American Association for Cancer Research Annual Meeting

American Association for Cancer Research Annual Meeting


Ribas A, et al. Building vaccine confidence: Best practices to combat misinformation and vaccine hesitancy in COVID-19 vaccines. Presented at: American Association for Cancer Research Annual Meeting (virtual meeting); April 10-15, 2021.

Disclosures: Collins, Greenberger and Hamel report no relevant disclosures.
April 26, 2021
5 min read

American Association for Cancer Research forum addresses COVID-19 vaccine hesitancy


Ribas A, et al. Building vaccine confidence: Best practices to combat misinformation and vaccine hesitancy in COVID-19 vaccines. Presented at: American Association for Cancer Research Annual Meeting (virtual meeting); April 10-15, 2021.

Disclosures: Collins, Greenberger and Hamel report no relevant disclosures.
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The medical research community’s swift response to the COVID-19 pandemic has led to the development of multiple vaccines within less than a year and the full vaccination of 94 million Americans against the novel coronavirus.

The rapid rollout has raised concerns among the public — including some individuals with cancer — about the overall safety of the vaccines.

NIH Director Francis S. Collins, MD, PhD

“What I’m hearing from my local patient community is that there are waves of emotions —excitement about the science of developing vaccines, and fear of what they’re going to do,” Liz Hamel, vice president and director of public opinion and survey research at Henry J. Kaiser Family Foundation, said of her informal interactions with people who have cancer. “There’s uncertainty and anxiety, because people living with cancer were not necessarily included in the initial trials and studies. There’s also a longing to return to some form of life, because these patients may be in an advanced cancer setting and they want to go and live whatever life they have to the best of their capabilities.”

Hamel discussed public perception of COVID-19 vaccines with other panelists during a forum at American Association for Cancer Research Annual Meeting titled, “Building vaccine confidence: Best practices to combat misinformation and vaccine hesitancy in COVID-19 vaccines.”

Reducing development ‘downtime'

The development and approval of the COVID-19 vaccines within months, compared with decades for previous vaccines, is “pretty astounding,” NIH Director Francis S. Collins, MD, PhD, said during the forum.

“In this instance, in just 11 months from the initial identification of the SARS-CoV-2 pathogen in January of 2020, we had not one, but two vaccines: the mRNA vaccines from Pfizer and Moderna. I think people have been concerned that this speed, while it’s ultimately a good thing, might indicate that corners were being cut that could affect safety and efficacy.”

However, Collins said research into the vaccines was thorough and robust.

“I want to assure you, as a guy who has been deeply engaged in vaccine development, that I have never seen an effort to develop a vaccine conducted with this kind of vigor,” he said. “What made it possible to do this more quickly was careful planning beginning on the day that the sequence of that viral genome was released.”

Collins said under normal circumstances, there is often “downtime” during the development process.

“Then if it actually works, it takes months to build a factory to produce enough doses,” he said. “That was simply unacceptable in this circumstance, which is the worst pandemic in 103 years. Basically, the way we sped up the effort was not to compromise all the scientific steps or the rigorous trials; it was to get rid of the bureaucratic pauses in between those phases.”

Collins noted that every vaccine considered for FDA approval undergoes a phase 3 randomized, controlled trial with at least 30,000 participants.

“Then a data and safety monitoring board looks at the data and decides whether, in fact, it is ready for a decision about efficacy,” Collins said. “None of the trials can be presented to the FDA for consideration until at least half of the participants have been followed for at least 2 months after their first dose, in order to look for safety signals.”

Targeting ‘moveable middle’

The Kaiser Family Foundation launched its COVID-19 Vaccine Monitor in December to track public perceptions of and experiences with COVID-19 vaccination. Results of the monitor, based on survey responses and qualitative data, showed that overall vaccine confidence has increased over time in the United States, Hamel said.

