Tag: travel vaccines

How Do You Know If You Have Measles Immunity?

With all of the measles cases, you might be wondering if you have immunity to measles?

Are you worried that you might get measles?

Should you get a booster dose of MMR?

Or a titer test?

How Do You Know If You Have Measles Immunity?

Fortunately, most of us can feel confident that we do have measles immunity and that we won’t get caught up in any of the ongoing outbreaks.

Why?

If you have had two doses of MMR, then you can be confident that you have measles immunity.
If you have had two doses of MMR, then you can be confident that you have measles immunity.

Because we are vaccinated and protected!

If you haven’t had two doses of MMR (or any measles containing vaccine since 1967), then understand that two doses is your best protection against measles.

Is There a Blood Test for Measles Immunity?

What about titer tests?

While there is a blood or titer test for measles immunity, it isn’t routinely used.

The one situation in which a measles titer test might be useful though, is for those born before 1957 to confirm that they really had measles.

For others considering a titer test in place of vaccination, it is typically better to just get another dose of MMR, but only if you haven’t already had two doses.

Why Was My Measles Titer Negative?

A positive measles titer does mean that you are immune, but what about a negative measles titer?

“For HCP who have 2 documented doses of MMR vaccine or other acceptable evidence of immunity to measles, serologic testing for immunity is not recommended. In the event that a HCP who has 2 documented doses of MMR vaccine is tested serologically and determined to have negative or equivocal measles titer results, it is not recommended that the person receive an additional dose of MMR vaccine. Such persons should be considered to have presumptive evidence of measles immunity. Documented age-appropriate vaccination supersedes the results of subsequent serologic testing.”

Immunization of Health-Care Personnel: Recommendations of the Advisory Committee on Immunization Practices (ACIP)

If you have had two doses of MMR and have a negative measles titer, you don’t need another dose of MMR. You are likely immune, even with that negative titer.

“Most vaccinated persons who appear to lose antibody show an anamnestic immune response upon revaccination, indicating that they are probably still immune.”

Epidemiology and Prevention of Vaccine-Preventable Diseases

And since you would need a second dose if you had a negative titer after having just one shot, you might as well just get the second dose instead of checking your titer.

Do You Need a Measles Booster?

Have you had two doses of MMR?

If so, then you don’t need another dose.

The second dose isn’t technically a booster anyway. It is just for those who might not have responded to their first dose.

And two doses of MMR are about 97% effective at preventing measles.

That’s why most of the people in measles outbreaks are unvaccianted.

Neither primary nor secondary (waning immunity) vaccine failure are common with the measles vaccine.

What’s the biggest issue with the MMR? Folks who are still too scared to get their kids vaccinated and protected!

More on Measles Immunity

What Is Your Protocol to Stop Measles Before Kids in Your Office Get Exposed?

Measles outbreaks have reached record levels this year. Unless you’re prepared, with a strict protocol to stop measles, that could mean that someone could get exposed in your office.

“Many of today’s physicians may never have seen a patient with measles— a disease that can cause serious complications in infants, young children, and adults. CDC is urging all physicians to “think measles” when evaluating patients who have fever and rash, and to know what to do to prevent, control, and report measles cases.”

CDC Asking Physicians to “Think Measles” and Help Stop the Spread

Have you ever seen a child with measles?

What Is Your Protocol to Stop Measles Before Kids in Your Office Get Exposed?

To help everyone understand how important it is to think about measles and prevent unnecessary exposures, it can help to understand what happens when a child with measles does go to their pediatrician, an urgent care center, or the ER.

Part of your protocol to stop measles will be making sure th unvaccinated children exposed to measles are quarantined for at least 21 days.
Unvaccinated children exposed to measles are quarantined for at least 21 days.

Since measles is so contagious and can remain infectious for up to two hours after a person has left a room, with each measles case, you will have to:

  • isolate the person with measles (or suspected measles) in a negative pressure isolation room. If that’s not possible, at least have the person wear a mask in their own private room and/or schedule them at the end of the day, bypassing the waiting room. You might even go out to their car for a quick interview and exam before they come into the office.
  • not use that exam room for at least two hours after the person with measles leaves.
  • report the case to your local health department ASAP, as they will likely have more extra resources to help you manage your patient.
  • locate everyone who could have been exposed, including anyone who was in the same area as the suspected case or entered the area over the next two hours. If they aren’t already immune, these folks might need immune globulin (younger than six months or immunocompromised) or a dose of MMR. They will probably also be quarantined to make sure they don’t develop measles and expose others.
  • only allow those who are immune to measles (two doses of MMR or natural immunity) to take care of the suspected case. Everyone should still wear an N95 respirator or at the very least, a general facemask, just in case.
  • limit anyone else’s exposure as you work to confirm that they have measles (PCR testing of throat swab and urine), provide supportive care as necessary, or quarantine them at home.

