From the Guidelines
Live vaccines, including MMR (Measles, Mumps, and Rubella) vaccine, are a type of vaccine that contains weakened forms of the disease-causing pathogen, which can replicate in the body without causing illness, and include viral vaccines like MMR, varicella, rotavirus, yellow fever, and intranasal influenza vaccines, as well as bacterial vaccines such as oral typhoid and BCG for tuberculosis. The main types of live vaccines are:
- Viral vaccines: MMR (Measles, Mumps, and Rubella), varicella (chickenpox), rotavirus, yellow fever, and intranasal influenza vaccines
- Bacterial vaccines: oral typhoid and BCG (Bacillus Calmette-Guérin) for tuberculosis These vaccines provide robust, long-lasting immunity because they closely mimic natural infection, stimulating both antibody and cell-mediated immune responses, as noted in studies such as 1. However, they are generally contraindicated in people with compromised immune systems, pregnant women, and sometimes in household contacts of immunocompromised individuals, as indicated in 1. The MMR vaccine specifically contains attenuated strains of measles, mumps, and rubella viruses and is typically administered in two doses—the first at 12-15 months and the second at 4-6 years of age, as recommended in 1 and 1. Live vaccines work by allowing the weakened pathogen to replicate enough to trigger an immune response without causing disease, creating immunological memory that protects against future infections, as explained in 1, 1, and 1. It's also important to note that the simultaneous administration of live and inactivated vaccines does not impair antibody responses or increase rates of adverse reactions, as stated in 1 and 1. Additionally, the administration of combined MMR vaccine yields results similar to administering individual measles, mumps, and rubella vaccines at different sites, as noted in 1 and 1. Overall, live vaccines are an essential tool in preventing infectious diseases and providing long-term immunity, but their use must be carefully considered in certain populations, such as those with compromised immune systems, as indicated in 1, 1, and 1.
From the Research
Types of Live Vaccines
- Live attenuated vaccines, such as measles, mumps, rubella, and varicella vaccines, which are composed of viral or bacterial strains that are deprived of their pathogenicity but can still replicate in the organism 2
- MMR (Measles, Mumps, and Rubella) vaccine, which is a combination of live attenuated vaccines against measles, mumps, and rubella viruses 3, 4
- MMRV (Measles, Mumps, Rubella, and Varicella) vaccine, which is a combination of the MMR vaccine and the varicella zoster virus vaccine 3, 4
- Oral poliomyelitis vaccine, which is composed of three attenuated strains prepared from the three wild virus types 2
- Yellow fever vaccine, which is a live attenuated vaccine against yellow fever virus 5
- Varicella vaccine, which is a live attenuated vaccine against varicella zoster virus 3, 4, 5
- Oral typhoid vaccination (OTV), which is a live attenuated vaccine against typhoid fever 5
Characteristics of Live Vaccines
- Live vaccines can provoke a non-pathogenic infection in vaccinated subjects, inducing an antibody and a cellular immune response 2
- Live vaccines can be administered concurrently with other vaccines, such as measles-mumps-rubella vaccine and varicella vaccine, without affecting their immunogenicity 6
- Live vaccines can be given to infants as young as 12 months of age, and can be administered in combination with other vaccines, such as diphtheria, tetanus, acellular pertussis, hepatitis B, inactivated poliovirus, and Haemophilus influenzae type b conjugate vaccine 3