Kathryn Stephenson, MD, MPH (Center for Virology and Vaccine Research, BIDMC) shared how the impact of low vaccination levels can be significant for long-term public health for two reasons: first, pockets of ongoing infection in one community can be a source for new outbreaks in all communities in the future; second, it can significantly exacerbate already stark health disparities between communities.

The Independent (UK) – December 21, 2020

The impact of the anti-vaxx movement: What happens if only half the country gets the Covid vaccine?

About 53 per cent of Americans say they will take a first-generation Covid-19 vaccine, poll finds

The first coronavirus vaccine received emergency use authorisation from the Food and Drug Administration (FDA) this month, but how effective the treatment is against halting the pandemic will hinge on public confidence in the jab. 

Dr Anthony Fauci, the nation’s leading expert, has estimated about 75 to 80 per cent would be an optimal number of people to receive a vaccine in the coming months to return to some semblance of “normal”. 

Unfortunately, an Axios-Ipsos poll released found that just 53 per cent of the public would likely choose to receive the vaccine.

If public approval does not increase, experts warn of high mortality rates as the virus continues to surge through vulnerable populations of the unvaccinated – extending the pandemic and the need for Americans to continue to practice coronavirus precaution guidelines, such as wearing a mask and social distancing, for longer until herd immunity is reached – if it can be reached. 

“The impact [of low vaccination levels] can be significant for long-term public health for two reasons,” Dr Kathryn Stephenson, director of the Clinical Trials Unit for the Centre for Virology and Vaccine Research at Harvard University’s Beth Israel Deaconess Medical Centre, told The Independent

“First, pockets of ongoing infection in one community can be a source for new outbreaks in all communities in the future, if or when vaccine immunity wanes. But second, and more importantly, it can significantly exacerbate already stark health disparities between communities,” she said. 

Health officials will need to rely on equitably distributing the vaccine geographically across the US, as well as within different “social groups” of the population, in order to halt new infections from creating hospitalisation and death rate surges among vulnerable communities.

All of which would rely on increased public approval of the vaccine. 

What communities are most at risk if vaccine approval doesn’t increase?

Dr Stephenson said experts anticipate about 60 per cent of Americans within a specific “social circle” would need to be vaccinated to “reverse the pace of new infections, such that we can end this pandemic completely.” This number would only work if the vaccines proved to prevent infection transmission to others. 

“How we define a social circle really matters,” Dr Stephenson said. “If there are pockets of groups that are separated from each other socially, then low uptake in one of those groups will mean that outbreaks continue in that group.” 

Geography, religion, economics, and race are all reasons why groups of people could be separated, Dr Stephenson added, which impacts how well the vaccine works depending on how it is distributed. 

Disproportionately communities of colour have been hit harder by the coronavirus pandemic due to the growing social, economic, and health disparities that were further exacerbated by the novel virus. 

Lack of healthcare, testing, and treatments has been found in these communities across the US. So even with the introduction of a coronavirus vaccine, it remains a challenge for public health officials to provide access as well as acceptance of this vaccine to these communities. 

“We have a lot of work to do to ensure equitable distribution of the vaccines and outreach to communities that may have higher levels of distrust about the vaccine,” Dr Lisa Maragakis, the senior director of infection prevention for John Hopkins Health System, told The Independent

“I am speaking about including populations that are at the highest risk for severe consequences of the infection, so minority communities, vulnerable populations, people who are experiencing homelessness,” she added. 

Black communities have a distrust towards the American healthcare system due to past treatment and the belief providers will not act in their best interest. Historically the healthcare system used Black Americans’ bodies without their consent on medical treatments and advancements, leading to the current distrust. 

Although 71 per cent of Black Americans know someone who has been hospitalised or died from Covid-19, only about 42 per cent said they would currently receive the vaccine, according to a recent survey by Pew Research Centre

Comparatively, more than 60 per cent of Hispanic and white adults said they would receive the vaccine, according to the survey. 

So a lack of approval of the vaccine could further exacerbate the number of Black people who are disproportionately hospitalised and dying from Covid-19. 

“Those individuals who are unvaccinated and vulnerable may continue to contract the virus and potentially have very severe consequences,” Dr Maragakis said. “So really the ideal is getting to a place where we have broad levels or protection and a very high level of immunity everywhere so that we can all breathe a sigh of relief.”

