Press Briefing Transcript

CDC Telebriefing: Status of Serogroup B Meningitis Cases in the United States

Monday, November 25, 2013 at 2:00 E.T.

• Audio recording [MP3, 8.93 MB]

OPERATOR: The conference will begin momentarily.  You may press star 1 to ask a question.  Again, please stand by.  Today's call will begin momentarily.  Thank you. 

Welcome and thank you for standing by.  At this time we are in a listen-only mode.  During the question-and-answer session you may press star 1 to ask a question.  Today's conference is recorded.  You may begin. 

BARBARA REYNOLDS: Thank you, Shirley.  This is Barbara Reynolds from the CDC.  Welcome to our telebriefing on meningococcal disease this afternoon.  The speaker for this afternoon's telebriefing is Dr. Amanda Cohn—I’m going to spell that, c-o-h-n, four letters.  She's a pediatrician and an expert in meningococcal disease here at CDC.  I think what we'd like to cover today is some of the basics, and a brief update about what's been happening over the last couple of weeks around meningococcal disease, in both New Jersey and in California.  And then make sure that everybody understands what we believe is important to know as we plan for our holidays and make those travel connections.  Amanda? 

AMANDA COHN: Good afternoon.  So, I’m going to give a basic overview of meningococcal disease, and provide you with some facts which can help families and providers understand and be aware of potential of meningococcal disease of students traveling home for the holidays.  Meningococcal disease can be devastating and can strike otherwise healthy individuals.  Every case of meningococcal disease really causes increased concern.  But outbreaks cause an especially high amount of anxiety.  And, I know there's quite a bit of anxiety related to these two outbreaks of meningococcal disease that we're seeing right now at Princeton and UC Santa Barbara.  Fortunately, there haven't been any fatalities from these two outbreaks, but there have been some very serious cases.  Both universities are experiencing cases of serogroup B meningococcal disease.  And this is the strain for which there is no current vaccine that’s licensed in the United States to prevent.  Our universities—many universities have very high coverage with the licensed and recommended vaccine that protects against serogroup C and Y. So we started to see fewer cases of serogroup C and Y meningococcal disease and more cases of serogroup B disease.

 Meningococcal disease is caused by the bacteria neisseria meningitidis and it’s also sometimes called meningococcus.  Fewer than 1,000 cases now occur each year in the United States.  In 2012, about 500 cases were reported, and cases occur in all age groups.  Reports of this disease is more common in the winter months.  Typically almost all cases of meningococcal disease are sporadic.  Very few cases occur as part of our -- as part of an outbreak in terms of the total number of cases we see in the United States.  But we do see a couple of meningococcal disease outbreaks typically every year.  In the late 1990s, and early 2000s, we had close to 3,000 cases of meningococcal disease a year, so we actually have drastically fewer cases of meningococcal disease than we have in prior years.  There are two serious forms of meningococcal disease—meningitisand septicemia. Meningitis is an infection of the protective membranes covering the brain and spinal cord, which is known as the meninges.  Septicemia is an infection of the blood stream, and septicemia causes bleeding in the skin and organs and is often when we see complications from meningococcal disease that are not neurologic, it's frequently caused by septicemia.

So even with antibiotic treatment, people die in about 10 to 15 percent of cases of meningococcal disease.  About 15 percent of survivors have long term disabilities such as loss of limbs, deafness, nervous system problems, or brain damage.  Early recognition and early treatment of meningococcal disease is key to reduce the long-term sequelae.  However, it's often difficult to diagnose meningococcal disease because often the first signs and symptoms are similar to the flu.  Vaccination is the best way to prevent meningococcal disease when it's a vaccine preventable strain.  Hand washing and covering your coughs or sneezes is also a good practice to follow.  It's critical everybody be aware of the signs and symptoms of meningococcal disease and to seek treatment immediately.  So those signs and symptoms of meningococcal disease include rapid onset of high fever, headache, and stiff neck.  And when we say headache, we mean it's among the worst headaches that somebody's had in their life.  And with the stiff neck, they really can't move their neck, or they can't, for example, touch their chin to their neck.  Towards their chest, excuse me.  Other symptoms include nausea, vomiting, increased sensitivity to light, confusion, exhaustion, and sometimes a rash.

