Measles immunization: 12 or 15 months?

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1038

PEDIATRICS

Vol. 62 No. 6 December 1978

and gasoline engines-to children, who lack both the maturity of judgment and the “motor skills” to control these vehicles?

There are other reasons for justified

exaspera-tion. Not only the excitement of high speeds gets into kids’ blood-the effiuvia from a forest of

tailpipes does also. I doubt that tetraethyllead,

sulfur dioxide, and carbon monoxide from a

weekend of trail-biking or snowmobiling en-hances a child’s learning capacity. That the stuff is not recommended for healthy lungs, there’s no question.

\Vhat of the values that our niotor-hungry

children are imbibing? Speed and power, not

esthetics or self-achievement, are the important goals. Independence and autonomy, not sharing

and cooperation, are stressed. Terrorizing other

people is more fun than interacting constructively with them. High-priced activities, like steering a

motorboat or bouncing on a snowmobile, are

exciting; inexpensive pursuits, like hiking or

swimming, are dull. Environments are prized

according to the availability of roads to haul

minibikeladen trailers and fuel stations to feed

gasoline tanks. Tranquility, isolation, and natural

beauty become quaint irrelevancies. Rather than drawing closer to the earth, appreciating its

smells and sights and sounds through noncon-sumptive and nondestructive pursuits, the object

is to get across territory in the fastest, loudest, and scariest way possible.

Finally, how much can a family share when all

its members are driving off in different directions

on their own vehicles? If parents bought their kids

skis instead of snowmobiles, bicycles instead to

trailbikes, the money saved could pay for more

life-enhancing motor activities-dance classes or

piano lessons, for instance. Better yet, parents

might save enough money to be able to spend a few extra nights or weekends with their children,

skiing, walking, or just talking with each other.

Kids might discover that their parents are more interesting people than they suspected, and parents might find that their children have much to teach them.

If I had my way, child-sized motor vehicles simply wouldn’t be nianufactured. Just as many states have outlawed the sale of dangerous

fire-works, so, too, could federal or state legislation

forbid the sale of these vehicles. Even without

additional legislation, the Consumer Product Safety Conilnission has the power to recall and

ban hazardous products. Perhaps if they received

enough letters from physicians treating children with motor-vehicle related injuries, they’d be

prompted to act. Finally, no person should be allowed to pilot aiiij motor-driven vehicle-on or off public roads or across waterways or in the

air-without a license.

Until these vehicles are no longer available to children, we as pediatricians can provide antici-patory guidance to parents, to steel them for the inevitable demands of their children for these “presents. ‘ ‘ Children will not become

demoral-ized if they’re demotorized, nor will they be

emotionally or physically deprived. Just as tod-diers will desert their fancy “educational” toys for hours of blissful play with battered pots and pans,

so will our adolescents find more gratifying, and

safer, pursuits. What’s required is for parents to

stop living out their fantasies, expiating their guilt, or avoiding their responsibilities by

lavish-ing on their children spirit-stifling, environment-destroying, hazardous, and expensive “toys.”

LAWRENCE R. BERGER, M.D.

Robert Wood Johnson Clinical Scholars Program,

University of Washington HQ-18

Seattle, WA 98105

REFERENCES

1. Boating Statistics, 1976, publication CG-357. US Coast Guard, May 1977.

2. \‘ationa! Electronic injury Surveillance System, Matrix

Report. US Consuiiier Product Safety Commission, Bureau of Epidemiology, February 1978.

Measles

immunization:

12 or 15 months?

The objective of immunization is to reduce morbidity produced by natural illness. Ideally, we

would like to eradicate natural infection. This goal, which has been presumably accomplished for smallpox, has clearly eluded us in the case of

measles. Eradication requires reduction in the

number of susceptible subjects to the point where transmission of natural infection is interrupted. It

is clear in the case of measles that we continue to have pockets of susceptible subjects that permit

perpetuation of this disease. Clusters of cases

occur in neighborhoods where immunization levels are low and in situations where susceptible

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COMMENTARIES

1039

subjects are brought together in close contact,

such as in high schools, colleges, and military installations.

