Johns Hopkins Outlines Public Health Challenges of Achieving Mass COVID-19 Vaccination
With billions of doses of COVID-19 vaccines expected to be available by year’s end, and a global population of 7.8 billion, public health officials are scrambling to deliver the vaccines in ways that are equitable and effective. The challenge is about more than having a vaccine, and more than delivering it, public health experts at Johns Hopkins Medical School explained during in a media briefing Wednesday.
Vaccination has two major roles. One is to prevent individuals from becoming infected or, if they do become infected, to reduce the severity of their symptoms. The other is to enable herd immunity, which occurs when a sufficient number of people develop antibodies to the virus that the risk to unvaccinated individuals is significantly reduced.
With COVID-19 vaccine trials being accelerated and drug manufacturers predicting vaccine availability this fall, some are concerned that such speed comes at the risk of not determining side effects. The determining factor, though, according to Naor Bar-Zeev, Ph.D., deputy director of the international Vaccine Access Center at Johns Hopkins Bloomberg School of Public Health, is not the timeline but the number of doses delivered. Very large trials are being initiated so, he said, “Common side effects will be identified, but not, perhaps the rare side effects. Therefore, the public should prepare for unexpected results and even for the withdrawal of a vaccine” as real world evidence accumulates.
The public needs to understand, too, that the manufacture of billions of doses doesn’t mean that they can be vaccinated soon.
“There are 7 to 8 billion people on Earth, and the vaccines will be distributed with a certain percentage to each country, which will prioritize distribution within their borders,” Bar-Zeev said. That typically means healthcare workers and older adults. The questions now, he said, are whether to prioritize essential workers, what constitutes “essential” workers, and whether their families also should receive priority vaccination. “Vaccination for all is a far-away goal, if we get there at all.”
Although a vaccine is a powerful deterrent to the epidemic, “Even if a vaccine is 100% effective, if only half of Americans are vaccinated, we won’t build herd immunity,” Bar-Zeev said. Building herd immunity is more important even than having a perfect vaccine. “The purpose of social distancing is to free up beds, so even a less-than-100% effective vaccine is still a success.”
Under-performance is less of a risk, therefore, than a short duration of benefit. As Dr. Bar-Zeev pointed out, “If it’s 100% effective but only for six months, it’s not feasible to keep vaccinating.” He said, however, that innovative means of delivery – such as a vaccine patch – while not available now, may ease that hurdle in the future.
“Immunization in the context of social distancing also is an issue,” Monica Schoch-Spana, PhD., senior scholar, Johns Hopkins Center for Health Security, said.
Colleagues around the world have reported that their governments’ social distancing mandates have made it difficult to receive medical care. For example, “Women have been turned around on their way to the hospital for childbirth,” he added.
Mistrust of vaccinations is a growing concern and a significant public health issue. A recent article in Science noted that half of all Americans expect to refuse vaccination for COVID-19.
“This is a historic moment in the U.S., with pronounced social fractures. We are seeing hesitancy to be vaccinated forming around political and racial lines,” Schoch-Spana told BioSpace. In this fractious environment, “we’re seeing individuals who normally would be vaccinated have misgivings about a vaccine developed during the current Administration, and others who are motivated to be vaccinated because of encouragement from the current Administration.”
As Bar-Zeev told BioSpace, “We’re in novel territory with a new disease. Scientists are learning very, very quickly, but the vaccine and platforms are new and uncertain. We’re seeing science live, in real time, but that leaves people feeling uncomfortable.” The general public, he said, thinks of science as immutable. “The more open we are, sharing with them, the better things will be in the long term.”
For example, Bar-Zeev advised alerting adults to side effects – typically chills, fever and body aches – up front so people can make an informed decision regarding COVID-19 vaccination. Serious side effects likely will be rare, and some people may experience none, or only mild side effects. Reactions may occur in the first dose but not the second, or vice versa. Knowing this – particularly for two-dose vaccines – will affect vaccination rates will help determine whether people opt for a second inoculation.
To encourage vaccinations, Schoch-Spana advocated an in-depth social outreach plan focused on the social – not scientific – benefits of vaccination. For example, reducing the severity of COVID-19 means reducing the number and duration of hospital stays, and resultant medical bills.
“It means getting back to work and returning to worshipping in a familiar way sooner. Communication is critical as an antidote to misinformation,” Schoch-Spana said.
She called for the Centers for Disease Control & Prevention to discuss the benefits of vaccination at a national level, and then for independent, politically-neutral, local bodies to hyper-localize vaccination information to address local concerns.
Then, vaccinations need to occur in convenient places, in addition to the usual vaccination sites like pharmacies and doctors’ offices. One example, she said, is the performance of “diagnostic testing in Black churches. We need a local assessment of inadequacies and locations, involving minorities and other marginalized groups.”
These and other social and technical issues of equitable vaccine allocation are being addressed by the CDC’s Advisory Committee on Immunization Practices and by a new committee formed by the National Academies of Sciences, Engineering, and Medicine and the National Academy of Medicine (NAM).