Fortunately, meningococcal bacteria are harder to spread than viruses than things that cause things like the flu or respiratory viruses, and they don't live long outside the body.  They're spread through the exchange of respiratory secretions.  So spread of the organisms happen through close contact, such as household contact or French kissing.  For example, if roommates who spend a lot of time together, are potential close contacts of a case of meningococcal disease.  These bacteria are not spread by casual contact like being in the same room with somebody who is sick or carrying the bacteria or handling items that they touched.  At any given time, about 10 percent of people, not just in outbreaks, but all over in the United States, carry these bacteria in the back of their nose or throat and don't ever develop symptoms.  This is known as carriage or being a carrier.  These rates are often lower when it comes to looking at the strain that’s causing an outbreak.  Often you only see less than 5 percent carriage of that strain in a population where the outbreak occurs.  Once a person becomes a carrier, most people develop immunity and the bacteria disappear from their nose and throat and then they're no longer a carrier.  But rarely, the bacteria invades the blood stream and this is what happens when a person develops the disease. Since the bacteria can spread through carriage, most cases of meningococcal disease appear to be random and aren't directly linked to each other.  Even in the case of an outbreak—the cases are not occurring among close contact with each other, it's happening in an organization or community. 

There are several serogroups or strains of these bacteria.  The most common one circulating in the United States are serogroups B, C and Y.  In the U.S., we have approved vaccines to help protect against serogroup C and Y, which are still seen in the U.S. although to a lower extent than they were prior to the vaccines being used. And serogroups A and W which occur globally.  These are vaccine are recommended for all adolescents with the first dose preferably given at 11 to 12 years old, and a second dose at 16.  We don't have a vaccine in the U.S. licensed to protect against serogroup B, which is the cause of the cases at Princeton University and UC Santa Barbara.  And that's because there's been challenges making of serogroup B vaccine, because the target serogroup capsule looks like an antigen we actually have in our bodies and so it’s not immunogenic. So we have to find other targets for vaccination. As more adolescents become vaccinated, we've seen fewer serogroup C and Y outbreaks in this age group.  Every case of meningococcal disease requires a public health response by local and state health officials.  Now I’ll talk a little about prevention and outbreak control. 

Health officials follow up with a patient to see if they've come into close contact and then they recommend preventive antibiotics to close contacts.  Cases are reported quickly, meningococcal disease is highly recognized, and reported to health departments.  We hear about almost all of the cases that occur in the United States.  All of these public health partners work together to prevent additional cases.  It's really close contacts of cases that are at especially high risk of developing disease immediately after a case occurs.  And that's why we offer antibiotic chemoprophylaxis for those contacts.  One of the cases we don't see the cases occur in those close contacts because health departments do such a good job of their chemoprophylaxis around these cases.

 In general, CDC defines an outbreak of meningococcal disease of three or more cases in three months that can't be connected to each other.  And these outbreaks occur in a certain population, like school or organizations.  Most outbreaks of this disease are self-limited and no more than three or four cases occur.  However, when cases continue to occur over several-month period, like what is happening at Princeton University, intervention is required to reduce the length of the outbreak.  In an outbreak caused by serogroup C or Y meningococcal disease, we would recommend the quadrivalent meningococcal vaccine to prevent additional cases.  Until very recently, there was no available and broadly effective serogroup B vaccine that could be used to help an outbreak in the United States.  However, there's now a vaccine that was recently licensed for use in Europe and Australia, but not in the United States.  The CDC and the Food and Drug Administration have determined that the unique pattern of disease in this Princeton outbreak, the high rate of cases that have occurred and over the long period of time they've occurred in warrants access to this serogroup B vaccine for that high-risk population.  Each outbreak is unique and requires a rigorous assessment before use of this vaccine can be considered.  With that said, we're open to recommending this vaccine during other outbreaks of serogroup B meningococcal disease and will take each outbreak – and we’ll follow each outbreak very closely, and make decisions about requesting use of vaccine for additional outbreaks when needed. 

