Vaccine

Measles Vaccine

The only measles virus vaccine now available in the United States is a live, more attenuated Enders-Edmonston strain (formerly called “Moraten”). The vaccine is available as a single antigen preparation, combined with rubella vaccine, or combined with mumps and rubella vaccines. The ACIP recommends that combined measles-mumps-rubella vaccine (MMR) be used when any of the individual components is indicated. Measles vaccine is prepared in chick embryo fibroblast tissue culture. MMR is supplied as a lyophylized (freeze-dried) powder and is reconstituted with sterile, preservative-free water. The vaccine contains a small about of human albumin, neomycin, sorbitol, and gelatin.

Immunogenicity and vaccine efficacy

Measles vaccine produces an inapparent or mild, noncommunicable infection. Measles antibodies develop in approximately 95% of children vaccinated at 12 months of age and 98% of children vaccinated at 15 months of age. Approximately 2%-5% of children who receive only one dose of MMR vaccine fail to respond to it (i.e., primary vaccine failure). MMR vaccine failure may occur because of passive antibody in the vaccine recipient, damaged vaccine, incorrect records, and possibly other reasons. Most children who fail to respond to the first dose will respond to a second dose. Studies indicate that more than 99% of persons who receive two doses of measles vaccine (with the first dose administered no earlier than the first birthday) develop serologic evidence of measles immunity.

Although the titer of vaccine-induced antibodies is lower than that following natural disease, both serologic and epidemiologic evidence indicate that vaccine-induced immunity appears to be long-term and probably life-long in most individuals. Most vaccinated persons who appear to lose antibody show an anamnestic immune response upon revaccination indicating that they are probably still immune.

Vaccination of adults

Adults born in 1957 or later who do not have a medical contraindication should receive at least one dose of MMR vaccine unless they have documentation of vaccination with at least one dose of measles-, rubella-, and mumps-containing vaccine or other acceptable evidence of immunity to these three diseases.

Although birth before 1957 is generally considered acceptable evidence of measles and rubella immunity, medical facilities should consider recommending a dose of MMR vaccine to unvaccinated workers born before 1957 who do not have a history of prior measles disease or laboratory evidence of measles immunity, and those without laboratory evidence of rubella immunity.

Certain groups of adults may be at increased risk for exposure to measles and should receive special consideration for vaccination. These persons include:
  • persons attending colleges and other post-high school educational institutions
  • persons working in medical facilities and
  • international travelers.

Colleges and other post-high school educational institutions are potential high-risk areas for measles, rubella, and mumps transmission because of large concentrations of susceptible persons. Prematriculation vaccination requirements for measles immunity have been shown to significantly decrease the risk of measles outbreaks on college campuses where they are implemented and enforced.

All persons who work within medical facilities should have evidence of immunity to measles and rubella. Because any health care worker (i.e., medical or non-medical, paid or volunteer, full time or part time, student or non-student, with or without patient-care responsibilities) who is measles or rubella susceptible can contract and transmit these diseases, all medical facilities (i.e., inpatient and outpatient, private and public) should ensure measles and rubella immunity among those who work within their facilities (a possible exception might be a facility that treats only elderly patients considered at low risk for measles and rubella and their complications). Adequate vaccination for measles and rubella for health care workers born during or after 1957 consists of two doses of a live measles-containing vaccine and at least one dose of a live rubella-containing vaccine. Health care workers needing a second dose of measles-containing vaccine should be revaccinated at least 4 weeks after their first dose.

Travelers outside of the United States are at increased risk of exposure to measles. Measles is endemic or epidemic in many countries throughout the world. Although proof of immunization is not required for entry into the United States, persons traveling or living abroad should have evidence of measles immunity. Adequate vaccination of persons who travel outside the United States is two doses of MMR.

Post-exposure prophylaxis

Live measles vaccine provides permanent protection and may prevent disease if given within 72 hours of exposure. Immune globulin (IG) may prevent or modify disease and provide temporary protection if given within 6 days of exposure.

Measles immunity

Persons generally can be considered immune to measles if they:

  • 1) were born before 1957
  • 2) have documentation of physician-diagnosed measles
  • 3) have laboratory evidence of immunity to measles, or
  • 4) have documentation of adequate vaccination

Vacinne side effects

  • Transient lymphadenopathy sometimes occurs following receipt of MMR or other rubella-containing vaccine
  • Parotitis has been reported rarely following receipt of MMR or other mumps-containing vaccine
  • Arthralgias and other joint symptoms are reported in up to 25% of susceptible adult women given MMR vaccine (This adverse event is associated with the rubella component)
  • Allergic reactions following the administration of MMR or any of its component vaccines are rare. Most of these reactions are minor and consist of a wheal and flare or urticaria at the injection site
  • Immediate, anaphylactic reactions to MMR or its component vaccines are extremely rare
  • Allergic reactions including rash, pruritus, and purpura have been temporally associated with mumps vaccination, but are uncommon and usually mild and of brief duration.
  • To date there is no convincing evidence that any vaccine can cause autism or any kind of behavioral disorder. A suspected link between MMR vaccine and autism has been suggested by some parents of children with autism. Typically, symptoms of autism are first noted by parents as their child begins to have difficulty with delays in speaking after age one. MMR vaccine is first given to children at 12 to 15 months of age. Therefore autism cases with an apparent onset within a few weeks after MMR vaccination may simply be an expected but unrelated chance occurrence.