The timing of iinmunization is #{149}of critical

importance in reducing the susceptible popula-tion. Immunization must i)e carried out at an age

when it is most likely to be successful and at a

time when children are most likely to be seen by the pediatrician. The slightly higher rate of

successful immunization that niay be achieved by

immunizing older children imist be balanced

against the possibility that children may be

infected l)efore immunization or that they may be

less likely to return at a later date than an earlier one for immunization. The Committee on

Infec-tious Diseases of the American Academy of

Pedi-atrics (Red Book Coiniiiittee) has stated that “the

recoin mended age for measles

mi

iminization tinder usual circumstances is at or after 15 months of age. “ ‘ This recommendation has been ques-tioned by many in this country and abroad. Our

neighbors to the north, for instance, have elected to continue to inimunize Canadian children

against measles at 12 months of age.

New recommendations for measles

immuniza-tion were issued in June 1977 following the

largest epidemic of measles we had experienced

in this country since 1971. In examining these

data, however, it was clear that school-aged

children were those most affected. Sixty-five

percent of the reported cases, moreover, occurred

in children 10 years of age or older. During the

epidemic, there was but a minimal increase in cases in preschool children. What was most

disconcerting was the observation that many of the school-aged children had a history of previous

inmunization. It was found that a large

propor-tion of those previously immunized in whom measles developed had received vaccine before their first birthday. There was some suggestion,

moreover, that those immunized at 12 or 13

months were less well protected than those immunized later.’ It is iniportant to reemphasize

that the high attack rate in school-aged children

compared to that in younger children does not

indicate loss of vaccine-induced immunity. There was no relationship, for instance, between time since immunization and vaccine failure rate.’

It is clear from the experience during the 1977

epidemic that there was a problem at the time school-aged children received their vaccine that resulted in a surprising nunhl)er of vaccine fail-tires. In addition to age at immunization, other

factors (e.g., the use of immune serum globulin with further attenuated vaccine, improper

stor-age of vaccine, and administration of killed vaccine before administration of live vaccine) ulay have contributed to the disappointing performance of measles vaccine given at that

time. It must l)e reeiiiphasized, however, that

during the 1977 epidemic preschool children appeared to be well protected. One must raise the question, therefore, as to whether the prob-lem or problems that existed at the time the 10- to 14-year-old group was immunized stopped being a probleni five years ago.’ In comparing

hemag-glutinatioii inhibition titers of vaccines, Yeager et

al.’ reported a higher failure rate in 1 1-, 12-, 13-, or 14-month old children immunized between

1969 and 1976 than in those immunized since that

time. They found, moreover, that the measles antibody titer in cord ser#{227}of children in 1976 was

approximately half of what it was in 1969 to 1970.

They suggest that higher maternal antibody titers in those earlier years may have persisted longer,

e.g., beyond the first birthday. The presence of

maternal antibody in these infants may have neutralized measles vaccine virus and prevented successful immunization of babies during this

earlier period. If this is indeed the case, the

change in recommended date for immunization

from 12 to 15 months at this time may be

irrational and perhaps counterproductive.

In delaying immtinization to 15 months, it is expected that a gain in the nuniber of infants

successfully immunized will more than offset the effects of postponement. The AAP Committee on

Standards of Child Health Care does not, at the

present time, recommend a scheduled visit to the pediatrician at 15 months of age. If parents are less likely to bring their children back for health care during the second year of life than during the

first, fewer children may be immunized. Because measles vaccine is usually given in combination with rubella and mumps vaccines, a number of

children may be unprotected not only against

measles but niumps and rubella as well. This

would be of particular concern among those groups who have a record of poor compliance. In 1975, when immunization was recommended at

the first birthday, it was estimated that only 53.9% of nonwhite children and 68% of white children ages 1 to 4 had received measles vaccine.

Rather than return at 15 months of age, chil-dren may l)e brought for immunization at 18

months of age. If an epidemic should occur, the very vulnerable young group would I)e

unpro-tected. During the 1977 epideinic in San Antonio,

Texas, a substantial number of the cases of

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1040 MEASLES IMMUNIZATION

measles in unininuinized individuals occurred in

this very young age group. Although the new

recommendations state that “in the face of a measles outl)reak, infants at risk of exposure may

he imnmnized as early as 6 months,” there were

no guidelines to define whether or not there was an outbreak. As there was great geographic

van-ation in the incidence of measles, each

communi-ty had to decide on its own whether to implement the recommendation to immunize at 6 months. The lack of guidelines resulted in a delay in

implementation with increased morbidity in the very young. In the case of polio, it was deemed

that two cases of the same senotpe within a 30-day period constitute sufficient evidence to

insti tute coii munity ml niunization programs. Similar guidelines are required for measles.

