Welcome to our February Public Health Grand Rounds on Measles:

Maintaining Disease Elimination

and Enhancing Vaccine Confidence.

My name is Dr. Tanya Telfair LeBlanc.

I'm with CDC's Office of Science.

Thank you so much for joining us today.

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available for physicians, nurses, pharmacists,

and many other health professionals.

The course code is PHGR10.

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and other Public Health Grand Rounds sessions?

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for information,

resources including a podcast that we call Beyond the Data

and as well as a glossary of terms for each session.

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The full listing is available at cdc.gov/scienceclips.

In addition to our outstanding speakers today,

I'd like to acknowledge the important contributors.

The individuals are listed here but we especially

like to recognize Miss Tiffany Smith, who was invaluable

at putting this whole thing together and worked with us

from the very beginning to the end.

She was absolutely a joy.

It is now my pleasure to introduce

to you today our Director

of the Science Office, Dr. Rebecca Bunnell.

[ Applause ]

>> Good afternoon everyone, and, and thank you so much to those

in the room and those who have joined us remotely.

I want to start by just recognizing the many CDC, state,

and local public health staff

who are currently doing critical work on coronavirus or COVID19.

I know many in the room are also helping to cover for those

who are deployed, so thank you to all of you as well.

As we are seeing in the unfolding events

as COVID19 spreads, disease importations are a constant

threat in today's interconnected world.

Measles, one of the most contagious infectious diseases,

was eliminated from the United States in 2000 thanks to decades

of robust and successful vaccination programs.

However, the global increase of measles in recent years,

in addition to increases in vaccine hesitancy,

pose a risk to US elimination,

especially when unvaccinated travelers acquire

measles abroad.

In 2019, the US saw the highest number of measles cases

in a single year since 1992,

with nearly 1300 confirmed cases.

Over 73% of these cases were linked to a breaks

in New York affecting under vaccinated communities.

Sustained transmission of almost 12 months nearly led to the loss

of our nation's measles elimination status.

Today's session of Grand Rounds will focus on measles

in the United States and the response to and lessons learned

from the outbreaks in New York in 2018 to 2019.

You'll also hear about the CDC's national strategy

for strengthening vaccine confidence

and increasing vaccination coverage to protect our nation

from vaccine-preventable diseases like measles.

The 2019 measles response in New York and in New York City

and beyond is an example of the best of Public Health.

We will need to draw on that kind of talent and that kind

of commitment as we collectively respond

to today's challenges with COVID19.

On that note, I will pass it back to, to Dr. LeBlanc

to open up our session.

Thank you again.

[ Applause ]

>> Our first speaker today is Dr. Manisha Patel

who we affectionately refer to as Moe.

She is a medical officer

and a domestic measles team lead with NCIRD.

Dr Patel?

>> Good afternoon.

So, this first presentation is going

to cover measles in the United States.

Measles is one of the most contagious

of the vaccine-preventable diseases.

In fact a single case of measles can infect 12 to 16 other people

in a, within a totally susceptible population.

It's an acute viral rash illness that classically presents

with high fever, cough, coryza,

or runny nose and conjunctivitis.

The incubation period is 10 to 14 days but rash can appear

as early as 7 days and lasts, or as late as 21 days.

And the infectious period starts four days before the rash

appears and through four days after rash onset.

And the rash typically appears on the face and the hairline

and then spreads downwards.

Measles complications are more common in younger children

and adults and can range from less severe like otitis media

to more severe complications like encephalitis and death.

Sub-acute sclerosing pan encephalitis is a rare

but fatal neurologic complication that occurs seven

to ten years after the initial measles infection

and it typically presents with these minor behavioral changes

that progress with myoclonic jerks and dementia

and eventually to death over the course of months to years.

Usually it's children who are infected when they are less

than two years of age who are at highest risk.

This is a really devastating complication.

Fortunately, the measles-mumps-rubella,

or MMR vaccine, is highly effective against measles

and it's complications.

It has a one dose vaccine effectiveness of 93%

and a two dose VE of 97%.

It has an excellent safety profile.

Common side effects such as fever and rash are usually mild

and resolve spontaneously.

Serious adverse events are extremely rare.

