Pharmacology · Class
Viral vaccines !
Vaccines that train the immune system against a virus before infection: hepatitis B, HPV, influenza, measles, polio, rabies, yellow fever and others.
Updated 2026-11-01
What they are
Products that present a viral antigen so the body builds antibodies and memory before meeting the real virus. They come in three broad types: live attenuated viruses (measles, mumps, rubella, varicella, yellow fever, rotavirus, oral polio, the TAK-003 dengue vaccine), inactivated whole viruses (inactivated polio, hepatitis A, rabies, most influenza vaccines) and purified or recombinant proteins (hepatitis B surface antigen, HPV L1 virus-like particles, zoster glycoprotein E, RSV prefusion F). Combination vaccines such as MMR (triple viral) and MMRV are described on each component's page. In Colombia they are given free through the Programa Ampliado de Inmunizaciones (PAI) of MinSalud.
Mechanism of action
They produce active immunity. Antigen-presenting cells take up the viral protein, helper T cells and B cells are activated, and neutralising antibodies and memory cells remain. Neutralising antibodies usually target the protein the virus uses to attach to or enter the cell (haemagglutinin, envelope glycoprotein, capsid protein). Live attenuated vaccines replicate weakly, so they also induce cellular and, when given by mouth, mucosal immunity, but they can harm people with weak immune systems.
Target: Adaptive immune system (B and T cells) against viral surface or capsid proteins
Drugs in this class
- Hepatitis B vaccineRecombinant hepatitis B surface antigen (HBsAg) made in yeast. It prevents chronic hepatitis B and, with it, cirrhosis…Hepatitis B virus surface antigen (HBsAg)
- Human papillomavirus (HPV) vaccineVirus-like particles made of the HPV L1 capsid protein. It prevents infection by the types that cause most cervical…HPV major capsid protein L1
- Influenza vaccineSeasonal vaccine against influenza A and B. Its composition is updated every year because the virus's surface proteins…Influenza haemagglutinin (HA)
- Measles vaccineLive attenuated measles virus, given as MMR (triple viral, with mumps and rubella) or MR. Two doses protect almost…Measles virus haemagglutinin (H protein)
- Poliomyelitis vaccine (IPV and OPV)Two types: inactivated injectable vaccine (IPV) and live oral vaccine (OPV). OPV gives gut immunity; IPV cannot cause…Poliovirus capsid
- Rabies vaccineInactivated cell-culture vaccine. With wound washing and, in severe exposures, rabies immunoglobulin, it prevents a…Rabies virus glycoprotein (G)
- Rotavirus vaccineLive oral vaccine that prevents severe rotavirus diarrhoea in infants. It carries a small risk of intussusception, so…Rotavirus outer capsid protein VP7
- Varicella vaccineLive attenuated varicella-zoster virus (Oka strain). It prevents chickenpox and is also used soon after exposure.Varicella-zoster virus glycoprotein E (gE)
- Yellow fever vaccineLive attenuated 17D virus. One dose gives lifelong protection. It is part of Colombia's national schedule and is free…Yellow fever virus envelope protein (E)
- Dengue vaccineLive attenuated tetravalent vaccines. WHO recommends TAK-003 for children aged 6–16 in high-transmission settings…Dengue virus envelope protein (E)
- Hepatitis A vaccineInactivated whole hepatitis A virus with aluminium adjuvant. It prevents hepatitis A and can be used soon after…Hepatitis A virus capsid
- Mumps vaccineLive attenuated mumps virus (Jeryl Lynn strain and others), given as part of MMR (triple viral). It prevents mumps and…Mumps virus haemagglutinin-neuraminidase (HN)
- Respiratory syncytial virus (RSV) vaccinePrefusion F protein vaccine. Given in late pregnancy, the mother's antibodies cross the placenta and protect the baby…RSV fusion glycoprotein (F) in the prefusion conformation
- Rubella vaccineLive attenuated rubella virus (RA 27/3), given as MMR or MR. Its main purpose is to prevent congenital rubella syndrome.Rubella virus envelope glycoprotein E1
- Zoster vaccine (recombinant)Recombinant glycoprotein E with the AS01B adjuvant. It is not live and prevents shingles and postherpetic neuralgia in…Varicella-zoster virus glycoprotein E (gE)
Others in the class
- Ebola vaccine
- Hepatitis E vaccine
- Japanese encephalitis vaccine
- Mpox vaccine
- Tick-borne encephalitis vaccine
- COVID-19 vaccines
Test yourself
Think of the answer, then tap the question to see it.
Why are live attenuated vaccines avoided in severe immunosuppression?
The weakened virus still replicates; without a working immune system it can spread and cause disease.
Which three viral vaccines are not live?
For example hepatitis B (recombinant surface antigen), HPV (L1 virus-like particles) and inactivated polio; rabies, hepatitis A and recombinant zoster are also non-live.
Which viral protein do neutralising antibodies usually target?
The protein the virus uses to attach to or enter cells, such as influenza haemagglutinin, the measles H protein or the rabies glycoprotein.
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Chapter 13: Measles | Pink Book | CDC (Centers for Disease Control and Prevention, 2021); Chapter 18: Poliomyelitis | Pink Book | CDC (Centers for Disease Control and Prevention, 2021); Lineamiento Técnico y Operativo de la Primera Jornada Nacional de Vacunación (Ministerio de Salud y Protección Social (Colombia), 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
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Representative model, for educational purposes only.