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Anti­vac­cine pro­pa­gan­da has been spread­ing. As a result, so has the measles. Anti­vac­cine zealots are not wor­ried by measles out­breaks. Instead, they want even more peo­ple to catch the measles. These anti­vaxxers believe that measles is a harm­less dis­ease that boosts the immune sys­tem. (In real­i­ty, measles is dan­ger­ous main­ly because it dam­ages the immune sys­tem.) Late­ly, anti­vaxxers have been spread­ing the myth that in the old days, par­ents would send their chil­dren to “measles par­ties” at the home of a measles patient. In real­i­ty, some­one from the local board of health would post a quar­an­tine sign on the patient’s home, to pre­vent any “measles par­ty” from tak­ing place.

Measles Quarantine

A 1941 measles quar­an­tine sign from Clifton Heights, Penn­syl­va­nia warned that no one but a doc­tor or nurse was per­mit­ted to enter or leave the house or take any­thing from the house with­out writ­ten per­mis­sion from the Board of Health. Any­one who broke that rule or tam­pered with the sign could be fined up to $100 (which was a lot of mon­ey back then) or jailed for up to 30 days. For this rea­son, “measles par­ties” would have been rare, if they occurred at all.

My Mother’s Measles

My moth­er got measles as a kinder­garten­er in Penn­syl­va­nia in the 1940s. She does not remem­ber the measles quar­an­tine sign on her apart­ment; but she was very sick by the time the measles was diag­nosed, and she had not yet learned to read. She does remem­ber the quar­an­tine sign from chick­en­pox, which she got a few years lat­er. While she was sick, none of her friends were allowed to vis­it. A cousin vis­it­ed before it was clear that my moth­er had measles. This cousin then got the measles.  My moth­er also remem­bers being ter­ri­bly sick from the measles. While she had the measles, her bed­room was kept very dark to pro­tect her eyes. Her par­ents knew that measles could cause blind­ness.

Why Is Measles So Contagious?

Unfor­tu­nate­ly, quar­an­tine is not enough to pre­vent the spread of measles. That’s because at first, a case of measles looks and feels exact­ly like a com­mon cold. It makes the per­son cough. Each cough pro­duces a spray of droplets that can car­ry the virus to oth­er peo­ple. You could catch the measles from sim­ply being in a room where an infect­ed per­son had coughed two hours ear­li­er. Measles is con­ta­gious for about four days before the rash appears and the diag­no­sis of measles becomes obvi­ous. So even though measles patients were quar­an­tined, they were often quar­an­tined too late to keep the dis­ease from spread­ing. For this rea­son, near­ly every­one who was born before 1957 even­tu­al­ly got the measles.

Measles Damages the Immune System

An ordi­nary cold runs its course in about a week, as the immune sys­tem learns how to make anti­bod­ies to that strain of cold virus. But instead of get­ting bet­ter at that point, some­one with measles starts to get much sick­er. That’s because the measles virus infects some of the cells of the immune sys­tem. Instead of killing the measles virus, many of those cells make many new copies of the virus and then die. In oth­er words, the immune sys­tem is bad­ly dam­aged while it is mak­ing the measles infec­tion worse. The lin­ger­ing effects of this dam­age can last for 2 years.

The Measles Vaccine

I was lucky. As a child in the ear­ly 1960s, I was among the first wave of chil­dren to be vac­ci­nat­ed against measles. One of our neigh­bors got measles just before the vac­cine came out. I remem­ber how relieved my moth­er was that we had not been at that girl’s house while she was con­ta­gious and how grate­ful my moth­er was for the vac­cine. In 1971, the measles vac­cine was com­bined into a triple vac­cine that immu­nizes chil­dren against measles, mumps, and rubel­la (MMR). Thanks to the heavy use of this cheap, effec­tive, and remark­ably safe vac­cine, the Unit­ed States was declared free of measles in 2000. Unfor­tu­nate­ly, measles has not yet been erad­i­cat­ed world­wide, so we still see out­breaks that result from import­ed cas­es.