“In December, just a third of the public said that they were ready to get the vaccine as soon as it was available to them and, in our latest measure, in March, that’s up to six in 10 who have already been vaccinated or want to be as soon as possible,” Hamel said. “Also, the [percentage of] people who want to wait and see how the vaccine is working for others first — sometimes this is called the ‘movable middle’ — has decreased over time, from 39% to 17%. We see this wait-and-see group as a crucial target for increasing confidence and potentially converting them to the ‘as-soon-as-possible’ category.”

Hesitancy in cancer population

Individuals with hematologic malignancies often are immunocompromised and may be at risk for more severe COVID-19 illness and death than the general population. Yet, these patients also may be more reluctant to get vaccinated, according to results of a survey by The Leukemia & Lymphoma Society.

Lee Greenberger, PhD
Lee Greenberger

“People need to realize that the registration trials for the vaccines largely excluded [patients with cancer],” Lee Greenberger, PhD, the society’s chief scientific officer, said during the forum. “I know for [patients with blood cancer], this was going to be a particular issue, because [these] patients tend to be immunosuppressed and may not respond to vaccines. We saw the variants start appearing in Russia, Germany, the U.K., Boston, New York, Pittsburgh and Seattle in [patients with blood cancer], or patients treated with the same therapies that are used to treat blood cancer.”

The survey, conducted in December, asked more than 100,000 people in the society’s registry of patients with blood cancer whether they planned to receive the vaccine.

“The good news is that about 70% were likely of very likely to get vaccinated,” Greenberger said. “The concerning news was that one in five were unlikely or very unlikely to get vaccinated.”

Concerns among this population mirrored those of participants in the Kaiser Family Foundation survey, according to Greenberger.

“They felt the safety wasn’t established,” he said. “They didn’t trust the studies to date. It’s important to recognize that people who are vaccine-hesitant also tend to be less likely to engage in protective health behaviors, such as wearing masks.”

The study also revealed financial concerns among patients with blood cancers.

“These concerns were about dealing with the blood cancers themselves and dealing with getting vaccinated and taking time off from work,” he said. “So, the problem is not simply getting to a vaccine; it’s a much more comprehensive problem in [patients with blood cancer].”

Greenberger said the society intends to repeat this survey to determine whether attitudes change over time. He encouraged patients with blood cancers and their families to get vaccinated against COVID-19 as soon as possible.

“There’s no question that herd immunity is what we’re after and, in the case of a [patient with blood cancer] who may not respond to the vaccines, getting everyone around you vaccinated, especially your household members, makes a lot of sense to us,” he said. “It’s an easy thing that should happen.”

Effective messaging

Public information campaigns are one way to help the public learn more about COVID-19 vaccination and dispel misinformation that may be circulating, according to Collins.

“There is a lot of misinformation out there, particularly in social media, which is portraying vaccines in ways that scare some people,” he said. “We now have something called the COVID-19 Community Corps. Our goal is to make sure as much accurate information is out there as possible.”

Hamel said Kaiser Family Foundation’s ongoing surveys have identified messages that may inspire vaccine confidence.

“Messages that emphasize the effectiveness of the vaccines, particularly when it comes to severe disease and death, really resonate with the largest share of people in the wait-and-see group,” she said. “In terms of the speed at which vaccines were developed, we’ve found that telling people that although these vaccines themselves are new, scientists have been working on this technology for 20 years [may reduce hesitancy]. It’s also helpful to mention that over 100,000 people from diverse backgrounds were included in the clinical trials, or that most doctors who have been offered the vaccine have taken it.”

Inspiring vaccine confidence will require more than public information campaigns, according to Hamel.

“It’s not just about messaging; it’s also about making sure we have policies that address vaccine access,” she said. “We’ve found that for many people, particularly people of color, taking time off work for the vaccine or dealing with serious side effects of the vaccine are a concern. They are worried about being able to travel to places they can trust.”

Giving workers paid time off or ensuring that vaccines are available at trusted locations in their communities could instill confidence in the vaccines, Hamel said.

“These are concerns that won’t necessarily be addressed with messages,” she said, “but could be addressed with policies.”