Children and adolescents need two doses of MMR

and most adults need only one dose

of MMR unless they have other evidence of immunity.

High-risk adults such as healthcare personnel,

post high school students

and international travelers need two doses.

Vaccination of US residents traveling abroad is really

critical and as you will see later in my talk, they account

for the majority of measles introductions

into the United States.

So two points about travel.

First, travelers twelve months of age

or older should have two documented doses

of MMR vaccine before they leave for their trip.

So, this means that you can decrease the interval

between the first and second dose to a short

as 28 days if you need to.

And then the second important point is that infants 6

to 11 months of age should receive one dose

of MMR before they travel.

This dose does not count as part of their routine recommendations

and so they will need two doses of MMR after they turn 1.

So, high vaccine effectiveness

and the excellent safety profile allowed for the rollout

of several key policy changes slash initiatives in the '80s

and '90s that increased MMR vaccine coverage

in the United States.

This includes the recommendation

of the second dose of MMR in 1989.

The implementation of the vaccine for children's program

which allowed for wider access to vaccination.

And commitment by the Pan-American Health Organization

in other countries in the region

to stop endemic measles transmission

through large-scale vaccination efforts throughout the Americas.

And all of this led to measles being eliminated

in the United States in 2000.

So, what is really key

for measles during the post elimination years

which is defined as 2001 and on is that most measle cases are

in unvaccinated persons.

And this is shown here in orange.

The other important point is that the highest incidence is

in infants who are 12 to 15 months of age.

And this is really important for providers to be aware of so

that they are vaccinating infants against measles as soon

as they turn 12 months of age.

So, I mentioned that the majority of or two-thirds

of measles importations are among US residents

in more recent years.

And the fact that these importations are occurring

in unvaccinated US travelers

who are acquiring measles infection abroad

and then developing disease and in some instances transmitting

to others when they return

to the United States really underscores the importance

of ensuring that providers are vaccinating their patients

before they travel internationally.

So, even though the US is continually getting measles

importation and there have been 747 importation from 2001

through 2019, most importation are not associated

with outbreaks.

And this has to do largely

because of the high nationwide MMR vaccination coverage

in the United States but also

because of the extraordinary efforts from state

and local health departments

who are responding rapidly to every single case.

So, the, in general the reported measles incidents has remained

less than one per million and that's shown

by the red dotted line there.

And, and this is an indicator of good measles control.

But you can see that in more recent post elimination years we

are seeing an increase in the number

of reported measles cases, particularly

in 2014, 2018, and 2019.

So why is this happening?

Well, one major contributor for the increase

in domestic measles is the increase in global measles

which tripled in 2019 and all of the

WHO of regions have reported measles cases.

But the European and African regions particularly had major

outbreaks occurring in the Ukraine and in Madagascar

which is contributing to that blue region for African region

and the red for the European region.

So, while the global measles activity remains high,

the United States will be at continued risk for measles

and these importations can land anywhere in the United States

but it is more concentrated in states

that have major ports of entry.

And then when you overlay these importations

with geographic areas that are highly dense

and have lower vaccination coverage, you're going

to have rapid spread of measles throughout a community leading

to large outbreaks.

And just as a reminder - the herd immunity threshold

for measles, which is the proportion of a population

that needs to be immune to prevent transmission, is high.

It's between 92 and 94%.

Since 2001, 158 outbreaks have been reported

in the United States but most of these outbreaks are limited

in size and duration, with 5 cases per outbreak

and the median duration of 23 days.

But you can see that in more recent years

that there are larger outbreaks that are being reported

and these shown in red are the outbreaks

that are of 50 or more cases.

And then if you look closer at those outbreaks,

the seven that I showed in red in the previous slide,

there are two points that stand out.

First, these outbreaks are occurring

in close-knit communities.

And second, these outbreaks are lasting for longer

than what we had seen when you compared it

to earlier post elimination years.

The last row shows the two outbreaks New York City

in New York State which started in 2018.

New York City and New York State were especially concerning,

not only because of the large number of outbreaks

that were reported but because of the sustained duration

of these outbreaks with transmission lasting for nine

and a half months in New York City and ten

and a half months in New York State.

And if transmission had lasted for 12 or more months,

twelve months or longer,