Controlling Measles Outbreaks

Today, a measles out­break is a pub­lic health emer­gency. Measles may spread like the com­mon cold, but it sup­press­es the immune sys­tem like HIV. For this rea­son, most of the deaths due to measles are due to sec­ondary infec­tions, such as pneu­mo­nia. Even with the best of mod­ern med­ical care, measles kills one or two out of every thou­sand patients. The death rate is much high­er among peo­ple with sup­pressed immu­ni­ty, includ­ing can­cer patients. Up to a quar­ter of those peo­ple may die of measles.

Today, when a measles out­break occurs, pub­lic health author­i­ties race to find and help every­one who may have been exposed. If non­im­mune peo­ple can be found with­in 72 hours of expo­sure to measles, they may be giv­en a dose of the MMR vac­cine. Vac­ci­na­tion dur­ing that time peri­od may pre­vent the dis­ease or at least weak­en it. If an unvac­ci­nat­ed per­son can­not be found with­in 72 hours or is preg­nant, is too young for vac­ci­na­tion, or has a sup­pressed immune sys­tem, they can be giv­en a dose of immune glob­u­lin instead. Immune glob­u­lin is a dose of anti­bod­ies from human blood donors. It can be giv­en up to 6 days after expo­sure. Exposed peo­ple who show signs of ill­ness are quar­an­tined, to keep them from spread­ing the dis­ease to any­one else. Dur­ing a measles out­break, chil­dren who have not been or can­not be vac­ci­nat­ed may be banned from pub­lic school or day care facil­i­ties.

Wipe Out Measles, Don’t Spread It!

So “measles par­ties” are a myth. They would even be a crime. The MMR vac­cine is cheap, and it is safe and effec­tive when used as direct­ed. How­ev­er, it is a “live” vac­cine and thus can­not be giv­en to preg­nant women, infants, or peo­ple with a dam­aged immune sys­tem. To pro­tect them, we need to make sure that prac­ti­cal­ly every­one else is immu­nized. If we vac­ci­nate enough peo­ple world­wide, measles will go extinct. After a vac­cine-pre­ventable dis­ease is erad­i­cat­ed, we will not need to vac­ci­nate any­one else against it. Mean­while, anti­vaxxers pose a seri­ous threat to pub­lic health. They are keep­ing the vac­ci­na­tion rate low enough to allow dis­eases to spread, and they con­gre­gate in com­mu­ni­ties and net­works that make it eas­i­er for dis­eases to spread.

A measles virus infec­tion starts off as a res­pi­ra­to­ry infec­tion. Thus, it starts off look­ing and feel­ing like a com­mon cold. But then it takes a dan­ger­ous turn: it infects the immune sys­tem. Measles can cause long-last­ing dam­age to the immune sys­tem. Recent stud­ies have shown that a case of measles can increase a child’s risk of death from oth­er infec­tions for more than 2 years!

Measles is not the only viral infec­tion that is known to pro­duce long-term sup­pres­sion of the immune sys­tem. Anoth­er exam­ple is the human immun­od­e­fi­cien­cy virus (HIV), which is the cause of acquired immun­od­e­fi­cien­cy syn­drome (AIDS). How­ev­er, HIV and the measles virus attack dif­fer­ent kinds of white blood cells, which are the work­hors­es of the immune sys­tem.

HIV attacks the T4 lym­pho­cytes, which are often called T-helper cells. T-helper cells help the oth­er cells of the immune sys­tem rec­og­nize infec­tions and tumor cells. After an HIV-infect­ed person’s T4 cell count drops to dan­ger­ous­ly low lev­els, his or her immune sys­tem is less able to fight many infec­tions and some can­cers (such as Kaposi’s sar­co­ma). Thus, the weak­en­ing of the immune sys­tem gives germs and can­cer cells an oppor­tu­ni­ty to sur­vive and thrive. The result­ing dis­eases are called oppor­tunis­tic.