Contraindications and Precautions to Vaccination

  • Persons who have experienced a severe allergic reaction
  • Persons with a history of anaphylactic reactions following egg ingestion
  • Pregnant women
  • Persons who are immunosuppressed or immunodeficient
  • Persons receiving large daily doses of corticosteroids
  • Patients with leukemia in remission
  • Asymptomatic HIV-infected persons
  • Persons with moderate to severe acute illness
  • Persons who have a history of thrombocytopenic purpura or thrombocytopenia

- Persons who have experienced a severe allergic reaction (i.e., hives, swelling of the mouth or throat, difficulty breathing, hypotension, shock) following a prior dose of measles vaccine or to a vaccine compo-nent (e.g., gelatin, neomycin), should generally not be vaccinated with MMR.

- In the past, persons with a history of anaphylactic reactions following egg ingestion were considered to be at increased risk of serious reactions after receipt of measles- or mumps-containing vaccines, which are produced in chick embryo fibroblasts. However, recent data suggest that anaphylactic reactions to measles- and mumps-containing vaccines are not associated with hypersensitivity to egg antigens, but to other components of the vaccines (such as gelatin). The risk for serious allergic reactions following receipt of these vaccines by egg-allergic persons is extremely low and skin-testing with vaccine is not predictive of allergic reaction to vaccination. Therefore, MMR may be administered to egg-allergic children without prior routine skin testing or the use of special protocols.

- Pregnancy should be avoided for 1 month following receipt of measles vaccine and 3 months following MMR vaccine. Close contact with pregnant women is NOT a contraindication to MMR vaccination of the contact. Breastfeeding is NOT a contraindication to vaccination of either the woman or the breastfeeding child.

- Replication of vaccine viruses can be prolonged in persons who are immunosuppressed or immunodeficient. Severe immunosuppression can be due to a variety of conditions, including congenital immunodeficiency, HIV infection, leukemia, lymphoma, generalized malignancy, or therapy with alkylating agents, antimetabolites, radiation, or large doses of corticosteroids. Evidence based on case reports has linked measles vaccine virus infection to subsequent death in six severely immunocompromised persons. For this reason, patients who are severely immunocompromised for any reason should not be given MMR vaccine. Healthy susceptible close contacts of severely immunocompromised persons may be vaccinated.

- In general, persons receiving large daily doses of corticosteroids (>2 mg/kg per day or >20 mg per day of prednisone) for 14 days or more should not receive MMR vaccine because of concern about vaccine safety. MMR and its component vaccines should be avoided for at least one month after cessation of high dose therapy. Persons receiving low dose or short course (less than 14 days) therapy, alternate-day treatment, maintenance physiologic doses, or topical, aerosol, intra-articular, bursal, or tendon injections may be vaccinated. Although persons receiving high doses of systemic corticosteroids daily or on alternate days during an interval of less than 14 days generally can receive MMR or its component vaccines immediately after cessation of treatment, some experts prefer waiting until two weeks after completion of therapy.

- Patients with leukemia in remission who have not received chemotherapy for at least 3 months may receive MMR or its component vaccines. Measles disease may be severe in persons with HIV infection. Available data indicate that vaccination with MMR has not been associated with severe or unusual adverse events in HIV-infected persons without evidence of severe immunosuppression, although antibody responses have been variable.

- MMR vaccine is recommended for all asymptomatic HIV-infected persons, and should be considered for symptomatic persons who are not severely immunosuppressed. Asymptomatic children do not need to be evaluated and tested for HIV infection before MMR or other measles-containing vaccines are administered. A theoretical risk of an increase (probably transient) in HIV viral load following MMR vaccination exists because such an effect has been observed with other vaccines. The clinical significance of such an increase is not known.

- Persons with moderate to severe acute illness should not be vaccinated until the illness has resolved. This precaution is intended to prevent complicating the management of an ill patient with a potential vaccine adverse event, such as fever. Minor illness (e.g., otitis media, mild upper respiratory infections), concurrent antibiotic therapy, and exposure or recovery from other illness are not contraindications to measles vaccination.

- Persons who have a history of thrombocytopenic purpura or thrombocytopenia may be at increased risk for developing clinically significant thrombocytopenia after MMR vaccination. No deaths have been reported as a direct consequence of vaccine-induced thrombocytopenia. The decision to vaccinate with MMR depends on the benefits of immunity to measles, mumps, and rubella and the risks for recurrence or exacerbation of thrombocytopenia after vaccination or during natural infection with measles or rubella. The benefits of immunization are usually greater than the potential risks, and administration of MMR vaccine is justified, because of the even greater risk for thrombocytopenia after measles or rubella disease. However, deferring a subsequent dose of MMR vaccine may be prudent if the previous episode of thrombocytopenia occurred within 6 weeks after the previous dose of the vaccine. Serologic evidence of measles immunity in such persons may be sought in lieu of MMR vaccination.

Source : WHO's document about measles