Unfortunately, it usually ends up being more than a single exam room that has to be closed when a child shows up with measles. After all, before they got to that exam room, they were probably in the waiting room and other general areas of the office.

And that’s why you will want to have a protocol in place to avoid or minimize these exposures.

Don’t Spread Measles

Of course, that starts with trying to get everyone vaccinated and protected, including an early dose of MMR when appropriate, so that your patients don’t get measles in the first place!

“Failure to promptly identify and appropriately isolate measles cases has led to the investigation of hundreds of healthcare contacts this year. Measles transmission has occurred in emergency departments and other healthcare settings, including transmission to one healthcare worker.”

Recommendations for Measles Case Identification, Measles Infection Control, and Measles Case and Contact Investigations

Next, make sure everyone understands how to recognize the signs and symptoms of measles. Otherwise, some of these kids might unexpectedly end up in your office when they are sick.

The classic measles rash, which begins on the face, typically doesn't begin until these kids have had fever for two or three days.
The classic measles rash, which begins on the face, typically doesn’t begin until these kids have had fever for two or three days. Photo by Jim Goodson, M.P.H.

Think that’s easy? You just watch out for kids with a fever and a rash, right?

Wrong.

If you wait until they have the classic measles rash, you will likely miss the diagnosis the first time they come to your office. Remember, the rash typically doesn’t show up until they have already had a fever for three or four days.

Unfortunately, these kids are contagious well before they have a rash. They are even contagious before they have a fever and know they are sick.

As part of your protocol to stop measles, post a warning sign before parents come into your office.
As part of your protocol to stop measles, post a warning sign before parents come into your office.

So you should suspect measles in kids:

  • with a high fever and cough, coryza, and conjunctivits, even if they don’t yet have a rash
  • with classic measles symptoms who have had a possible exposure. This includes kids who recently traveled out of the country (get a travel history), had contact with international travelers, or just because there are a lot of cases in your area.
  • who are unvaccinated or not completely vaccinated, with two doses of MMR. Keep in mind that even fully vaccinated kids can sometimes get measles though.

And then, if you suspect that a child has measles, work to limit their exposure to others. Patients should know to call ahead. Staff at your office, lab, or the ER should be alerted and ready to see anyone with suspected measles. That way the family knows to wear a mask before going inside.

Ideally, if you have a strong suspicion that the child has measles, this visit will occur in a facility with a negative pressure airborne infection isolation room.

What’s the problem with this kind of protocol?

Lots of kids have fever and rashes! And since you can’t send everyone that calls with adenovirus, roseola, or hand, foot and mouth disease to the ER, part of your protocol should likely be that a health care professional carefully assesses the child’s signs, symptoms, and risks for measles before deciding what to do.

Mostly, be suspicious if a child has returned from a trip oversees, especially if they are unvaccinated, and they have a febrile illness.

More on Your Protocol to Stop Measles Before Kids in Your Office Get Exposed

Who Is ‘Patient Zero’ in the 2019 Measles Outbreaks?

As we climb to ever higher case counts in the 2019 measles outbreaks, you might be wondering who to blame?

Who started the outbreaks?

How Does ‘Patient Zero’ Start a Measles Outbreaks?

As you have likely guessed, there is no one person who started all of this year’s outbreaks. Well, maybe there is. After all, who is responsible for so many folks not getting vaccinated?

In most cases though, we do know who started the outbreak – the “patient zero.”

And it is almost always an unvaccinated traveler, typically a US resident, who got measles abroad and brought it back into the U.S.

What happens next? If they expose a lot of people in an area with low vaccination levels, then you can expect a big outbreak. On the other hand, if most people are vaccinated and protected, you might not see any more cases in that area.

Who Is ‘Patient Zero’ in the 2019 Measles Outbreaks?

So who are these folks?

This year's measles cases are spread out in outbreaks in 26 different states. So there isn't only one patient zero...
This year’s measles cases are spread out in outbreaks in 26 different states. So there isn’t only one patient zero…

They aren’t people who had been recently vaccinated are giving others vaccine strain measles through shedding! That doesn’t happen.

Instead, at least 44 people triggered separate outbreaks after traveling from the Philippines, Ukraine, Israel, Thailand, Vietnam, Germany, Algeria, France, India, Lithuania, Russia, and the United Kingdom.

The 2019 measles outbreaks include the:

  • Rockland Outbreak – an unvaccinated teenager brought measles to Rockland County in September 2018 from Israel.
  • Brooklyn Outbreak – the initial case in Brooklyn was unvaccinated and got measles in October 2018 on a visit to Israel. Measles was reintroduced into the community at least six other times though, four cases were also acquired on visits to Israel, while two people got measles from the U.K., and one from Ukraine.
  • Pacific Northwest Outbreak – a child who had traveled from Ukraine to Washington was the first confirmed case and likely source of the Pacific Northwest measles outbreak.
  • Michigan Outbreak – a traveler from Brooklyn started the Michigan measles outbreak.
  • Northern California Outbreak – a “cluster” of cases in Butte, Tehama, and Shasta counties that was started by a traveler who had recently been to the Philippines.
  • Puget Sound Outbreak – triggered by a Canadian resident who traveled to Seattle, after completing a trip to Japan and New York, where he likely became infected.

