A sustained virologic response (SVR) for people with a hepatitis C infection simply means that no hepatitis C virus (HCV) can be found in blood at 12 and 24 weeks after completing a course of hepatitis C treatment. SVR very likely means that the HCV infection is cured, and has been used in studies as the ultimate goal of HCV therapy. In most cases, if HCV viral load remains undetectable 24 weeks after the completion of treatment, it remains undetectable for life.

In almost all cases, people with an SVR of 24 weeks are unlikely to experience viral rebound (i.e., a return of virus).

Defining SVR and Other Virologic Responses

Following the initiation of hepatitis C therapy, the blood is tested to measure the quantity of the hepatitis C virus (the viral load). The ultimate goal is to achieve an undetectable viral load. “Undetectable,” in this case, doesn’t necessarily mean zero or the complete absence of viral activity in the body; rather, it is defined as having no detectable virus in the blood using current testing technologies.

Each stage of response is given a classification, with some stages correlating to a greater or lesser likelihood of treatment success. Take a look at this chart, below.

Increasing Your Chances of Achieving SVR

One of the main determinants of SVR success is timing. Treatment, when you have been infected for a short time, is somewhat more likely to work than treatment in patients who have been infected for many years. By treating your infection before there is marked liver damage, you generally have a better chance of achieving a clinical cure for HCV.

Additionally, newer-class direct-acting antivirals (DAAs) have had a profound effect on SVR rates in people with chronic HCV infection. Even in people with compensated cirrhosis, who had previously had a 50/50 chance of treatment success, SVR rates have gradually climbed to 95 percent and above in many of these cases.

What Failing to Achieve SVR Means

While the goal of HCV therapy is to effectively eradicate the virus and to allow a person to live a healthy, hepatitis-free life, a patient shouldn’t despair if he or she is unable to achieve these goals. Even if you have only a partial response, studies have shown that the benefits to the liver can be profound—not only slowing the course of the disease but in some cases reversing fibrosis, even in those with marked liver damage.

If you fail your first or second round of therapy, take time to monitor your blood results with your healthcare provider. If you feel that you are ready to try again, your healthcare provider can perform a number of tests to determine which drugs may provide you with the best chance of achieving SVR success.

Reasons Why You May Not Achieve SVR

It’s not entirely clear why a small percentage of patients don’t reach SVR, but the following factors can play a role:

  • Failure to adhere to treatment or complete treatment The specific genotype of your hepatitis Underlying liver diseaseA drug-resistant virusConcurrent HIVBaseline viral loadAlcohol useAge

Coping With Hepatitis C

Don’t let a hepatitis C infection make you feel isolated. There is help available. Beyond asking your friends and family members to help you during your journey, you may find comfort joining the active hepatitis C community online or a chronic hepatitis support group. Also, learning more about chronic hepatitis nutrition can both make you feel better and potentially improve your treatment response.

  • Kattakuzhy, S., Wilson, E., Sidharthan, S. et al. Moderate Sustained Virologic Response Rates With 6-Week Combination Directly Acting Anti-Hepatitis C Virus Therapy in Patients With Advanced Liver Disease. Clinical Infectious Disease. 2016. 62(4):440-7. doi:10.1093/cid/civ897
  • Smith-Palmer, J., Cerri, K., and W. Valentine. Achieving Sustained Virologic Response in Hepatitis C: A Systematic Review of the Clinical, Economic and Quality of Life Benefits. BMC Infectious Disease. 2015. 15:19. doi:10.1186/s12879-015-0748-8
  • Chopra, S., and D. Muir. Treatment Regimens for Chronic Hepatitis C Virus Genotype 1. UpToDate. Updated 09/14/16.
  • Kattakuzhy, S., Wilson, E., Sidarthan, S. et al. Evolution of Resistance Associated Variants During Initial Treatment, Viral Failure, and Re-Treatment with Directly Acting Antiviral Therapy (NIH SYNERGY Trial). AASLD Liver Meeting; 2015; abstract 220.

By Charles Daniel

 Charles Daniel, MPH, CHES is an infectious disease epidemiologist, specializing in hepatitis.