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One-shot Solution Explored for H1N1 Vaccine

September 11, 2009 at 12:00 AM EDT
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Margaret Warner speaks with Dr. Anthony Fauci of the National Institute of Allergy and Infectious Disease about a new H1N1 flu vaccine.

MARGARET WARNER: Since the swine flu outbreak began last spring and spread to more than 100 countries, there has been a race to create an effective vaccine. In the U.S., H1N1, as it’s called, infected more than a million people and caused about 600 deaths.

The flu threat diminished over the summer here, but it never went away, and now it’s returned for a new season. Already, it’s been detected in all 50 states and is widespread in the Southeast, plus Maryland, Oklahoma, Arizona, and Alaska.

Early on, the U.S. contracted to buy 195 million doses of the vaccine. Unknown at the time was: Would it be effective, would it be ready in time and in sufficient quantities?

Today, there was some good news on the vaccine front. Clinical trials show that just one dose will be effective for most adults who need it.

Dr. Anthony Fauci is head of the National Institute of Allergy and Infectious Diseases, which has overseen the government trials, and he joins us from the National Institutes of Health tonight.

And, Dr. Fauci, welcome. Thanks for joining us.

DR. ANTHONY FAUCI: It’s good to be here.

MARGARET WARNER: So how important is this news today, in terms of how well protected Americans will be from the H1N1?

More Americans can be protected

DR. ANTHONY FAUCI: Well, it really is very good news, Margaret, because when we first noticed this vaccine in April of this year and decided to go ahead as you would expect to try and make a vaccine, it was unclear whether a vaccine would even induce a response that would be protective and whether or not it would take more than one doses, two or more doses of a higher dose, because our previous experience with the H5N1 bird flu that we've been tracking for years was that the vaccine that we made required an exorbitantly high dose.

The results that we're hearing here today and that we presented today in Washington indicate that a single dose of the standard dose of what we give every year for seasonal flu induced a very potent response in a vast majority of individuals and did it in about 8 to 10 days, which is really good news from the standpoint of both the supply of vaccine and the fact that we have a vaccine that can induce that response.

MARGARET WARNER: So does this mean that more Americans can be protected and earlier?

DR. ANTHONY FAUCI: Well, it's certainly more Americans can be protected in numbers. But the fact is, when you say earlier, not necessarily getting the vaccine earlier, but when you get the vaccine, to get that protected response, to be induced earlier.

Usually, if it were two doses -- which it isn't, it's one -- you'd have to give a dose, wait 21 days, give another dose, and then two weeks later you'd expect a good potent immune response.

What we have here is one dose and, eight to 10 days later, we have a very good immune response, so that means that the time it takes from your vaccine to protection is very truncated. That's very good news.

Children might require two doses

MARGARET WARNER: Now, for parents out there, it's worth noting that these trials -- you haven't yet completed the trials about children, who are one of the most at -- children and teenagers, most at-risk groups. Is it possible that, when you get those results I think in a couple of weeks, that children may still need two doses?

DR. ANTHONY FAUCI: It's possible that some subsets of children might need two doses. This vaccine is acting very much like the seasonal flu vaccine. And with the seasonal flu vaccine, traditionally children from 9 years of age and older really require just one dose. Less than 9 years old are children, if they have prior experience with vaccination, they may not need two doses, but some of them certainly will.

So we're going to wait to see what the results of the trial are. But we really feel rather strongly that it's acting very much like seasonal flu vaccine, which is a good thing, because only a subset of those children will need two doses.

MARGARET WARNER: Now a question for people over 65. If someone reads the fine print of this study, it does appear that there's quite a difference in the immune response, people 64 and under versus those older. I think one product, in regular adults, you had 97 percent immune response, but in seniors over 65 only, what, 55 percent, 56 percent. Should older Americans be worried?

DR. ANTHONY FAUCI: Well, certainly, older Americans should pay attention to getting vaccinated, particularly with the seasonal flu.

MARGARET WARNER: That's the regular flu.

Lower responses in the elderly

DR. ANTHONY FAUCI: But first of all -- yes, the regular flu. But let me just address your question, Margaret, because it's important. Lower responses to vaccines, influenza vaccines, in the elderly is something that we see all the time. We'd love it to be higher, but it just is not.

So this is very much what we see in seasonal flu vaccine. This is not anything peculiar about the swine flu vaccine. It's just doing what we generally see every year.

But we should make sure that senior citizens realize that the threat to them of any flu is there, but particularly the seasonal flu that we get every year, because of the 36,000 deaths that occur each year with seasonal flu regularly, 92 percent of them are in individuals older than 65 years old.

So we want to tell our senior citizens to pay attention not only to the swine flu, but to getting their seasonal flu vaccine.

MARGARET WARNER: Now, you all have said that you expect the first big batch of this vaccine, like 40 million or 50 million doses, to arrive in mid-October.


MARGARET WARNER: Whom will it go to first?

DR. ANTHONY FAUCI: Well, what happens is that, when it arrives, it gets distributed to the states in a prorated way. And there's five target groups that have been identified by the CDC and their advisers as individuals who we want to make sure get the vaccine.

And that starts off with pregnant women. That's children 6 months of age to 24; people who are taking care of children less than 6 months old; health care workers; and adults who have underlying conditions that might make them more prone to the complications of influenza.

We want to make sure that those people get vaccinated, but everyone really should get vaccinated.

MARGARET WARNER: Now, there are many experts who have been predicting -- and, I mean, who knows -- but predicting that this swine flu will really peak here in mid-October. Is it possible that this vaccine will arrive too late?

Getting the vaccine in time

DR. ANTHONY FAUCI: Well, when you say peak, Margaret, it's important to point out that, if you look at the map of the nation and the seasonal flu or even with this pandemic flu, you don't have a homogeneous peaking. You may have some areas that get hit hard and, unfortunately, you may not get the vaccine to them in time.

We see the experience in Washington State University, where a couple of thousand students got infected. There was no vaccine for them. But there will be areas of the country that will benefit greatly from the time that the vaccine arrives.

Although vaccine is the primary way of prevention, there are a number of other things that you can do to prevent yourself from getting infected that would complement the vaccine. So if the vaccine isn't there, you pay attention to those things that are very clearly spelled out on the CDC's Web site.

MARGARET WARNER: Let me finally briefly ask you, there's a lot of concern among some Americans about the safety of vaccines and side effects, medium or long term. Do the clinical trials tell you anything about that? Or what else are you going to do to monitor that?

DR. ANTHONY FAUCI: Well, there are two issues. One, the immediate side effects, there are no what we call red-flag signals of safety problems with any of the trials that either we did or that the companies did. There has been some very minor issues, like pain at the site of injection, a little swelling, and sometimes redness. We see that with any time you have a vaccine in which you stick a needle in someone.

Regarding very rare adverse events, there really isn't any clinical trial that would be large enough to pick that up. So what you do is that you hope they don't occur, but the CDC and the FDA have in place a very, very rigid and robust surveillance mechanism after people get vaccinated to make sure you pick up that rare event. So all of those things are going to be operable.

MARGARET WARNER: Well, Dr. Anthony Fauci, thank you so much for being with us.

DR. ANTHONY FAUCI: It's good to be here.