Partners are working hard to organize potential serogroup B vaccine campaigns at Princeton University as quickly as possible.  Expanding access for use of an investigational vaccine such as this requires careful review of the particular circumstances of the outbreak and making sure the vaccine can be safely administered and ensuring the appropriate systems are in place for safety follow-up after the vaccination campaign.  Importing vaccine that’s not approved in the U.S. even when licensed is a complex process that takes time.  There's all sorts of things that go into it, including getting approval from agencies, and the university.  We have to have special labeling, and it has to be sent from Europe, and the climate has to be controlled.  So there's all sorts of quality things that are happening to make sure that the vaccine arrives and can be used safely and effectively.  All involved anticipate that the vaccine will begin once everything is in place, shortly after the Thanksgiving holiday hopefully.  CDC is continuing to work with local and state partners to closely monitor the UC Santa Barbara situation, and if cases continue to occur, we'll determine the best course of action.

 In the meantime, what we want to stress today is the importance of knowing the signs and symptoms of meningococcal disease and the need to seek prompt care if concerned.  If anyone is connected to either of the universities develops a fever, headache or rash, he or she should seek medical attention.  But we also want to make sure that there is an understanding that there's no need to really change family members and communities' contact with students from these universities as they're traveling home for the Thanksgiving holiday.  CDC does not remember curtailing social interactions or canceling travel plans as a preventive measure to prevent cases of meningococcal disease.  Instead, we really just want focus on reminding that students in the -- students from these universities remain vigilant to the symptoms of meningococcal disease, seek treatment and that providers are aware of the situation. Therefore, we are sending out a health alert to providers and state and local health departments, which will hopefully increase awareness for providers to consider meningococcal disease in their differential diagnosis, if a student presents with symptoms from one of these two universities.  Thank you. 

BARBARA REYNOLDS: Okay.  Thank you, Dr. Cohn.  Shirley, I think we're ready to open up for questions. 

OPERATOR:  We now begin the question-and-answer session.  If you would like to ask a question, please press star 1 and record your name clearly.  To withdraw your request, you may press star 2.  Star 1 to ask a question.  One moment for our first question.  Our first one comes from Miriam Falco from CNN Medical News.  You may ask your question. 

MIRIAM FALCO: Thanks for taking the questions.  I have two points of clarification.  Number one, you said the most common strains in the U.S. are B, C and Y.  But that makes it to me sound like B is very common.  I thought B was rare in this country.  The second question is you described an outbreak as three or more cases that are unrelated.  But weren't the three cases in -- at UC Santa Barbara connected?  So why is that an outbreak? 

AMANDA COHN: Hi.  So to clarify the occurrence of serogroups, I think meningococcal disease, there's only about 500 cases of meningococcal disease that occur in the United States as a whole.  So B, C and Y account for about a third of cases.  Though I believe in 2012, we had about 160 cases of serogroup B meningococcal disease.  I think to clarify out -- it used to be rare, and much more common for serogroup B to occur.  In the setting of such high vaccine coverage, which is great, we're actually not seeing very many serogroup C outbreaks on college campuses.  We're seeing more of the serogroup B outbreaks.  They're not occurring more frequently, but it's the lack of serogroup C outbreaks that's making them more prominent.  To answer your second question about the cases at UC Santa Barbara.  I can let the public health departments answer more specific details about those cases.  When we say they can't be linked, it's directly linked.  If a roommate of a case develops a disease, that's direction relation.  If it's linked indirectly like through this person knew this person who knew this person, that's not considered a direct linkage. 

BARBARA REYNOLDS:  Okay, next question, please? 

OPERATOR:  The next question comes from Mike Stobbe from Associated Press.  You may ask your question. 

MIKE STOBBE:  Hi.  Thank you for taking my question.  I have a couple, actually.  Dr. Cohn, I think you said coverage rate was good among the students at Princeton and UC Santa Barbara.  Do you have a statistic what proportion of the students there were vaccinated?  I understand it's against C and Y.  I was also wondering in the case of Princeton, where the vaccine is being imported, do you know how many doses and how much money that will cost and who's paying for it?  And I’m sorry, if I could throw a third one in.  Do you have any update; are there plans to license the B vaccine in the U.S.?  What's going on that front? 

AMANDA COHN:  Can you repeat the last question?  I'm sorry. 

MIKE STOBBE: Yeah.  You all have said that the serogroup B vaccine is licensed in Europe and Australia, but not here.  Are there -- why isn't it licensed here?  Are there plans to license it?  What's going on in that front? 