Why is it important to find patient zero and know who started an outbreak?

Mostly, it helps you find everyone who was exposed to measles and hopefully limit and quickly control the outbreak.

Make sure you are fully vaccinated and protected, with two doses of MMR, before your next trip so that you're not the next patient zero.
Make sure you are fully vaccinated and protected, with two doses of MMR, before your next trip.

It should also remind everyone that the easiest way to avoid getting measles and avoid triggering an outbreak, is to get vaccinated and protected, especially if you plan on traveling out of the country.

More on Who Is ‘Patient Zero’ in the 2019 Measles Outbreaks?

Dengvaxia for Dengue Fever

Dengvaxia was recently approved by the FDA after being available in other countries since about 2015.

“Indicated for the prevention of dengue disease caused by dengue virus serotypes 1, 2, 3 and 4. DENGVAXIA is approved for use in individuals 9 through 16 years of age with laboratory-confirmed previous dengue infection and living in endemic areas.”

Wait.

Dengue is endemic throughout the tropics and subtropics, including most of the Caribbean.
Dengue is endemic throughout the tropics and subtropics, including most of the Caribbean.

It’s only for people who have already had a dengue infection before?

Dengvaxia Controversy

Unfortunately, Dengvaxia “performs differently in seropositive versus seronegative individuals.”

“In areas of 70% dengue seroprevalence, over a 5-year follow-up, for every 4 severe cases prevented in seropositive, there would be one excess severe case in seronegative per 1,000 vaccinees; for every 13 hospitalizations prevented in seropositive vaccinees, there would be 1 excess hospitalization in seronegative vaccinees per 1,000 vaccinees.”

WHO on Questions and Answers on Dengue Vaccines

If you have never had dengue before and you are vaccinated, you are at risk for a severe infection if you do get dengue. On the other hand, if you are unvaccinated, you are at even greater risk of getting dengue, a life-threatening infection. Fortunately, the first episode of dengue is usually fairly mild.

The problem occurs if your antibody levels have dropped enough, which can cause you to have a severe case of dengue the second time. The process is called antibody-dependent enhancement and has to do with antibody levels, either natural or vaccine induced. So it can occur whether or not you are vaccinated, although getting Dengvaxia, an attenuated, live vaccine, can act as a primary dengue infection.

“These differing epidemiological features support the conclusion that antibody dependent enhanced (ADE) dengue disease occurred in seronegatives who were sensitized by vaccine. As hospitalizations continue to occur in all age groups Dengvaxia consumers should be warned that sensitized vaccinated seronegatives will experience enhanced dengue disease into the forseeable future.”

Scott Halstead on Dengvaxia sensitizes seronegatives to vaccine enhanced disease regardless of age.

It is something that dengue researcher Scott Halstead warned folks about as soon as he saw the first published study on Dengvaxia.

But why would you need a vaccine if you have already had dengue?

“In humans recovery from infection by one dengue virus provides lifelong immunity against that particular virus serotype. However, this immunity confers only partial and transient protection against subsequent infection by the other three serotypes of the virus. Evidence points to the fact that sequential infection increases the risk of developing severe dengue.”

WHO on Dengue control

There are four serotypes of dengue.

So if you aren’t vaccinated, you are at risk to get dengue multiple times.

Tragically, about 800,000 children in the Philippines were given Dengvaxia in a universal immunization program without checking to see if they had dengue first. And it likely led to some severe cases of dengue and deaths. This led to the vaccine being banned in that country and is thought to be one of the causes behind their current measles outbreak, as their Dengvaxia controversy led to more vaccine hesitancy.

And it will lead to more folks getting dengue. Instead of a ban, they should likely be more picky about who they give the vaccine to, either confirming that recipients have already had dengue (titer test) or only giving the vaccine to older kids.

Dengvaxia for Dengue Fever

Do you need Dengvaxia?

Remember, Dengvaxia is only for those living in endemic areas and in the United States, dengue is only endemic in the U.S. territories of American Samoa, Guam, Puerto Rico, and the U.S. Virgin Islands.

Do you need Dengvaxia if you are simply traveling to one of these areas?

Since Dengvaxia is not approved for those who haven’t had a dengue infection before, you likely wouldn’t get it just for traveling to an endemic area, unless perhaps you routinely travel to an endemic area and have had dengue already. A titer test can confirm a previous dengue infection, but there is no indication to get vaccinated for travel yet.

Also, while in other countries it is available for use between 9 and 45 years, in the United States, Dengvaxia is only approved for children between 9 and 16 years of age.

More on Dengvaxia for Dengue Fever