Peo­ple who are infect­ed by HIV will remain infect­ed for the rest of their lives. In con­trast, most peo­ple who catch the measles will elim­i­nate the measles virus from their body after only a few weeks. Yet the measles infec­tion can cause long-last­ing effects on the immune sys­tem because it wipes out the immune system’s mem­o­ry. Measles virus kills the B mem­o­ry cells, which are the white blood cells that are sup­posed to remem­ber the germs that the body has suc­cess­ful­ly fought in the past. After the B mem­o­ry cells are killed off, the immune sys­tem must relearn much of what it had already learned about dan­ger­ous germs. In the mean­time, the per­son remains at risk for oppor­tunis­tic infec­tions.

HIV is bad, and so is measles. Hav­ing HIV and measles at the same time is par­tic­u­lar­ly bad. The death rate from measles is par­tic­u­lar­ly high in peo­ple who have any oth­er form of immune sup­pres­sion. Unfor­tu­nate­ly, peo­ple who have a sup­pressed immune sys­tem can­not be vac­ci­nat­ed against measles, because the measles vac­cine is a “live” vac­cine. To pro­tect those vul­ner­a­ble peo­ple, we must ensure that prac­ti­cal­ly every­one else is vac­ci­nat­ed against measles.

Most of the deaths due to measles are due to oppor­tunis­tic infec­tions. Thus, it is hard­ly sur­pris­ing that the death rate from measles start­ed to fall after the intro­duc­tion of antibi­otics, even though antibi­otics have no effect on the measles virus itself. Yet even with the best of mod­ern med­ical care, peo­ple still die of measles. Even if they sur­vive, they may be left with per­ma­nent dis­abil­i­ties, such as blind­ness, deaf­ness, and brain dam­age. In some cas­es, the measles virus infec­tion may per­sist in the brain. This per­sis­tent infec­tion leads to a hor­ri­ble dis­ease called sub­a­cute scle­ros­ing panen­cephali­tis (SSPE), which slow­ly destroys the brain. Thus, it leads to a slow and hor­ri­ble death. There is no cure or even any effec­tive treat­ment. For­tu­nate­ly, SSPE can be pre­vent­ed by pre­vent­ing measles.

The vac­cine against measles pro­vides pow­er­ful, long-last­ing pro­tec­tion. If you have received two dos­es of the measles vac­cine, your chances of catch­ing measles go down by about 97%. Thanks to the wide­spread use of the measles vac­cine, measles was elim­i­nat­ed from the Unit­ed States by the year 2000. Unfor­tu­nate­ly, we still have occa­sion­al out­breaks of measles in the Unit­ed States. Most of these cas­es can be traced to some­one who was exposed to measles in some oth­er coun­try. So the best way to pro­tect our­selves against measles is to dri­ve the measles virus into extinc­tion world­wide.

Unfor­tu­nate­ly, many par­ents are refus­ing to allow their chil­dren to be vac­ci­nat­ed against measles. Many of these par­ents have been told that it is bet­ter to allow their chil­dren to get sick, so that they devel­op immu­ni­ty nat­u­ral­ly. In real­i­ty, many of the vac­cine-pre­ventable dis­eases are dan­ger­ous because they sup­press the immune sys­tem. This immune sup­pres­sion is good for the germ that caus­es the dis­ease, but it is bad for the per­son who has the dis­ease. As a result, hav­ing a vac­cine-pre­ventable infec­tion can increase your risk of dying of some oth­er infec­tion.

Many par­ents are refus­ing vac­ci­na­tion because they think that the vac­cines are unnec­es­sary and unsafe. Con­spir­a­cy the­o­rists claim that vac­cines are being pro­mot­ed sim­ply to make mon­ey for the phar­ma­ceu­ti­cal com­pa­nies. Yet if some socio­path­ic “phar­ma bro” real­ly want­ed to make mon­ey on vac­cines, he would make sure that the vac­cine-pre­ventable dis­eases remain in cir­cu­la­tion. Once a dis­ease has been dri­ven into extinc­tion through vac­ci­na­tion, there is no longer any need to vac­ci­nate any­one against it.