AMANDA COHN: Okay.  For your first question, I would prefer to give exact coverage -- for you to go the health departments in New Jersey and California for the exact coverage rates.  I can tell you at least at Princeton University, coverage is incredibly high, and very few people on that campus are not vaccinated.  Especially, I think, in the undergraduate population living on campus.  Your second question regarding logistics of the Princeton vaccination campaign.  Several different partners are working closely on all of those details, which i would prefer not to go into specifically on this call.  We can get back to you with some of those details.  But i think as agreements are getting in place, some of that information will become more available.  And to answer your third question about licensure of serogroup B vaccine. The reason this vaccine is not licensed in the United States is because the company made a decision, in part, due to the low incidence of meningococcal B disease in the United States right now, to move forward with licensure, with a vaccine that includes serogroups A, C, Y and W and B.  They're combining their currently licensed meningococcal vaccine with one that is licensed in Europe.  So they're starting sort of -- the process will take longer.  There is another product under development that is a stand-alone serogroup B vaccine that is in late stage development in the United States from a different company. 

BARBARA REYNOLDS: Okay.  Next question, please? 

OPERATOR: Thank you.  The next question comes from Maggie Fox with NBC News.  You may ask your question. 

MAGGIE FOX:  I'm trying to wonder how to explain to a lay audience the different between a strain and a  serogroup.  They're used in varying ways in these reports.  Serogroup is a jargony term, and I’m wondering how best to explain it, again, to a lay audience.  Thanks. 

AMANDA COHN: That's a great question.  Serogroup is definitely a scientific word to describe the type of capsule around the meningococcal.  You can use the word strain when we describe different serogroups.  The word strain would be the b strain or c strain.  When we're talking about whether or not strains are linked to each other, there we do additional molecular testing which looks at more than the capsule to see if the strains are the same.  For example, we know that the strains that have caused all of the cases in -- at Princeton are identical.  That's what helps us understand if an outbreak is being caused by one strain.  And that doesn't necessarily mean you could have the same serogroup, but the strains could look a little different.  Does that help? 

MAGGIE FOX: Well, a little bit.  Is there another way we can use for the second use of strain?  Because I’d like to talk about the B strain as opposed to the B serogroup.  But then when you talk about, when you do the genetic typing --

AMANDA COHN: I think we don't like to use the word clone, we don’t like to use the word clone, but it's a -- you could say --

MAGGIE FOX: How about genetic fingerprints? 

AMANDA COHN: Yes, the same genetic fingerprint would be a great way to describe it.  Thank you. 

MAGGIE FOX: Thank you. 

BARBARA REYNOLDS: Thank you.  Next question, please? 

OPERATOR: Next question comes from Dan Childs with ABC news.  You may ask your question. 

DAN CHILDS: Thank you very much for taking my question.  Actually I have a two-part question.  Given the decision that was made to distribute this vaccine at Princeton, how unprecedented is this move, and will we be seeing it happen more?  And the second part of the question is, given that this stuff is being taken, what might it mean if anything for the approval of the vaccine in the U.S.? 

AMANDA COHN: I think that this is -- I can't respond that this is unprecedented, never happened before in the United States, but certainly in the amount of time, in the ten years I’ve been working at CDC, and certainly for meningococcal disease, we have never had expanded use of an unlicensed vaccine product for use to prevent cases in an outbreak.  So this is highly unusual.  I'm not sure if it's completely unprecedented.  But I think it speaks to the really very high attack rates that we saw at Princeton University, and how strongly we felt along with our partners in New Jersey and at Princeton that we needed to do something to prevent additional cases.  I also think that now that this product is licensed in a different country, I think that made the path toward expanding access to this vaccine easier than in the past, in licensure in other countries.  There have been a couple of situations where there were smaller scales of outbreaks at universities, that haven't reached this level.  But because the vaccine wasn't licensed in a different country, it didn't seem likely that we would be able to use it.  The second part of your question is what will this do to licensure of this product.  I think i don't have a good answer for you for that.  As I said before, this company is going towards licensure for a different product.  But I think really FDA would be the best person to answer questions related to regulatory -- questions related to future licensure vaccines. 

DAN CHILDS: Thank you. 

OPERATOR: The next question comes from Curtis Skinner from Thomson Reuters.  You may ask your question. 

