As the Number of Unvaccinated Americans Grows, Measles and Whooping Cough Make a Comeback

The national average is still low, but some states are growing increasingly vulnerable to preventable diseases.

Public school student Julio Valenzuela, 11, smiles as he gets a Measles, Mumps and Rubella vaccination (MMR), at a free immunization clinic for students before the start of the school year, in Lynwood, California August, 27, 2013. Nurses are immunizing children in preparation for the first day of public school on September 3. The clinic offers the mandatory vaccinations for school children against diphtheria, tetanus, pertussis, polio, hepatitis B, MMR (measles, mumps, rubella) and chickenpox . AFP PHOTO / Robyn Beck 
National Journal
Sarah Mimms
June 3, 2014, 1 a.m.

Doc­tors across the coun­try are hear­ing more and more com­plaints about dis­eases we typ­ic­ally as­so­ci­ate with his­tory books or sud­den, pixelated deaths on The Ore­gon Trail. Measles, a dis­ease that was es­sen­tially erad­ic­ated in the United States in 2000, is spread­ing, with 288 cases rep­res­ent­ing 15 sep­ar­ate out­breaks re­por­ted na­tion­wide just in the first five months of this year. That’s a 20-year high. Mean­while, pertussis, or whoop­ing cough, cases are up 24 per­cent over last year.

And the Cen­ters for Dis­ease Con­trol and Pre­ven­tion is pin­ning the blame on par­ents who won’t vac­cin­ate their chil­dren.

The United States elim­in­ated measles in 2000 (mean­ing that the coun­try stopped ex­per­i­en­cing home-grown measles out­breaks) thanks in large part to the pop­ular­ity of the measles, mumps and ru­bella vac­cine, known as MMR. Pertussis has been much more dif­fi­cult to erad­ic­ate, al­though the vac­cine is also a re­quire­ment for entry to most schools.

But as the num­ber of people in the United States who re­quest ex­emp­tions to avoid vac­cin­at­ing their chil­dren for either re­li­gious or philo­soph­ic­al reas­ons con­tin­ues to grow, the num­ber of people who are at risk of con­tract­ing measles and pertussis is in­creas­ing along with it.

And that trend is ex­pec­ted to con­tin­ue through the year. As Amer­ic­ans travel abroad, par­tic­u­larly those who are un­vac­cin­ated, the chances of their bring­ing measles or pertussis back with them are ex­tremely high. “We haven’t yet be­gun the spring and sum­mer travel sea­sons, which is when we usu­ally have a lot of [measles] cases here in the U.S,” Dr. Anne Schuchat, the dir­ect­or of CDC’s Na­tion­al Cen­ter for Im­mun­iz­a­tion and Res­pir­at­ory Dis­eases, warned in a con­fer­ence call with re­port­ers last week.

Measles is wildly con­ta­gious, with the al­most cer­tainty that any un­vac­cin­ated per­son who is ex­posed to the dis­ease will con­tract it. Just look to Vir­gin­ia, where one in­fec­ted child’s pub­lic sched­ule over an eight-day peri­od has put the en­tire Vir­gin­ia-Mary­land-D.C. area on alert. “If you or your fam­ily haven’t been vac­cin­ated and you en­counter the measles vir­us, they will get sick,” Schuchat said.

Nearly half of the measles cases so far this year have oc­curred in Ohio, where 138 in­di­vidu­als have re­por­ted con­tract­ing the dis­ease. Al­though the state has a re­l­at­ively high num­ber of vac­cin­ated people, the out­break has been sweep­ing through the state for months be­cause of a few isol­ated but large pock­ets of un­vac­cin­ated in­di­vidu­als.

The out­break began last Oc­to­ber when a group of Amish men traveled to the Phil­ip­pines (which is ex­per­i­en­cing a massive out­break af­fect­ing at least 32,000 people) on a mis­sion trip and brought the dis­ease back with them. Be­cause most Amish com­munit­ies don’t be­lieve in vac­cin­a­tion, measles is spread­ing from one to the next. But it’s not just the Amish who are suf­fer­ing.

One of the ma­jor be­ne­fits of vac­cin­a­tion is what’s called “herd im­munity.” When the vast ma­jor­ity of the people in a giv­en com­munity are vac­cin­ated, the chances of those who can­not be vac­cin­ated of get­ting a par­tic­u­lar dis­ease goes down drastic­ally. When a great­er pro­por­tion of a com­munity isn’t vac­cin­ated, say in an Amish com­munity or a neigh­bor­hood of par­ents who buy in­to the anti-sci­entif­ic claims of a link between vac­cin­a­tions and child­hood aut­ism, the chances of the dis­ease spread­ing to those who can­not be vac­cin­ated grow.

A small, but sig­ni­fic­ant por­tion of the U.S. pop­u­la­tion can­not be vac­cin­ated either be­cause they are too young, they’re al­ler­gic to the vac­cine or a com­pon­ent of it (latex, eggs, etc.), they are preg­nant, or be­cause they have can­cer, HIV, or an­oth­er im­mun­ode­fi­ciency.

