populations. International partners are also expected to contribute to expand this coverage and strengthen the systems required to supply and deploy the vaccine. The first delivery of 384,000 doses of COVAX vaccines arrived in Mozambique on the 8 March, and countries like China and India have already donated hundreds of thousands more.

However, multiple challenges remain. The health system needs to be strengthened to effectively roll out the vaccines, which will rely on well-performing supply chains, prioritisation of vulnerable groups and those with co-morbidities, and extensive outreach of patients in remote areas. According to preliminary estimates, the costs associated with COVID-19 vaccination (including transport and deployment) in Mozambique could reach 260 million USD.

Ensuring citizens are willing to get vaccinated

Any strategy aimed at maximising access and uptake of COVID-19 vaccines globally must consider that the overall take-up rate will depend on personal choices. Given the sudden emergence of both the disease and the corresponding vaccines, it is paramount to ensure populations' acceptance by managing expectations correctly, reducing unjustified fears, and limiting the diffusion of misleading information.

In a recent study, we conducted a phone-based survey with participants of two previous studies, implemented in two distinct areas of Mozambique: the Greater Maputo Area and Cabo Delgado province. In thesurvey, we evaluate the impact of information provision on beliefs and attitudes towards COVID-19 vaccines. To provide valuable insights to the Ministry of Health and its partners, we developed and tested three information interventions to enhance vaccine acceptance, tested against a control group which received no infomation. The three interventions included:

1. Endorsement: Our benchmark intervention consisted of a simple message endorsing the COVID-19 vaccines. It blended individual and altruistic concerns and makes salient both the benefits of getting the vaccine and the risks of not getting it.
2. Memory: Our second intervention targeted the low level of trust in the capacity of the national health system by reminding respondents about the immunisation campaign that led to the successful eradication of wild polio in the country[1]. Recent literature shows how past medical campaigns and related narratives can have long-lasting effects on trust in the health system[2].
3. Pre-bunking: Our third and final intervention addressed concerns related to the widespread circulation of fake news. Corrective campaigns may not be enough to counteract misconceptions, and fact-checking interventions can backfire. We developed a pre-bunking intervention consisting of a persuasion inoculation exercise to raise awareness about the mechanisms behind the formation and diffusion of rumours. Its goal was to enhance the development of a critical view of unverified information. We framed this intervention around the evidence existing in the psychology literature on Inoculation Theory and its applications to health and risk messagingand COVID-19.

We implemented these interventions cumulatively, with Figure 1 summarising our main results. The combination of Endorsement, Memory, and Pre-bunking increased the respondents' stated willingness to take any COVID-19 vaccine when available. The substantial and significant increase in perceived efficacy and safety of the COVID-19 vaccines, together with a reduction in fear of negative side effects, seems to drive this result.

Figure 1. Impact of different messages on attitudes towards COVID-19 vaccines

Notes: The graph depicts average differences with the 'Control' group that did not receive any message under the study. All the outcomes refer to different individual questions/statements from the follow-up survey. 'Willingness to Take' refers to a 'Yes/No' question. The remaining outcomes refer to questions using a Likert scale from 1 to 5, with options ranging from 'Strongly Disagree' to 'Strongly Agree'. Answers were then transformed into dummy variables by recoding 'Strongly Agree' or 'Agree' as 1 and other responses as 0. (i) 'Endorsement' indicates the message endorsing COVID-19 vaccination. (ii) 'Social Memory' refers to the message eliciting memory of wild polio eradication in Mozambique. (iii) 'Pre-bunking' refers to the persuasion inoculation exercise to raise awareness about rumours' formation and spread. (iv)***, **, and * denote statistical significance at the 1, 5 and 10% level, respectively

Insights for Mozambique’s vaccine rollout

Messages reminding citizens about past successful immunisation campaigns can increase the willingness to take the new COVID-19 vaccines and their perceived efficacy. This result is valuable for policymakers since the Ministry of Health can quickly scale up this intervention, as suggested by its inclusion in their communication plan. Our findings also speak to the challenge posed by the widespread circulation of rumours and misleading information. In addition to increasing willingness to accept and perceived efficacy of the vaccine, exposure to a simple persuasion inoculation exercise effectively increases perceived safety and reduces fear of side effects.

[1] Noticeably, the Ministry of Health stated in its COVAX application: “The [communication] programme will refresh the memory of vaccination campaigns that have already taken place in Mozambique and have generally been very successful and have achieved high coverage rates throughout the country.” (Ministry of Health, 2020)

[2] Khan et al. (2020) recently found that providing information on past state effectiveness has limited effects on trust in institutions and perceived state capacity.