Q&A: Vaccines Available to Protect Patients Against Hepatitis Viruses

With hepatitis A and B being the most prominent of all hepatitis viruses, both types have 3 available vaccines for all age groups up to 59 years of age. As some circumstances may lead specific populations to be at an increased risk of hepatitis, immunization access has increased as CDC guidelines expand the populations available to receive the vaccine.

“From a vaccine availability for hep A, we actually have 2 vaccines and a combination vaccine. We have Havrix and Vaqta, which are 2 Hepatitis A vaccines. They're interchangeable, according to the CDC, both over 95% protective after 2 doses, and immunity easily lasts more than 20 years,” said Jeff Goad, PharmD, MPH, President of the National Foundation for Infectious Diseases. “Now for the hepatitis B vaccines, we have 3 vaccines available. Two are the more older ones, which are the recombinant-based vaccines such as Engerix-B and Recombivax. But we also have a newer one called Heplisav-B. Now, we also have a combination vaccine of hepatitis A and B called Twinrix, approved only for adults”

"We have basically 5 main types of hepatitis that affect humans," said Goad. "That's hep A, B, C, D, and E." | image credit: Orawan / stock.adobe.com

Read through part 1 of our interview with Goad as he dives deep into what hepatitis viruses exist, what vaccines are available to combat them, and what populations are at the most risk of developing the disease. Also, stay tuned for more from our interview with Goad, who joined us in the month of May—Viral Hepatitis Awareness Month—to discuss the current state of the disease.

READ MORE: Potential Universal Vaccine Could Prevent Swine, Human, and Bird Flu

Drug Topics: Can you start by briefly explaining what hepatitis is and how it impacts a patients’ health?

Jeff Goad: As the name implies, hepatitis is really just an inflammation of the liver. It's actually most often caused by viral infections such as hep A, B, and C, and we'll talk a bit more about those. It can also result from alcohol use and abuse, toxins, autoimmune disorders, and some other things that may also lead to liver damage. And really, the impact of this has to do, when we think about chronic disease with hepatitis, like Hepatitis B and C, is the nature of it leading to things like cirrhosis, liver failure, and even liver cancer.

Hepatitis A, on the other hand, is mostly an acute infection, and it can lead to something like flu-like symptoms, jaundice, and fatigue, but in severe cases, can result in liver failure. Unlike hepatitis B, it doesn't have a chronic phase. Of course, both hep A and B have at the core prevention vaccines available.

Drug Topics: What hepatitis diseases exist and which vaccines are currently approved in the US to protect patients from hepatitis?

Jeff Goad: Well, I think first we start with hepatitis, the viruses themselves, which are interesting in that the only thing they really have in common is that they affect the liver. Otherwise, the viruses are actually very different that cause hepatitis. We have basically 5 main types of hepatitis that affect humans. That's hep A, B, C, D, and E. We'll take each of them, but really kind of focus more on hep A and B that we can actually do something about. When I say they're different, they differ even in the type of vaccine from the genetic level. For example, hepatitis A is an RNA virus. As I said before, it causes acute liver infection, but it's spread by the fecal-oral route. So, mainly you get this from contaminated food and water. And of course, it is vaccine preventable. Whereas hepatitis B is actually a DNA virus and it's transmitted differently than hep A. It's blood borne, it's sexually transmitted through injection drug use, and even perinatally from mother to child. And of course, this one, like hep A, is also vaccine preventable.

That gets us into the rest of them that are not vaccine preventable, such as hepatitis C, that a while back used to be called non-A non-B, now named as hepatitis C. It also causes a chronic liver infection, just like Hepatitis B, but no vaccine available. Then hepatitis D, interestingly enough, only affects individuals who have hepatitis B, so kind of a strategy to protect or prevent against hepatitis D is to get vaccinated against hepatitis B. And then last is hep E, which is transmitted more similarly to hepatitis A through contaminated water. But fortunately, it's very rare in the United States.

That leads us then to well, what vaccines are available to actually prevent these types of hepatitis? On the inactivated side, all of our vaccines that we use for hep A and B are inactivated. They're all made a little differently, but it's important to know there are no live vaccines in the hepatitis A and B area. From a vaccine availability for hep A, we actually have 2 vaccines and a combination vaccine. We have Havrix and Vaqta, which are 2 Hepatitis A vaccines. They're interchangeable, according to the CDC, both over 95% protective after 2 doses, and immunity easily lasts more than 20 years. Now, we also have a combination vaccine of hepatitis A and B called Twinrix, approved only for adults, but interestingly enough, the hepatitis A component in Twinrix is actually pediatric strength, meaning that you have to give 3 doses of the Twinrix to be equivalent to 2 doses of adult hepatitis A. So, if you are going to use the Twinrix vaccine, you do need to complete the series.

Now for the hepatitis B vaccines, we have 3 vaccines available. Two are the more older ones, which are the recombinant-based vaccines such as Engerix-B and Recombivax. But we also have a newer one called Heplisav-B. And then, of course, we still have the combination vaccine, Twinrix, which does have full-strength recombinant vaccine for type B in it. Now, the effectiveness of all these vaccines [is] easily over 95% and immunity lasts for decades. Both the hep A and B get very long-lasting immunity. They do differ on their schedules. For example, the recombinant vaccines, Engerix and Recombivax, need to have 3 doses, and you can start them at birth. Remember, this is the only vaccine that's available to be given at birth is the hepatitis B. Now, the Heplisav-B, however, is approved for adults, so 18 and over, and it's a 2-dose series, so you only have to use 2 versus 3 doses. But it is focused in on the adult population.

And then of course, how do we decide who gets these vaccines? A lot of them are based on categories such as behaviors. For example, what you eat, or we've seen outbreaks of hep A in homeless population. There are some social, behavioral aspects. Sexually transmitted diseases, again, [are] under the behavioral. Then, of course, there's where you live and work. Health care workers, for example, are at risk for hepatitis B, but not hep A vaccine, and we want to make sure that they get vaccinated. And then, of course, travel risk for both hep A and B. But most people think of hep A when they think of travel to endemic regions, which mostly is the entire world minus a few developed countries. Then, of course, medical risks; people who already have chronic liver disease should be vaccinated against hep A and B as well. Lastly, some post-exposure. For example, if you got the bad raspberries from an outbreak from a grocery store, you might be advised to get hep A vaccine. It does work post-exposure, as well as hep B for post-high-risk exposures as well.

There are several reasons why you might use the vaccine, and we can maybe get into some of those, especially in those over 60 where the universal recommendation for hepatitis B ends. So remember, for vaccination strategies, our hep A, we give it to all of our kids, starting at 1 year of age, and then we catch up adults. For hep B, as I mentioned before, we start it at birth, but we can also catch that up all the way through childhood, through 19—18-year-olds are considered children by the CDC, so that's why it's on that table. But now we also have universal guidelines, recommendations, to use the hep B vaccine all the way to 59. You might wonder why over 60? It's a risk-benefit calculation the CDC did, but there are some individuals over 60; for example, those who are maybe going to have new sexual partners, increasing the risk of sexually transmitted infection. Those with diabetes actually are at greater risk, and that mostly came out of studies looking at sharing of Lancet devices to test for blood glucose. And of course, if you're a health care worker, over 60, you got a new job, you might need to get the hepatitis B vaccine, and residents in long-term care facilities might be at greater risk. Again, that goes back to the diabetes risk around diabetes and blood glucose testing. That's sort of a little explanation of the vaccines that we have available to prevent hepatitis A and B.

READ MORE: Immunization Resource Center

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