Small­pox is extinct. Today, nobody vac­ci­nates chil­dren against small­pox. After polio is extinct, the sales of the polio vac­cine will drop to zero. Like small­pox and polio, measles is caused by a virus that can be found only in human beings. Once we have wiped measles, mumps, and rubel­la off the face of the earth, nobody will need the MMR vac­cine. But it would be mad­ness to stop vac­ci­nat­ing against those dis­eases before then.

For infor­ma­tion about efforts to erad­i­cate measles, vis­it the Measles & Rubel­la Ini­tia­tive.

Dr. S.H.* is a med­ical doc­tor, but she is spread­ing dan­ger­ous false mes­sages about vac­cines. In par­tic­u­lar, she has been mis­rep­re­sent­ing the results of a study of the vac­cines against per­tus­sis (whoop­ing cough). Anti­vac­ci­na­tion activists like to cite sci­en­tif­ic research. They want to cre­ate the impres­sion that they have done their home­work, and that their opin­ions are sci­en­tif­i­cal­ly sound. They often claim to be doing “research.” Yet when you look them up in www.pubmed.com, you find that their pub­li­ca­tion record is thin or nonex­is­tent. Although the anti­vac­ci­na­tion zealots some­times read med­ical jour­nal arti­cles, they typ­i­cal­ly mis­un­der­stand the arti­cles that they dis­cuss. As some­one who has edit­ed text­books and med­ical jour­nals for a liv­ing for more than 25 years, I find their mis­un­der­stand­ings to be irri­tat­ing. Their work is so full of obvi­ous errors of fact and errors in rea­son­ing that it would nev­er have passed muster at any of the sci­en­tif­ic pub­lish­ing com­pa­nies for which I have worked. And yet their work is get­ting plen­ty of hits on the Inter­net!

Dr. H.’s basic argu­ment is this: She thinks that it would be bet­ter for your baby to catch whoop­ing cough, which is a hor­ri­ble and some­times dead­ly dis­ease, than to be vac­ci­nat­ed against whoop­ing cough. This is what whoop­ing cough is like:

Some­times, per­tus­sis is even worse than this. Some new­borns are not strong enough to cough like this. Instead, they sim­ply stop breath­ing and die, with­out warn­ing.

Dr. H. claims that this study by War­fel and cowork­ers shows that hav­ing a nat­ur­al Bor­de­tel­la per­tus­sis infec­tion would be bet­ter than vac­ci­na­tion for pro­mot­ing herd immu­ni­ty. This idea is total non­sense. Whoop­ing cough was once com­mon. It is now rare, thanks to vac­ci­na­tion. Hav­ing more nat­ur­al cas­es of Bor­de­tel­la per­tus­sis infec­tion among the pop­u­la­tion would lead to more ill­ness and more deaths. Bet­ter vac­ci­na­tion cov­er­age leads to less ill­ness and few­er deaths.

The first vac­cine against Bor­de­tel­la per­tus­sis was intro­duced in 1940. At the time, rough­ly 6,000 Amer­i­cans per year were dying of whoop­ing cough. Rough­ly 95% of the dead were chil­dren. Thanks to the vac­ci­na­tion, the death rate dropped sharply. How­ev­er, we are still see­ing occa­sion­al cas­es of whoop­ing cough, even in high­ly vac­ci­nat­ed pop­u­la­tions. Even the immu­ni­ty that results from a nat­ur­al infec­tion lasts for only 4 to 20 years. The pro­tec­tion from vac­ci­na­tion lasts for only about 4 to 12 years. That is why doc­tors urge peo­ple to get boost­er shots against per­tus­sis. If you have par­tial immu­ni­ty to per­tus­sis, you might get only a mild case of the snif­fles from a Bor­de­tel­la per­tus­sis infec­tion. Yet you could pass the bac­te­ria on to some­one else, who could get severe­ly ill.

