Revisiting meningococcal vaccine for school

August 2001

---Philip A. Brunell, MD

There has been a change in the epidemiology of meningococcal disease, which has resulted in increased attention to preventing infection. During the 1998-99 academic year, there were 88 cases with 8 deaths among college students. There also has been an increase in vaccine-preventable strains responsible for these cases (Clin Infect Dis. 2000;30:648). This has led to a re-evaluation of the need to immunize college students. Recommendations were published by CDC (MMWR. 2000; 49(RR07):1-10), the Red Book Committee (Pediatrics. 2000;106: 1500) and the American College Health Association.

As students depart for college campuses, undoubtedly some questions will arise about the advisability of immunization against meningococcal disease. Some colleges have mandated immunization. Parents may ask about immunization of high school students, as there also have been reports of cases in this population. Indeed, they may ask about other members of the family.

Red Book recommendations

The recommendations in the Red Book are quite explicit. They emphasize vaccinating freshman who are living in dormitories, as they are at greatest risk. The recommendations indicate that students should be informed about meningococcal immunizations — not that immunization should be considered routine. They state that upper classmen and graduate students living in dormitories or health care workers providing care for these individuals also may choose to be immunized. They further state that reimmunization should be considered for entering freshman who were immunized 3 to 5 years prior and who will be living in dormitories.

Those who will be travelling to areas where there is a high risk of exposure to disease should be reimmunized if this interval has elapsed since their last immunization. Frequent reimmunization does not appear to be needed and may produce some immune tolerance.

The Red Book does not recommend immunization of students not living in dormitories as they do not appear to be at any greater risk that non-college students. However, if it is requested, the request should not be refused. In studies conducted in Maryland and studies done by CDC, 72% and 56% of cases occurred in non-first year students. In the Maryland study, most of the cases in 17-year-olds were in high school students. Thus, we get into the “numbers game.” If we want to get the maximum “bang for the buck,” we go for college students living in dorms who have the highest rate. If we want to stamp out all preventable disease we immunize everyone. The latter I might add is not practical nor recommended at this time. Therefore, we have a rather permissive recommendation. To paraphrase the CDC recommendation, those who provide medical care to freshman dormitory residents should give information to students and their parents about meningococcal disease and the benefits of vaccination. Other undergraduate students wishing to reduce their risk can also choose to be vaccinated.

Why is the recommendation for freshmen living in dormitories so permissive? Again, numbers. It is estimated that the number of cases of meningococcal disease annually is about 2,300. Only a fraction of these are college freshmen living in dorms. Thus, in a CDC surveillance survey, “88 cases of meningococcal infection that resulted in 8 deaths were identified among college students.” We do not know the completeness of this surveillance or how many of these were freshman living in dorms. In the Maryland study (JAMA. 1999;281:1906), many of the cases did not fall into this category. Thus, one would have to immunize millions of freshman living in dorms to prevent some of these cases. It should also be noted that the vaccine is not perfect and that the group B serotype is not covered by the vaccine. Although, in recent years most of the cases in this age group were caused by groups included in the available tetravalent vaccine. Group C strains, which have the greatest fatality rate, are on the rise in this age group. Therefore, we can go from “why take a chance?” to “what’s the big deal?”

Also, our current system of managing outbreaks is not satisfactory. We rely on rifampin prophylaxis and/or immunization. These are expensive and are put in place after there has been a case of meningococcal diseases. Most of the U.S. disease is endemic rather than occurring in epidemics. The solution is obviously universal immunization in infancy with an effective vaccine. The highest rate of disease is in infancy, at a time when current vaccines are not effective. However, efforts are being made to produce conjugate meningococcal vaccines. Such a vaccine for prevention of group C disease is given universally in England.

One of the major problems has been developing a vaccine against group B, which causes about one-third of the cases and a proportionally high rate in infancy. Although the number of cases is fewer than those caused by Haemophilus, the number of deaths is similar, as meningococcal infection is more likely to have a fatal outcome.