Hepatitis C Direct-Acting Antivirals May Be the Solution to a Hep C Vaccine
Direct-acting antiviral medications are steadily turning the tide on the battle against Hepatitis C. With a treatment success rate in the high 90th percentile, more people than ever are able to eliminate Hepatitis C from their body. Although these drugs might seem to be the answer to the Hepatitis C pandemic, it is only one half of the solution.
Thanks largely to the rise in opioid addictions afflicting this country, the rate of new Hepatitis C infections continues to grow.
In the United States, an estimated 3 to 4 million people are chronically infected with Hepatitis C, with more than 30,000 new infections per year. Spreading through contaminated blood, experts estimate that at least 60 percent of new Hepatitis C infections are acquired from sharing needles, syringes, or other drug paraphernalia. The rise in opioid addictions frequently leads to heroin use – the most common drug requiring intravenous needle administration.
The direct-acting antiviral medications that have effectively changed the likelihood of successfully treating Hepatitis C are also capable of preventing transmission of the virus.
Although this seems like a win-win for direct-acting antivirals, the steep prices of these drugs are very prohibitive. Many injecting drug users lack access to healthcare in the U.S. to pay for direct-acting antivirals. Even if someone has insurance that would cover the cost of direct-acting antivirals, injection drug users can become infected again if they continue to share needles. In that case, an insurer is unlikely to cover the cost of Hepatitis C treatment a second time.
The U.S. Food and Drug Administration (FDA) has only approved direct-acting antiviral drugs for Hepatitis C within the past four years – meaning the companies that manufacture them have market exclusivity. Thus, only the original manufacturers can promote and sell their drugs. Because these drugs are relatively new, there are no generic versions yet. Generic medications are typically much cheaper than brand-name versions.
Hepatitis C Direct-Acting Antivirals
Below is a list of the currently used Hepatitis C direct-acting antivirals, and their costs (from most expensive to least expensive):
- Harvoni – $94,800
- Viekira Pak – $83,300
- Technivie – $78,100
- Vosevi – $75,600
- Epclusa – $75,000
- Zepatier – $55,700
- Mavyret – $26,400
According to findings published recently in the journal Science Translational Medicine, researchers conducted a mathematical modeling study to determine the likelihood of Hepatitis C transmission in those who inject drugs, and share needles and syringes.
The authors found that a Hepatitis C vaccine would dramatically reduce transmission of Hepatitis C among drug users – even though it’s unlikely such a vaccine would provide complete immunity.
Research Is Ongoing Into a Hepatitis C Vaccine
Unlike many other vaccines, the Hepatitis C vaccine is not expected to provide complete immunity, known as sterilizing immunity. Instead, it would likely reduce the amount of Hepatitis C in the bloodstream among those who contract the virus.
The model from the Science Translational Medicine finding estimated that:
- If a person who injects drugs shared syringes or needles with a person who injects drugs with Hepatitis C, the chance of transmitting the virus between them would be more than 90 percent in half a year.
- If uninfected individuals who inject drugs with equipment shared by someone with Hepatitis C had received a non-sterilizing vaccine, the risk of transmission would drop to between 1 and 25 percent (depending on the type of needle used and other factors).
Public Health Priority
The development of vaccines that protect against persistent Hepatitis C infection is a public health priority. According to study co-author Scott Cotler, MD, head of Loyola’s division of hepatology and a professor in the department of medicine of Loyola University Chicago Stritch School of Medicine, “Our findings suggest that a Hepatitis C vaccine would be an essential part of a comprehensive prevention strategy to meet the World Health Organization’s goal of eradicating Hepatitis C by 2030.”
The broad use of highly effective direct-acting antivirals is unlikely to achieve Hepatitis C elimination without vaccines that can limit viral transmission. According to Loyola researcher and co-senior author of this study, Harel Dahari, PhD, “We need to combine antivirals with a Hepatitis C vaccine and harm-reduction measures such as needle-syringe exchange programs, opioid substitution therapy and behavioral counseling.”
Considering the steep cost of the direct-acting antiviral Hepatitis C medications and the fact that injection drug users are the fastest growing group with new Hepatitis C infections, preventing transmission is vital to the goal of eradicating Hepatitis C. The new research indicates that even if imperfect (not providing complete immunity), with a treatment success rate in the high 90th percentile it is likely that Hepatitis C direct-acting antiviral medications may be the solution we need.
https://www.eurekalert.org/pub_releases/2018-07/luhs-hcv071018.php, Hepatitis C vaccine could dramatically reduce transmission in people who inject drugs, Retrieved August 4, 2018, American Association for the Advancement of Science, 2018.
https://www.frontiersin.org/articles/10.3389/fimmu.2018.01480/full, Hepatitis C Vaccines, Antibodies and T Cells, Naglaa H. Shoukry, Retrieved August 12, 2018, Frontiers in Immunology, June 2018.
https://www.healthline.com/health/hepatitis-c-treatment-cost#why-the-high-costs?, Hepatitis C Treatment Costs- What You Should Know, Retrieved August 12, 2018, Healthline Media, Inc., 2018.
https://www.hepmag.com/article/hep-c-vax-greatly-slow-transmission-among-people-inject-drugs, A Hep C Vax Could Greatly Slow Transmission Among People Who Inject Drugs, Benjamin Ryan, Retrieved August 4, 2018, Smart + Strong, 2018.