War­fel and cowork­ers want­ed to answer an impor­tant ques­tion: Is the mod­ern acel­lu­lar per­tus­sis vac­cine less effec­tive than the old-fash­ioned whole-cell vac­cine at pre­vent­ing the spread of Bor­de­tel­la per­tus­sis from per­son to per­son? Since it would be unthink­able to expose human beings to live Bor­de­tel­la per­tus­sis, the researchers used baboons as exper­i­men­tal sub­jects. (Of course, many peo­ple have eth­i­cal objec­tions to the use of ani­mals, and espe­cial­ly pri­mates, as research sub­jects.) Like human beings, baboons get a bad cough from a Bor­de­tel­la per­tus­sis infec­tion.

War­fel and cowork­ers found that both the acel­lu­lar vac­cine and the whole-cell vac­cine were effec­tive for their pri­ma­ry pur­pose, which is to pro­tect the vac­ci­nat­ed indi­vid­ual from get­ting sick after expo­sure to Bor­de­tel­la per­tus­sis. How­ev­er, the whole-cell vac­cine gave the baboons a lit­tle help in clear­ing the Bor­de­tel­la per­tus­sis from their upper res­pi­ra­to­ry tract. The acel­lu­lar per­tus­sis vac­cine did not. It took 21 days for the baboons that received the whole-cell vac­cine to clear the Bor­de­tel­la per­tus­sis from their upper res­pi­ra­to­ry tract. It took unvac­ci­nat­ed baboons and baboons that received the acel­lu­lar vac­cine about twice as long to clear the bac­te­ria from their upper res­pi­ra­to­ry tract.

Dr. H. point­ed out that the Bor­de­tel­la per­tus­sis bac­te­ria could not col­o­nize the baboons that were recov­er­ing from a recent Bor­de­tel­la per­tus­sis infec­tion. From that, she con­clud­ed that nat­ur­al infec­tions were bet­ter for pro­mot­ing herd immu­ni­ty. Yet even the immu­ni­ty pro­duced by a nat­ur­al infec­tion declines after a few years. Also, the basic repro­duc­tion num­ber of per­tus­sis is 5.5, which means that in a sus­cep­ti­ble pop­u­la­tion, a sin­gle nat­ur­al case of per­tus­sis would tend to lead to an aver­age of 5.5 new cas­es of per­tus­sis. So if we relied on nat­ur­al immu­ni­ty to solve our per­tus­sis prob­lem, we would have huge epi­demics of per­tus­sis, as opposed to occa­sion­al small out­breaks.

The study by War­fel and cowork­ers was not about whether to vac­ci­nate against per­tus­sis. It was about which vac­cine to use. In the 1990s, Amer­i­cans switched from the whole-cell vac­cine to the acel­lu­lar vac­cine because the whole-cell vac­cine some­times caused chil­dren to spike a fever. This fever could some­times cause a febrile seizure. These seizures were ter­ri­fy­ing to the par­ents, but they do no last­ing harm to the child. Some oth­er coun­tries con­sid­er this risk of fever to be accept­able because the whole-cell vac­cine may be bet­ter for stop­ping the spread of Bor­de­tel­la per­tus­sis.

Bor­de­tel­la per­tus­sis is found only in human beings. Thus, we might be able to dri­ve this germ into extinc­tion through vac­ci­na­tion. Once it is extinct, nobody will need to get a per­tus­sis vac­cine. Yet to dri­ve per­tus­sis into extinc­tion, we will need a bet­ter vac­cine, one that pro­vides longer-last­ing pro­tec­tion against the car­ri­er state, not just against clin­i­cal dis­ease. In the mean­time, we need for peo­ple to get their chil­dren vac­ci­nat­ed and to keep up to date with their per­tus­sis boost­ers!

 

*I do not use her real name because I do not like to give peo­ple unde­served atten­tion. I explain my rea­son­ing in these two books: