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As U.S. president-elect Donald Trump gets ready to be sworn into office later this week, his meetings with anti-vaccination activists have public health professionals deeply concerned.

Recently, Trump met with vaccination skeptic Robert F. Kennedy Jr., who has advocated for parents to more easily opt out of childhood vaccinations, to discuss naming him to a presidential panel on autism.

David Fisman, a public health professor at 91�Թ�'s Dalla Lana School of Public Health, says that with lower vaccination rates, outbreaks become more likely for highly infectious diseases like measles, mumps and rubella – which could lead to children dying.

91�Թ�’s Nicole Bodnar spoke with Fisman, an infectious disease epidemiologist, about the potential impact of vaccination skeptics assuming public policy positions.

Why is it dangerous to appoint someone with these views to a presidential panel?

Using a big platform like the White House to cast doubt on vaccines could lead to lower vaccination rates, which in turn raises the odds of a dangerous outbreak. 

When anti-vaccinationists are given credibility and they are able to influence policy, vaccination rates drop. When vaccination rates drop, diseases – especially highly infectious diseases like measles, mumps and rubella – resurge. When those diseases resurge, children are sickened and can die.

If it moves forward, this appointment is an extremely irresponsible move, but at the end of the day, Mr. Trump will bear the responsibility for outbreaks and epidemics that occur as a result of these signals because of his leadership position.

How can lower vaccination rates affect population health?

Society’s resistance to infectious diseases like measles depends on “herd immunity” – having a critical mass of people vaccinated against a disease. The lower the vaccination rates, the more likely an outbreak becomes. The less vaccination is supported, the less common it is likely to be.

When you decrease vaccine coverage for a disease like measles, which is a highly, highly infectious disease, there will be outbreaks and epidemics.

Is this trend aligned with what infectious disease scientists have seen in the past with vaccination behaviour?

Vaccination follows a predictable cycle. First, a disease afflicts and terrifies a society. Then, doctors develop a vaccine. The society, with fresh memories of the disease, embraces the vaccine.

For example, in the 1950s, people were so desperately frightened of polio that, notwithstanding the fact that they had real vaccine-related disasters, parents still lined up to get their kids vaccinated. They still wanted the vaccine, because they were much more frightened of polio than the vaccine.

The vaccine’s success leads to complacency: the disease is just held at bay, not defeated, but that effort isn’t visible. After a while, memory fades as to what the disease was. Then people just assume that that’s the way the world is – they don’t realize that that‘s a tangible output that requires ongoing effort to maintain, and that if you don’t have that ongoing investment, it goes away.

With fewer people willing to vaccinate, the disease returns – perhaps quickly.

This is a big challenge for public health. Our key outputs – immunity, clean air, clean water, healthy populations – are silent public goods that improve health for everyone in society. When things don’t happen, people might wonder: ‘Why are we funding public health? None of this stuff is happening!’ The fact remains that the non-occurrence of disease and death is the result of ongoing effort by public health professionals – it’s not just the normal state of affairs!

What do you predict if Robert F. Kennedy Jr. or like-minded people are given positions of power?

I predict a cycle in which increased opposition to vaccination causes vaccine coverage to fall. That then leads to fresh disease outbreaks. These outbreaks scare people and lead to new support for vaccination, but that comes at the cost of sick kids and potentially dead kids.