CURTIS SKINNER: Hi, I just had a quick question.  I understand that the CDC has recommended the use.  But I understood that the final approval is still pending.  Has that been made?  Do you have a time frame when that will be made? 

AMANDA COHN: We have--there are multiple agreements and approvals that are readily being put into place as we speak.  I can't give you an exact date.  But we expect approval to occur in time to be able to provide the vaccine as soon as possible. 

BARBARA REYNOLDS: Next question, please? 

OPERATOR:  Next question comes from Charles Min with The Daily Princetonian.

CHARLES MIN:  Two-part question.  First, the CDC only recommended the vaccines for undergraduates and faculty with certain health circumstances.  So why is the majority of faculty and staff excluded from the list of those who can receive a vaccine?  And is it basically a good idea for only students to be vaccinated? 

AMANDA COHN: Is it only a good idea for who? 

CHARLES MIN: It was only recommended for undergraduates, graduates and faculty with certain health conditions.  So why is the majority of the faculty excluded from the list of those who can receive the vaccine? 

AMANDA COHN: All of the cases that have occurred at Princeton University have occurred among undergraduates living on campus.  And so the vaccine, we want to target the vaccine campaigns to the people who are at highest risk.  And that appears to be the group that would get the most benefit.  If we--I think we have to balance the risks and benefits of using an unlicensed vaccine product.  And so most outbreaks of disease that occur on college campuses, there's very -- I can't think of any examples where there's been a case that did not occur as an undergraduate student. 

BARBARA REYNOLDS: Thank you.  Next question, please? 

OPERATOR:  The next question comes from Betsy McKay with the Wall Street Journal, you may ask your question. 

BETSY MCKAY: Hi, thank you very much.  I wondered if you could step back a minute and talk about the rates this year versus previous years again.  How many more – I mean, it seems unusual that there are two outbreaks, right?  And so how many more cases of serogroup B meningococcal disease are there than usual this year?  Is this an unusual year?  And if so, why -- what's going on?  And are there more -- are there more outbreaks that we're not aware of on campuses or elsewhere? 

AMANDA COHN:  These two outbreaks occurring at the same time is unusual.  We frequently -- we don't usually have two outbreaks happening, especially on different coasts at the same time.  But I will say that our meningococcal disease, the number of cases that have been reported to the CDC at this time is the same as last year.  So we're not seeing overall increases in the number of serogroup B cases reported in the United States.  And after working on this for so many years, I really -- health departments are incredibly good at finding and identifying meningococcal disease cases and identifying clusters, or outbreaks and responding to them early and rapidly.  And so I really do feel confident that these two outbreaks are the only ones that are occurring at this time.  And the health departments work with CDC very closely on making sure that outbreaks are identified early. 

BETSY MCKAY: Are they related? Can I ask a quick follow-up question?  Is there any way that the two campus outbreaks, even though they're thousands of miles apart, are related in any way? 

AMANDA COHN: The strains -- so we do not believe that the two outbreaks are related in any way.  And we have done some molecular finger printing—some genetic finger printing— that indicate the strains that are causing the two outbreaks are different. 

BETSY MCKAY: Thank you. 

BARBARA REYNOLDS: The next question, please? 

OPERATOR: Next question comes from Jane Derenowski with NBC network news.  You may ask your question. 

JANE DERENOWSKI: Good afternoon.  I have two questions.  Was the most recent case at Princeton reported on Friday classified as type B? 

AMANDA COHN:  We don't have that information at the time.  And I would suggest contacting your local health department.  The health department in New Jersey for that information. 

JANE DERENOWSKI: And my second question was, somewhere in this telebriefing, you talked about prophylactic antibiotics for any suspected cases.  Would that extend to people who live or interact with people who are suspected of having this? 

AMANDA COHN:   So, health departments do close follow-up and do an investigation around each case of meningococcal disease, to identify all potential people who were in close contact with that case who may have been exposed.  And that includes household members, people who were working very close with that person, in a way they would have been potentially sharing respiratory secretions, like roommates, sometimes teammates who are traveling together.  But it really is people who are in close contact with the case.  And doesn't include, for example, everybody working in an office with that person, or people they may have interacted with.  So, health departments frequently start those investigations prior to a case becoming confirmed.  So when we say suspect, we usually call those cases probable cases.  So it looks very likely that that person does have meningococcal disease. But because you want to get those chemoprophylactic antibiotics in those close contacts immediately, the case is not always confirmed.  But that's true for the cases in these outbreaks and all cases reported in the U.S.  Investigations are done around all cases of probable meningococcal disease. 

