Principal Investigator, Research Scientist
Several countries are administering the first COVID-19 vaccines. One of the biggest questions now is how many people will be willing to take these vaccines once enough doses are available for the general public. Julia W. Wu, an epidemiologist and principle investigator in the Human Immunomics Initiative of the Human Vaccines Project and the Harvard T.H. Chan School of Public Health, is collaborating with social scientists to understand vaccine acceptance and to develop tools to increase public confidence in vaccines. HVP Editor Kristen Jill Abboud spoke with Wu about her work, which is now being prepared for publication.
An edited version of the conversation appears below.
Is vaccine hesitancy a bigger issue today than it was in the past? And how does it vary geographically?
Vaccine hesitancy was always there—it is not new at all. It started from the very beginning because these are products that are administered to healthy people. Vaccine hesitancy was largely dependent on the social, cognitive, economic, and historical context of how people viewed vaccines and their perception of infectious diseases. There wasn’t widespread acceptance of vaccines until recent decades, but then there were some factors that contributed to vaccine hesitancy. Even a decade after the retraction of a faulty paper that erroneously linked autism with the MMR [measles, mumps, rubella] vaccine, this misconception still exists. The internet and social media changed the way people consumed this type of information and gave rise to the anti-vaccine communities that exist today, largely in rich countries. In some other countries, there is mistrust of vaccines because of religious, political, and historical factors. There are a lot of different pieces that go into these beliefs and perceptions. Vaccine hesitancy is not a singular phenomenon. My historian colleague, Emily Harrison, and I wrote a paper on this earlier this year.
Is this different for COVID-19 vaccines?
We are conducting a global COVID-19 vaccine acceptance survey study among pregnant women and mothers of school-aged children, and so far three key factors really stand out: the perception of the risk of the disease, the general public trust, and the general pre-COVID-19 vaccine attitude. With COVID-19, we are dealing with a new disease with a lot of uncertainty. We also have innovation and vaccine discovery happening at an unprecedented speed. That is a lot for people to process, especially with the misinformation that exists. All of these factors have contributed to people’s hesitancy.
But even though COVID-19-specific vaccine hesitancy is a new phenomenon we are studying, what we are learning is that this follows what we have known in the past regarding the general factors that affect acceptance of vaccines. Public trust is key in terms of people’s willingness to get vaccinated. Vaccine acceptance really depends on a community decision and it requires people to not only consider their own risk, but also the risk for the community. If the social solidarity is not there, it is much harder to convince people.
Acceptance of vaccines is also dependent on how the government handled or mishandled this pandemic, and more broadly, the culture of public health in a country. It goes beyond just combatting COVID-19. It has a lot to do with the approach to public health, as we’ve seen with mask wearing and other compliance issues. It is not surprising that people who are not complying with public health measures are less willing to accept a vaccine.
We are also finding that many of the countries in the global south are very familiar with infectious diseases, so they appreciate the benefits of vaccination. In the U.S. and Europe, we’ve become much less familiar with the horrors of infectious diseases, until recently.
Do you suspect that the willingness to be vaccinated will improve given the first COVID vaccines are so effective?
Absolutely, and we see that in the preliminary survey data. In several surveys people have been asked about this, and, with higher efficacy, people are more accepting of vaccines. I think there is simply a risk/benefit ratio and when people are weighing those benefits, an extremely high efficacy gives people more confidence in the vaccine and it makes the benefit more concrete.
How do you try to influence vaccine acceptance? What are the most effective approaches to changing people’s minds?
From the surveys that we have seen, there are a few aspects. One is increasing people’s trust in a vaccine. That can happen through transparency from a top-down point of view. Then there is also a lot of community building that can be done at the grassroots level. Community work is extremely important when we are trying to roll out vaccines. We have also learned from the Ebola vaccine trials that peer influence is a huge factor. The goal is to engage community members but not impose upon them. Different groups of people have different concerns, and so it is important that we address these concerns through peer learning.
Another important factor is to not just focus on the vaccine. What we are experiencing is a huge crisis, and everything needs to be put in perspective. We need to focus on the risk of the virus, not just the risk of the vaccine. Clearly, the benefit of the vaccine outweighs the risk tremendously. Yet some survey responders asked why we need a vaccine for a disease that has a 99% survival rate. That shows their perceived risk of the virus. If you perceive the risk from this virus purely based on the survival rate, then we are ignoring the tremendous sacrifices we are making as a society to maintain that survival rate—the huge economic slowdown, the social and psychological suffering, etc. Here, we have a lot to learn from developing countries.
The essence of these surveys is to really hear from the people on the ground—to hear the concerns, fears, and motivations of different sub-groups. We need to truly understand them in order to help, and this has to be broader than just COVID-19, which eventually will subside.
Interview by Kristen Jill Abboud