Measles is dan­ger­ous, par­tic­u­larly for those with preex­ist­ing med­ic­al con­di­tions. Fif­teen per­cent of people who have con­trac­ted measles this year have wound up in the hos­pit­al, ac­cord­ing to the CDC. For those who have, pneu­mo­nia has been the most com­mon com­plic­a­tion. So far, there are no re­por­ted deaths.

Measles is also one of the more deadly dis­eases for chil­dren, par­tic­u­larly for kids who are too young to be vac­cin­ated. Typ­ic­ally, doc­tors sug­gest that chil­dren get their first measles vac­cine at 12-15 months and the second dosage be­fore en­ter­ing school, around 4-6 years of age. Among the un­vac­cin­ated, roughly 6 per­cent of cases re­por­ted this year oc­curred in chil­dren too young to be vac­cin­ated, while an­oth­er 17 per­cent af­flic­ted chil­dren un­der the age of 4, who are too young to have re­ceived both doses, ac­cord­ing to the CDC.

Ninety per­cent of measles cases so far this year have af­fected those who are un­vac­cin­ated or in­di­vidu­als who were un­sure of their vac­cin­a­tion status, ac­cord­ing to Schuchat.

In­cid­ences of whoop­ing cough are also grow­ing. Already this year, 8,521 cases have been re­por­ted, with most of them in Cali­for­nia, Ohio, and Texas. That rep­res­ents nearly a 50 per­cent in­crease from April, when the CDC an­nounced that pertussis cases had ris­en 24 per­cent over the same peri­od in 2013.

Like measles, pertussis can lead to pneu­mo­nia and can be deadly in ba­bies. Be­cause the dis­ease is highly con­ta­gious, those who are not vac­cin­ated can eas­ily pass it on to in­fants and to oth­er un­vac­cin­ated in­di­vidu­als.

Over­all, Schuchat said the coun­try is do­ing re­l­at­ively well in vac­cin­at­ing chil­dren. Ninety-nine per­cent of Amer­ic­an chil­dren have re­ceived at least one vac­cin­a­tion, though the num­ber of chil­dren who are fully vac­cin­ated is much smal­ler. Only 68.4 per­cent of chil­dren between 19-35 months had re­ceived a full com­bin­a­tion of vac­cin­a­tions in 2012.

The num­bers also vary by dis­ease. Between 2008 and 2012, the num­ber of chil­dren between 19-35 months old who re­ceived all four dosages of the pertussis vac­cine de­clined 2 per­cent­age points, to 82.5 per­cent. The num­bers for the MMR vac­cine were bet­ter, fall­ing only 1 per­cent­age point dur­ing the peri­od to 90.8 per­cent.

Al­though the na­tion­al av­er­age of in­di­vidu­als who have re­ques­ted non­med­ic­al ex­emp­tions for vac­cin­at­ing their chil­dren in the United States has re­mained low, there are com­munit­ies in which anti-vac­cin­a­tion sen­ti­ment is grow­ing. And that puts those who med­ic­ally can­not be vac­cin­ated, or are too young, at great­er risk.

In Ore­gon, in par­tic­u­lar, nearly 7 per­cent of kinder­gart­ners last year were not vac­cin­ated for philo­soph­ic­al and re­li­gious reas­ons. In Idaho, Michigan, and Ver­mont, more than 5 per­cent of kinder­gart­ners avoided vac­cin­a­tion for non­med­ic­al reas­ons. Out­breaks in those com­munit­ies could spread eas­ily and en­danger chil­dren across those states.

Some re­li­gious com­munit­ies, in­clud­ing the Amish, op­pose vac­cin­at­ing on ideo­lo­gic­al grounds. But there are also low-in­form­a­tion smear cam­paigns be­ing run across the coun­try en­cour­aging par­ents not to vac­cin­ate their chil­dren. Not­ably, act­ress Jenny Mc­Carthy be­came a ma­jor op­pon­ent of vac­cines, link­ing them, falsely, to her son’s aut­ism in nu­mer­ous me­dia ap­pear­ances and in an ac­com­pa­ny­ing book. Her then-boy­friend, act­or Jim Car­rey, made sim­il­ar ar­gu­ments, bring­ing more celebrity to the cause.

“We know there are com­munit­ies where large num­bers of in­di­vidu­als have de­cided not to be vac­cin­ated,” Schuchat said, but ad­ded that al­though a num­ber of par­ents have ob­jec­ted to vac­cin­a­tion on philo­soph­ic­al, not re­li­gious grounds, the sup­posed link between aut­ism and vac­cin­a­tion hasn’t res­ul­ted in stat­ist­ic­ally sig­ni­fic­ant up­tick in un­vac­cin­ated chil­dren.

For now, the CDC is push­ing even harder for chil­dren and adults to get vac­cin­ated, and ur­ging those who aren’t sure about their status to get an ad­di­tion­al vac­cine. That way, Schuchat hopes, they can con­tain the prob­lem. “This year we are break­ing re­cords for measles,” she said, “and it’s a wake-up call, be­cause we don’t have to let this get even worse.”