BARBARA REYNOLDS: Thank you.  Next question, please? 

OPERATOR: Next question comes from Anemona Hartocollis with The New York Times. You may ask your question. 

ANEMONA HARTOCOLLIS: Hi.  Thank you.  I just wanted to go back to the Thanksgiving travel advisory.  You're saying that people shouldn't curtail their plans.  But why aren't you worried that the disease would become spread more widely outside of the Princeton and Santa Barbara communities, and second, do you have any specific advice for families at Thanksgiving?  Should they keep the number of guests down?  Should they disinvite babies and grandma?  Should they change their table behavior, something like that? 

AMANDA COHN:  You know, I really totally understand the anxiety and concern that cases cause.  It doesn't seem satisfactory for us to say, don't -- we don't mean to say don't worry about it.  But we really don't have evidence, and in past outbreaks there hasn't been spread to the community.  Cases really do occur in this university setting where there's probably a very specific pattern of transmission among college students.  So we really don't have evidence to suggest that kids going home for Thanksgiving will be spreading the strain into those communities.  Now, if a case -- if a student does develop disease over the Thanksgiving holiday, then those family members and close contacts would definitely be given preventive antibiotics.  But while it's not completely satisfying, we don't have any evidence to say that curtailing activities or having fewer people at the table really helps prevent spread of the disease.  If anything, it's just sorting reminding people to use good normal hygiene practices, such as washing your hands and coughing and sneezing into your arm.  And sort of having increased awareness for good hygiene practices. 

ANEMONA HARTOCOLLIS: Thank you. 

BARBARA REYNOLDS: Thank you.  Next question, please? 

OPERATOR: Next question comes from Veronica Griffin from CBS Atlanta news. 

VERONICA GRIFFIN: Hi, just want to get clarification on the number of cases, please? 

AMANDA COHN:  Are you asking about the number of cases that have occurred during the outbreaks or in the United States? 

VERONICA GRIFFIN: Sorry, during the current outbreaks. 

AMANDA COHN:  There have been seven confirmed serogroup B cases at Princeton University, and one additional case in which additional testing is being conducted right now.  And there are three cases at UC Santa Barbara. 

VERONICA GRIFFIN: Thank you. 

BARBARA REYNOLDS: Thank you.  We have time for just a couple of more questions.  Next question, please? 

OPERATOR: Next question comes from Michael Smith with MedPage Tech Today.  You may ask your question. 

MICHAEL SMITH: Good afternoon, Dr. Cohn.  I'm a bit puzzled by the notion of outbreak in this case.  It seems to me what you're saying is this stuff doesn't spread easily, except among close contacts.  And yet you define an outbreak as a number of cases in which there's no epidemiological link.  I don’t know how the disease spreads in that case.  I wonder if you could comment on that a little bit. 

AMANDA COHN:  It’s very challenging.  And we -- it's -- meningococcal disease is always perplexing.  But I think that spread is through close contacts.  But what happens is, people carry the organism, but most people who carry the organism in their throats don't become cases.  So there's carriage from one person to another.  Really, the definition of an outbreak is sustained transmission of the organism in an organizational setting or in a community.  And so it's really those cases that aren't linked to each other.  And that allow it to be concerns that there's transmission going on between carriers.  Those cases are just 1 in 100 or 1 in 1,000 people who actually carry the organism in their throats.  We don't have a good sense of what that actual number is.  But more people are carriers than there are actually cases.  I see what your question is, why are we not then worried about it spreading into the community.  We don't have a good -- we don't have a great understanding of the organism and how it spreads.  But what we do understand is that outbreaks really haven’t spread from universities into communities in the past.  There have been community outbreaks of meningococcal disease.  But we haven't seen cases occurring in universities expanding into those communities. 

MICHAEL SMITH: Just one follow-up, if I may.  You said the attack rates are very high in Princeton.  The eight cases it strikes me are over something like an eight or nine-month period.  What would the -- if that's a high attack rate among that student group, which is I don't think is very large, what would be an attack rate normally?  I'm just trying to get a sense of what you meant by high attack rate. 

