Without a vaccine, it will take far longer for humans to reach collective immunity against the SARS-CoV-2 virus. According to early estimates from US health experts, at least 70% of the population may need to develop immunity to the SARS-CoV-2 virus, either by exposure to it or through vaccination, to achieve herd protection.
“We’re not going to get this virus under control until either we get a vaccine or it infects 80% or 90% of the population, and the latter is an outcome we don’t want because a lot more people will die,” infectious disease researcher Sarah George, MD, who is the principal investigator of a leading clinical trial for remdesivir at Saint Louis University, St. Louis, MO, told Popular Science.
A safe and effective vaccine for COVID-19 is “doable” by January 2021, said Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases. Meanwhile, scientists at Oxford University, London, UK, said that their coronavirus vaccine could be ready as early as September of this year.
Importantly, if and when a COVID-19 vaccine becomes available, it will be able to produce herd immunity only if an overwhelming majority of Americans get vaccinated.
Not following the herd
More than 90 potential COVID-19 vaccines are being investigated worldwide, so it seems likely that at least one will be successful. And, when that happens, we’ll all gladly line up to get our COVID-19 shot, right? We’ll do anything to get past this awful crisis, won’t we?
Maybe not. Maybe some people won’t get in line. So, what would happen if a safe and effective COVID-19 vaccine becomes available, yet some people simply refuse to get it?
Consider what happened as recently as 2019 when a measles outbreak occurred in Brooklyn, NY. Nearly 3 in 4 cases (73%) occurred in people (predominantly children) who had never received the measles vaccine.
Although this isn’t an apples-to-apples comparison with the current COVID-19 pandemic (for instance, we don’t even know yet whether SARS-CoV-2 antibodies can thwart reinfection), it provides a glimpse of the magnitude of the problem if a large minority of Americans aren’t immunized.
What would daily life be like if, say, one-fourth of the population refused to be vaccinated? At the very least, the virus could remain an ever-present problem for years. Social distancing and wearing masks in public could become the new norm. Students may continue to attend schools and universities only online. Cities and counties may try to reopen, but if infections and deaths resurge—much like we’re currently seeing in South Korea and China—new lockdowns would ensue. Treatments like remdesivir may be approved, but outbreaks could still occur each year, and the worldwide number of deaths from COVID-19 would continue to accrue.
Skeptics and believers
This is not a theoretical scenario. According to the authors of one preliminary study, about one-quarter of adult Americans (23%) said they’ll refuse to get a COVID-19 vaccination when one becomes available.
For this study, which is currently undergoing peer review, investigators recently surveyed a demographically representative sample population of 493 US adults. They asked the participants about their views of vaccine safety and whether they plan to receive a vaccine against COVID-19.
Nearly one-fifth (19%) of respondents characterized themselves as being skeptical of vaccines. Of these, 62% said that they would not get the COVID-19 vaccine.
About one-sixth (16%) of all respondents specifically self-identified as anti-vaxxers. Among these, 44% said they won’t get vaccinated against COVID-19.
Although most people said they do plan to get the vaccine (when available), the number of those who said they won’t get it may be high enough to threaten the nation’s collective immunity, the authors concluded.
“We believe that these findings, although preliminary, suggest that many people who hold anti-vaccine beliefs may jeopardize the effectiveness of a COVID-19 vaccine once it’s available, due to issues of noncompliance,” wrote Kristin Lunz Trujillo, a PhD candidate in political science, University of Minnesota, Minneapolis, MN, and Matt Motta, PhD, assistant professor of political science, Oklahoma State University, Stillwater, OK, in an article in The Conversation.
You miss the shots you don’t take
Sadly enough, these results didn’t really surprise the investigators.
“This is pretty much what we expected to find,” Dr. Motta told MDLinx. “The amount of vaccine skepticism we observe throughout the COVID-19 pandemic looks a lot like the amount of skepticism we observed before the crisis. Since skeptics are less likely to want to vaccinate, it's not too surprising to see that a majority of skeptics might refuse a COVID-19 vaccine, when it eventually comes out.”
In other words, people are prone to continue to believe what they’ve long believed already. And such biases increase when faced with anxiety-inducing societal events, such as public health threats. As the situation worsens, these biases can become more entrenched.
“For most people, this means that they will seek out information on COVID-19 and put more trust in medical experts,” said Lunz Trujillo to MDLinx. “But if someone is already biased against vaccines, the medical establishment, etc, then they will keep these biases, and be skeptical of medical expertise or other established experts.”
Although the investigators expected such a response, what surprised them was the number of people who said they would reject COVID-19 vaccination even though they aren’t vaccine skeptics.
Specifically, 15% of people who are at least somewhat supportive of vaccines said that they wouldn’t get the COVID-19 vaccine. Moreover, 19% of people who did not identify as anti-vaxxers said they wouldn’t get vaccinated.
“Are they simply waiting to see what form the vaccine takes, and what the clinical trials might produce?” Dr. Motta said. “Is there something not directly related to concerns about vaccine safety that might be driving hesitation (eg, concerns about the costs—either physical or monetary—of being able to receive the vaccine from a doctor or pharmacy)? Figuring out the answer to these questions could prove pivotal in designing campaigns aimed at increasing vaccine uptake.”
It seems difficult to believe that anyone would need to be convinced to take a small simple action, like getting a vaccine, if it means stopping the COVID-19 threat. Nevertheless, such campaigns may face an uphill battle with some skeptics.
“Prominent anti-vaccine websites have already begun circulating misinformation about the COVID-19 vaccine—such as the idea that a vaccine has existed for years and has been kept from public consumption,” the investigators wrote in their article. “Additionally, recent research suggests that anti-vaccine views are tied to deeply held psychological and moral aversions to inoculation, implying that attitudes may be difficult to change.”
Then again, there are no atheists in foxholes. That is, the current dire circumstances may indeed encourage vaccine skeptics to change their minds. Researchers have found that when nearly-eradicated diseases come back as epidemics, people may be more likely to trust recommendations from public health experts, noted Lunz Trujillo and Dr. Motta.
There is a lot that remains uncertain about the future of this virus and its impact on the nation (and the world). It’s unfortunate that one of the big uncertainties may occur due to opposition to a potentially life-saving vaccine.