In her opinion, it would be optimal for at least 70 per cent of the population to have a combination of “natural immunity from having the infection before” and immunity through a vaccine. There are more than 330 million Americans, which will make distributing the coronavirus vaccine the largest distribution campaign the country has ever done.

Why is natural herd immunity not an option?

Throughout the coronavirus pandemic there has been the suggestion that creating natural herd immunity among the public by getting lower-risk populations to become infected with the virus could be one way to respond.

But Dr Maragakis warned against the public taking the perspective that herd immunity through natural infection would protect them alone.

“Because this infection has such a high mortality rate compared with other infections like the flu, absolutely we do not want to reach herd immunity through natural infection because so many people would die unnecessarily,” she said.

The vaccine will instead accelerate herd immunity, helping the public reach “the level of immunity that will protect the vast majority of the population,” she said.

Similar to vaccinated individuals, those who previously were infected with the novel virus were still advised to wear masks and practice social distancing to avoid spreading Covid-19 to others. It was also recommended for individuals to still receive the vaccine even if they already had Covid-19.

“We know we can’t get to a 100 per cent immunity in the population but if we can get it high enough then we interrupt that viral transmission and protect the most vulnerable among us who don’t have immunity themselves,” Dr Maragakis said.

How does a broad vaccination campaign matter geographically?

There is an emphasis on vaccinating the broad public in the country and around the world because of how the virus has travelled between communities. 

High vaccination rates in the coastal states, for example, would not control the spread of Covid-19 as swiftly if those same rates were not experienced in the midwest, given how Americans travel throughout the year.

But the divide between smaller “social groups” in states who largely only interact with each other could also impact the broad public vaccination campaign. Public health officials will need to locate where these social groups are and provide them with both information and access for the vaccine. This would be imperative in order to avoid specific communities from suffering long-term infection and death rates. 

“We often think that populations mix more than they do,” Dr Stephenson said. “Maps in Boston, for example, show persistent stark segregation between Black and white communities based on what block they live on.”

“If Black communities have low uptake [in the vaccine] compared to white communities, then the disproportionate death rates will continue to separate tremendously – from three times the white death rate, to much higher than that,” she said. 

This means the outbreak would also likely “persist in these communities over a much longer duration” compared to those who embrace the vaccine. 

“Meanwhile, you can imagine white communities going into the ‘green’ zone, with schools opening and everything else,” Dr Stephenson added. “The long-term impact on disparities will be incalculable.” 

Globally, a broad vaccination scale would also be heeded because of how travel could continue to help spread the virus to communities all around the world.

“It really is in our best interest to care that there be sufficient vaccine supplies worldwide and equitable distribution worldwide so that everyone is protected,” Dr Maragakis said.

Is there concern of Covid-19 mutating? 

Following the Pfizer beginning its coronavirus vaccine distribution in the US, news broke of a potential new strain of the novel virus appearing in the United Kingdom – sparking concern about mutations and its impact on the jab.

The issues started when the UK’s Health Secretary Matt Hancock announced last week that more than 1,000 confirmed coronavirus cases in southeast England showed genetic mutations that were potentially driving the surge.

Thus far, though, there have been no reports of a higher mortality rate among different strains of Covid-19 or enough difference to impact the efficacy of the vaccines. But scientists were watching out for mutations in case it could impact treatments.

“Concern about mutation is one reason to want to go as quickly as possible to achieve high levels of vaccination,” she said, adding: “But I think more importantly we know the virus is everywhere right now, and it is surging, at least in the Northern Hemisphere. So that, to me, is the real urgency to vaccinate as many people as we can as quickly as possible.”

Experts remain optimistic public approval will increase as more and more people are vaccinated in the coming months and other companies roll out their own coronavirus vaccines. Already public approval has risen from the 38 per cent recorded in October, according to the Axios-Ipsos poll, to the current estimate of 53 per cent.

“I am encouraged that over half of the population is accepting of the vaccine and trusting that this is the good news that we believe that it is in medicine and in public health,” Dr Maragakis said.

Now it would be up to public health officials to further build that trust by educating all communities in the US about vaccine efficacy, as well as making sure distribution is equitable to all at-risk population groups, she added.

“Science did guide the development of these vaccines and the scientific review and authorization, and so I would just urge everyone to seek out the information that they need from trusted, hopefully medical sources, and to get vaccinated.”