AMANDA COHN:  So in most of our outbreaks, we see about three or four cases occur in a couple of month period of time and then we don't see additional cases.  Depending on the size of the college or organization in which the outbreak is occurring, those attack rates usually range anywhere from 10 to 20 per 100,000.  So one to two cases per 1,000 people at the university.  If you expand that, and you look at Princeton university and the size of the university, we have an attack rate of over 100 per 100,000 or over 10 cases per -- sorry, or almost one case per 1,000 people -- I may have said that wrong. 

MICHAEL SMITH: Thank you very much. 

BARBARA REYNOLDS: Thank you.  Next question, please? 

OPERATOR: Thank you.  Next question comes from Lisa Schnirring from CIDRAP News.  You may ask your question. 

LISA SCHNIRRING: Hi.  Thanks for your availability today.  I understand the part about having providers kind of look for students who might get sick when they're home from school, or whatnot.  I was just wondering what the incubation period is for that type of infection? 

AMANDA COHN:  So, typically we say that the incubation period for meningococcal disease is about one to seven days, with most cases actually occurring a couple of days after exposure.  So that's our typical response.  I have to say that we don't have as much information about incubation periods for serogroup B disease, most of our data is based on serogroup C disease, but we would expect it to be similar. 

LISA SCHNIRRING: Thank you. 

BABARA REYNOLDS: Thank you. One more question, please? 

OPERATOR: Next question comes from Robert Lowes from Medscape Medical News. You may ask your question.

ROBERT LOWES: Thanks for taking my question.  The final decision by the CDC to allow the vaccination under sort of limited circumstances, what does that hinge on? Why hasn't it been made yet? 

AMANDA COHN: What do you mean why it hasn't been made yet?  For which situation? 

ROBERT LOWES: for Princeton, you haven't made it yet.  What does the final decision to approve the use of this vaccine, what does that hinge on?  What do you have to decide? 

AMANDA COHN: The investigational review board at CDC is reviewing the protocol.  And basically, just making sure this is a group that, in short, that we're doing everything as safely and effectively and making sure that -- for example, the consent forms and that the kids we’re getting vaccinated fully understand the vaccine, and that it’s an investigational vaccine. It's actually just a lot of materials for this group to go through.  And so we expect that we will receive approval once we've sort of met all of the requests of this review board that's really looking out for human subjects, and making sure that the participants who are getting the vaccine are -- it's being -- the campaign is being done safely and effectively. 

ROBERT LOWES: Okay. Thank you. 

BARBARA REYNOLDS: Okay, good. One last question, please. 

OPERATOR: Next question comes from Mark Bernstein with Princeton Alumni Weekly. You may ask your question. 

MARK BERNSTEIN: Doctor, just a two-part question.  First is, does the CDC have any idea how this outbreak at Princeton began? Where did it actually come from? The other part is, are there any particular questions that parents of students should be asking before deciding whether or not their children should get the vaccine, if they're eligible for it? 

AMANDA COHN: The first answer to your question, unfortunately we have no idea why this outbreak is occurring at Princeton University at this time. And I think it's always difficult to understand why outbreaks happen. Very rarely can we ever identify -- it's not like there's a point source or anything we can identify.  Your second question, did you ask about what parents can do to make sure that -- to make the decision about --

ROBERT LOWES: Yes. Are there things that they should be asking themselves or asking health officials before deciding if their children should get the vaccine? 

AMANDA COHN: I think that Princeton University and the New Jersey Department of Health are doing quite a lot to educate parents and students prior to the vaccination campaigns occur.  They're working on all those materials.  And I think parents will be well informed to make the decision.  But we also have on our website, on our CDC website at www.cdc.gov/meningococcal, there's a box that has specific list of questions and answers regarding the Serogroup B outbreak that answers questions about vaccinations. 

ROBERT LOWES: Thank you. 

BARBARA REYNOLDS: Okay. Thank you. I think that ends perfectly, Dr. Cohn. If you have any other questions or would like some additional information on this subject, you can reach out to our CDC media relations office at 404-639-3286. And thank you, Shirley. This ends the telebriefing. 

OPERATOR: Thank you. This does conclude today's conference. We thank you for your participation. At this time you may disconnect your lines.

###
U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES