What Are Therapeutic Vaccines?

Shots intended to treat disease rather than prevent it

Traditionally, vaccines are designed to stimulate the immune system so that it can prevent disease-causing organisms (pathogens) from establishing an infection. But there are some shots—called therapeutic vaccines—that stimulate the immune system so that it can treat certain diseases and/or slow their progression.

Although the field of therapeutic vaccines remains largely experimental, three such vaccines—all of which are used to treat cancer—have been approved for use by the U.S. Food and Drug Administration (FDA).

Person receiving a shot
Jeffrey Hamilton / Digital Vision / Getty Images

Much of the focus of current research has been placed on creating therapeutic vaccines for cancer, but other scientists are aiming to develop therapeutic vaccines to treat HIV, human papillomavirus (HPV), viral hepatitis, cholera, and other potentially serious diseases.

How Therapeutic Vaccines Work

Traditional vaccines stimulate the production of antibodies, immune proteins that target specific pathogens like viruses or bacteria. Similarly, therapeutic vaccines stimulate the immune system to target cancer cells or control the progression of chronic infections like HIV.

Unlike traditional vaccines that are given before a person gets a disease to defend against infection, therapeutic vaccines are given after a person gets a disease to mount a more robust, disease-specific offense.

There are two different approaches to the development of therapeutic vaccines:

  • Autologous vaccines are a form of personalized medicine in which cells from a person's own body (such as cancer cells or immune cells) are harvested to make a vaccine for that person.
  • Allogeneic vaccines are created from cells that are harvested from others and/or engineered in the lab. This is the approach most commonly used to develop therapeutic vaccines for cancer.

From these cells, scientists can create different types of therapeutic vaccines with distinct mechanisms of action. These include antigenic vaccines, dendritic vaccines, and DNA vaccines.

Antigenic Vaccines

Antigenic vaccines involve antigens, substances that provoke a specific antibody response. The antigen may be a weakened (live attenuated) pathogen, a dead (inactivated) pathogen, a fragment (subunit) of a pathogen, or a substance produced by a pathogen.

These include tumor antigens produced by cancer cells that, when harvested and introduced into the body, amplify the immune response to better fight the cancer cells from which they were produced.

Dendritic Vaccines

Dendritic vaccines involve a type of white blood cell called a dendritic cell that is part of the body's innate immune system. These are the frontline cells that look for pathogens and attack before the immune system is able to launch a disease-specific antibody response.

By harvesting these cells and inoculating them with cancer cells or inactivated viruses, it is thought that they can "learn" to recognize tumors or chronic viral infections and attack more aggressively.

DNA Vaccine

Therapeutic DNA vaccines are designed to send encoded instructions to cells so that they can render a disease-specific immune response.

DNA vaccines can hypothetically "boost" immunity to help overcome immune exhaustion caused when a long-time infection (such as HIV) diminishes the immune system's ability to recognize a pathogen.

What's Approved and What's in Development

Although only three therapeutic vaccines have received FDA approval to date, there are others that have shown enormous promise in treating different cancers or viral infections.

For Cancer

The greatest strides in therapeutic vaccine research have been in the treatment of cancer.

Of the three vaccines approved for use in the United States, two are used to treat advanced cancer that has spread to distant parts of the body (metastatic disease), while the other is used to prevent the progression of carcinoma in situ (a precancer condition).

The approved vaccines, from oldest to newest, are:

Other therapeutic vaccines for cancer that are in development include:

For Human Papillomavirus (HPV)

Vaccine researchers are looking for ways to improve the clearance of human papillomavirus (HPV) from the body after infection. Although clearance of the virus occurs on its own in the majority of cases, there are some in whom the infection will persist and lead to cervical cancer, anal cancer, and other types of cancers later in life.

While there are vaccines that can prevent HPV, there are none that can treat HPV infection after it has occurred. Finding one is considered imperative given that 90% of men and women in the United States will be exposed to HPV at some point in their lives.

Research into the development of therapeutic HPV vaccines often overlaps with that of targeted cancer therapies. This is because many of the vaccine candidates aren't designed to attack the virus, but the tumors it causes.

Among some of the HPV candidates currently under investigation are:


There are no therapeutic vaccines approved for the treatment of HIV, but encouraging results are beginning to emerge from early clinical research.

Much of the research is based on a rare subset of people known as long-term non-progressors who are able to avoid HIV disease progression despite being infected. Many of these individuals have unique, broadly-neutralizing antibodies (bnAbs) that can fend off up to 99% of all HIV strains.

Scientists hope to replicate this effect with therapeutic vaccines, leading to a functional cure for HIV (i.e., one in which the infection remains but without symptoms or disease progression). The vaccines may also help overcome immune exhaustion in people on antiretroviral therapy who are unable to achieve immune recovery.

For Herpes Simplex Virus

Herpes simplex virus (HSV) is also being explored in therapeutic vaccine research. Because scientists understand more about why the virus will suddenly reactivate after being dormant and cause herpes outbreaks, research has been focused on creating a vaccine that can continually suppress the virus without the use of antiviral drugs.

If successful, therapeutic HSV vaccines will reduce viral shedding, a phenomenon in which the virus suddenly replicates, increasing the concentration of virus in tissues and bodily fluids. Shedding not only intensifies during an acute herpes outbreak but increases the risk of transmission to others.

Several therapeutic vaccine candidates have shown promise in reducing HSV shedding and lesions in early research, including:

  • HSV529, a vaccine that uses a replication-defective virus that can induce a stable antibody response without causing disease
  • Delta gD-2, a vaccine that utilizes a genetically altered herpes virus
  • GSK4108771A, a novel vaccine that uses messenger RNA (mRNA)—the same technology that enabled the development of the Moderna and Pfizer COVID-19 vaccines

Hepatitis B

Because there is no cure for hepatitis B (unlike hepatitis C), therapeutic vaccines are seen as a way to slow the progression of a disease that can cause cirrhosis, liver failure, and liver cancer in some.

By stimulating the appropriate immune response, a vaccine may be able to reduce the hepatitis B viral load (the measure of viral activity). A high viral load correlates with faster disease progression.

Some of the more promising therapeutic vaccine candidates for hepatitis B are:

  • GS-4774, an antigen vaccine that includes yeast-based adjuvant (a substance that induces a more robust immune response)
  • HBsAg-HBIG, another antigen vaccine that contains an aluminum-based adjuvant
  • HBsAg/HBcAg, an antigen vaccine that combines two different hepatitis antigens (one from the surface of the virus and one from the core)

A Word From Verywell

Therapeutic vaccines are an exciting field of vaccine research. With three FDA-approved vaccines serving as proof of concept, the field is likely to expand as scientists learn more about the mechanisms that cause disease progression. By blocking them, a disease is not cured, per se, but it may be far less able to cause illness.

Despite the enthusiasm surrounding therapeutic vaccines, it is still a young field of research. It will be likely years before an effective one for viral diseases like HIV, hepatitis B, or HPV is available. Until then, it is important to focus on prevention to avoid getting these potentially serious infections.

19 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Gulley JL. The ultimate personalized therapy? Hum Vaccin Immunother. 2013;9(1):219-21. doi:10.4161/hv.22106

  2. Parmiani G, Pilla L, Maccalli C, Russo V. Autologous versus allogeneic cell-based vaccines? Cancer J. 2011;17(5):331-6. doi:10.1097/PPO.0b013e3182337a76

  3. Wang XY, Wang B, Wen YM. From therapeutic antibodies to immune complex vaccines. NPJ Vaccines. 2019;4:2. doi:10.1038/s41541-018-0095-z

  4. Tagliamonte M, Petrizzo A, Tornesello ML, Buonaguro FM, Buonaguro L. Antigen-specific vaccines for cancer treatment. Hum Vaccin Immunother. 2014;10(11):3332-46. doi:10.4161/21645515.2014.973317

  5. Mastelic-Gavillet B, Balint K, Boudousquie C, Gannon PO, Kandalaft LE. Dendritic cell vaccines—recent breakthroughs and encouraging clinical results. Front Immunol. 2019;10:766. doi:10.3389/fimmu.2019.00766

  6. Cheng MA, Farmer E, Huang C, Lin J, Hung CF, Wu TC. Therapeutic DNA vaccines for human papillomavirus and associated diseases. Hum Gene Ther. 2018;29(9):971-96. doi:10.1089/hum.2017.197

  7. Organon Teknika. Package insert - Tice.

  8. Dendreon Pharmaceuticals. Package insert - Provenge.

  9. Amgen. Package insert - Imlygic.

  10. Jou J, Harrington KJ, Zocca MB, Ehrnrooth E, Cohen EEW. The changing landscape of therapeutic cancer vaccines-novel platforms and neoantigen identification. Clin Cancer Res. 2021;27(3):689-703. doi:10.1158/1078-0432.CCR-20-0245

  11. Morrow MP, Yan J, Sardesai NY. Human papillomavirus therapeutic vaccines: targeting viral antigens as immunotherapy for precancerous disease and cancer. Expert Rev Vaccines. 2013;12(3):271-83. doi:10.1586/erv.13.23

  12. Centers for Disease Control and Prevention. Sexually transmitted disease surveillance.

  13. Rumsfield CS, Roller N, Pellom ST, Schlom J, Jochems C. Therapeutic vaccines for HPV-associated malignancies. Immunotargets Ther. 2020;9:167-200. doi:10.2147/ITT.S273327

  14. Mylvaganam GH, Silvestri G, Amara RR. HIV therapeutic vaccines: moving towards a functional cure. Curr Opin Immunol. 2015;35:1-8. doi:10.1016/j.coi.2015.05.001

  15. Workowski KA, Bachmann LH, Chan PA, et al. Sexually transmitted infections treatment guidelines, 2021MMWR Recomm Rep. 2021;70(4):1-187. doi:10.15585/mmwr.rr7004a1

  16. Dropulic LK, Oestreich MC, Pietz HL, et al. A randomized, double-blinded, placebo-controlled, phase 1 study of a replication-defective herpes simplex virus (HSV) type 2 vaccine, HSV529, in adults with or without HSV infection. J Infect Dis. 2019;220(6):990-1000. doi:10.1093/infdis/jiz225

  17. Hook LM, Awasthi S, Dubin J, Flechtner J, Long D, Friedman HM. A trivalent gC2/gD2/gE2 vaccine for herpes simplex virus generates antibody responses that block immune evasion domains on gC2 better than natural infection. Vaccine. 2019;37(4):664-9. doi:10.1016/j.vaccine.2018.11.076

  18. ClinicalTrials.gov. A study on the reactogenicity, safety and immune response of a vaccine against herpes simplex virus (HSV)-2 in healthy participants aged 18-40 years.

  19. Al-Mahtab M, Akbar SMF, Aguilar JC, et al. Therapeutic potential of a combined hepatitis B virus surface and core antigen vaccine in patients with chronic hepatitis BHepatol Int. 2013;7:981-9. doi:10.1007/s12072-013-9486-4

By Elizabeth Boskey, PhD
Elizabeth Boskey, PhD, MPH, CHES, is a social worker, adjunct lecturer, and expert writer in the field of sexually transmitted diseases.