In trying to assess the advantage of changing

the immunization date from 12 to 15 months, we must be able to quantitate the advantage of such a change. Statistical difference assures us of the reliability of our data. They do not provide us

with the numerical difference which must be

weighed against the disadvantages of delaying

immunization to 15 months. The Red Book

Committee obviously considered the quantitative factor in making the additional recommendation

that

children whose live measles vaccine was given at or shortly after 12 months but before 15 months (during an epidemic) need not be recalled for immunization. However, such children should not be denied vaccine if they are brought for

this purpose to a physicians office or other health facility.

The assessment of vaccine efficacy must be based on what actually happens to children when

they are exposed to measles rather than solely on

serologic testing. Laboratory tests merely provide a guide for what one might expect in a clinical

situation. Indeed, Shasby et al. report that “at-j though the prevalence of detectable antibody in

children vaccinated at 13 months is greater than that in those vaccinated at 12 months, the difference was not quite significant in the attack

rates between these groups.” ‘ What is even more impressive is the failure of Marks et al.7 to find clinically significant differences between attack rates in children immunized at 12, 13, 14, or 15 months. Yeager et at. have-been careful to identify the variables of the hemagglutination inhibition test within their laboratory that may affect

results. Undoubtedly, some of the differences

between investigators reflect differences in sero-logic testing between laboratories. It is clear, moreover, that more recent investigations have failed to confirm that greater seroconversion rates are achieved when children receive measles

vaccine at 15 rather than 12 months of age.8-9

It is important to put things in perspective with

respect to measles vaccine. We now talk of cases in terms of tens rather than hundred thousands of

cases per annum and deaths in dozens rather than hundreds per annum. The attack rate for children aged 1 to 4 was 35/

100,000

in 1977, an epidemic

year, compared to 3,380/ 100,000 in the years 1960 to 1964 prior to measles vaccine. In the 10-to 14-year-old group, about whom we are most

concerned, the attack rates during comparable periods are 845 and 105, respectively. We still

must address the problem of high school- and college-age youths and military recruits. Several possibilities must be explored, including the option to permit nature to take its course, i.e., permit the pool of susceptible subjects to become exhausted by natural infection. It has been

suggested that serologic screening be carried out but there is no simple, inexpensive way for mass screening by hemagglutination inhibition at the present time. We are all aware of the inaccuracy of relying on history of illness or immunization to determine the need for immunization. The

suggestion that immunization routinely be given twice, once during and once after infancy, also must be examined.

The continuing presence of measles as a prob-tern 15 years after the introduction of vaccine

causes us to focus on some of the unanswered questions. Where, for instance, is the virus

between epidemics? Neutralization of vaccine

virus by passively acquired maternal antibody

cannot explain all of the vaccine failures early in the second year of life.8 Is there still something we do not hilly comprehend about the relative

inabil-ity of children of this age to respond to measles or

bacterial polysaccharide antigens? Most

impor-tant, how are we to achieve greater compliance

with immunization programs?

The enforcement of laws that require measles

immunization for school attendance has clearly

had an impact on reducing measles incidence.0

Hopefully, the increased use of television to

encourage immunization of younger children will also be effective. If we are to achieve our goal of reducing morbidity produced by natural infection and eradicating disease, advances in administer-ing vaccines must keep pace with our ability to develop these products.

PHILIP A. BRUNELL, M.D.

Department of Pediatrics,

The University of Texas Health Science Center

7703 Floyd Curl Drive

San Antonio, TX 78284

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PEDIATRICS

Vol. 62 No. 6

December 1978 1041 REFERENCES

1. Committee on Infectious Diseases: Measles- Vaccine

Recommendations-. Evanston, Ill, American Acade-my of Pediatrics, June 1977.

2. Measles-United States, 1977-1978. Morbidity Mortality Weekly Rep 27:235, July 14, 1978.

:3. Shelton JD, Jacobson JF, Orenstein WA, Schulz KF:

Measles vaccine efficacy: The influence of age at vaccination versus duration of time since

vaccina-tion.Pediatrics 62:961, 1978.

4. Shasby DM, Shope TC, Downs H, et al: Epidemic measles in a highly vaccinated population. N Engl I Med 296:585, 1977.

5. Yeager AS, Davis JH, Ross LA, et al: Measles immuni-zation: Successes and failures. JAMA 237:347, 1977.

6. Measles Surveillance, Report No. 10, 1973-1976. Atlan-ta, Center for Disease Control, 1977, p 16. 7. Marks JS, Halpin TJ, Orenstein WA: measles vaccine

efficacy in children previously vaccinated at 12 months of age. Pediatrics 62:955, 1978.

8. Wilkins J, Wehrle PF: Evidence for reinstatement of infants 12 to 14 months of age into routine measles

immunization programs. Am I Dis Child 132:164, 1978.

9. Reynolds DW, Stagno 5, Herrman KL, et al: Antibody

response to live virus vaccines in congenital and

neonatal cytomegalovinis infections. I Pediatr 92:738, 1978.

10. Measles and school immunization requirements-United States, 1978. Morbidity Mortality Weekly Rep 27:303, August 18, 1978.

Asthma

and

allergists:

A modern

perspective

In the current issue of Pediatrics (page 1061), Leffert elegantly reviews the theories of asthma pathogenesis, while identifying areas of our continued ignorance. He also calls for pediatri-cians to assume a more central role in the

management of this condition rather than resort

to the traditional, often near automatic practice of referring and deferring to allergists. It would be a pity to obscure the important theme of Leffert’s article by an intramural fight for “turf” between pediatricians and allergists.

The noteworthy points of Leffert’s article are: (1) Not all asthma is due to allergy. (2) Dramatic developments in asthma therapy have taken place in recent years. ‘ “ (3) Means for satisfactory control of asthma in the vast majority of asthmat-ics is at hand.

The long-standing assumption that all

asthmat-ics can be presumed to have a significant “allergic

component” has resulted in (1) a relative neglect

of the study of nonallergic asthma mechanisms;

(2) a relative lack of appreciation of the hetero-geneity of asthma or “the asthmas”5; (3) a relative

distraction from application of pharmacologic

therapy with understanding, precision, and meticulous attention to detail; and (4) a relative

overuse of allergy injection therapy for asthma in terms of both duration of therapy and numbers of patients who receive it.’

Pediatricians who believe that skepticism of allergists and their practices is evidence of critical

acumen should not be reassured by Leffert’s

message. It would be harmful to conclude that

allergy consultations for asthmatics are not neces-sary. If pediatricians were to continue to manage

asthma medically by the precepts taught in medi-cal schools and training programs just a few years ago, they would not be giving adequate care today. Pediatricians can and should assume a greater role in asthma management, but they can do so only if they are willing to (1) update their understanding of the mechanisms of asthma; (2) update their knowledge of the now more compli-cated pharmacologic treatment of asthma; (3) give up some old misconceptions concerning asthma; (4) devote the time necessary to teach the patient and/or parents what they need to know about the condition; (5) devote the time necessary to secure compliance with a chronic or intermit-tent medication program; and (6) devote the time

during follow-up to adjust and readjust the medi-cation program to the patient’s individual need and tolerance.

Pediatricians can further improve their service to asthmatics by understanding the proper role of the modern allergist. A modern allergist should be expected to contribute to an asthmatic’s care in

any or all of the following specific areas: (1) aid in

the diagnosis of asthma, not by skin testing but by

objective demonstration of reversibility of airway

obstruction; (2) provide objective assessment of control by means of serial pulmonary function

measurements; (3) determine whether a

signifi-cant allergic cause plays a role; (4) identify the predominant allergic cause if such is present; (5) define whether the predominant allergic cause is avoidable, and give specific, individualized advice (not the standard “dust control” handouts) for avoidance based on identification of specific cause; (6) refine pharmacologic management with

emphasis on reducing medication side effects and minimizing the use of steroids; (7) devote time to those patients whose severity of condition, personal attitudes, and prior misconceptions require extraordinary attention; (8) identify and manage underlying complications; (9) define

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1978;62;1038

Pediatrics

Philip A. Brunell