Recommendations for Use - RubellaIAPCOI recommends the use of MMR vaccine instead of monovalent rubella vaccine so as to provide additional protection against mumps and measles. Recommendations for use of MMR are discussed below. |
Recommendations for Use - MMRFor the purposes of universal immunization, the vaccine should be introduced in those areas where immunization coverage is at least 80% and can be sustained on a long term basis, failing which an epidemiologic shift and increase in CRS may occur. For this reason MMR vaccine has been introduced in those Indian states where measles coverage is at least 70%. Simultaneously a system for surveillance for CRS and catch up immunization for all adolescent girls should also be instituted. The MMR vaccine in EPI improves protection against measles by immunizing those who have missed measles vaccine or failed to seroconvert to the first dose of vaccine, should reduce burden of CRS and provides added protection against mumps. For office practice the IAPCOI recommends offering MMR vaccine to all parents who can afford the vaccine (Category 2). This use of MMR in the private sector is unlikely to impact the epidemiology of rubella at present but must be carefully monitored. Two doses are recommended one at the age of 12-15 months and second at school entry (4-6 years) or at any time 4-8 weeks after the first dose. The second dose of MMR vaccine is to protect children failing to seroconvert against primarily mumps and less commonly against rubella (primary vaccine failures). In a child aged 12 months or older who has not received measles vaccine, 2 doses of MMR at 8 weeks interval suffices, monovalent measles vaccine is not required. Catch up vaccination with two doses of the vaccine should be given to all those not previously immunized (with no upward age limit) and especially to health care workers, adolescent girls and students travelling for studies overseas. All the currently licensed preparations of MMR vaccine are safe and effective and any one may be used. |
Several combinations for protection against measles, mumps and rubella are available. These include monovalent measles, mumps and rubella vaccines, MR vaccine and MMR vaccine. Monovalent mumps and MR vaccines are not available in India.
Rubella per se is a mild exanthematous illness; but if acquired in the first trimester of pregnancy can lead to disastrous consequences in the fetus/new born such as abortion, stillbirth, mental retardation, congenital heart disease, blindness and cataract. Hence the objective of vaccination against rubella is protection against congenital rubella syndrome (CRS).
Developed countries have remarkably reduced the burden of CRS by universal immunization against rubella. It is essential that when immunization against rubella is instituted more than 80% coverage is achieved. Haphazard use of rubella vaccine (monovalent or as a constituent of MMR) in young children through public health measure with sub-optimal coverage of the target population may be counter-productive as it may shift the epidemiology of rubella to the right with more clinical cases occurring in young adults leading to paradoxical increase in cases of CRS. This has been shown to occur using mathematical models. Direct evidence from some Latin American countries and Greece also corroborates these concerns.
There is paucity of reliable data on occurrence of CRS in India. Other developing countries have incidence rates of 0.6-4.1 per 1000 live births. WHO estimates that 100,000 cases of CRS occur in developing countries alone. Cost benefit studies in countries with routine immunization coverage over 80% show that benefits of rubella vaccine outweigh the costs particularly when combined with measles vaccination.
Rubella vaccine currently derived from RA 27/3 vaccine strain grown in human diploid/chick embryo cell cultures. The vaccine is available in freeze dried form that should be stored frozen or at 2 to 8 C and needs to be reconstituted with sterile diluent prior to use. The reconstituted vaccine must be protected from light, stored at 2 to 8 C and used within 6 hours of reconstitution. The dose is 0.5 ml subcutaneously.
A single dose of vaccine provides lifelong protection in 95% of the vaccinees. Apart from local side effects, a mild rash may develop in 5% of the vaccinees. Joint symptoms such as arthralgia and arthritis may occur 1-3 weeks following vaccination especially in susceptible post pubertal females but is usually mild. Immune thrombocytopenic purpura may occur in a frequency of 1 per 30,000 vaccinated children.
The vaccine is contraindicated in the severely immunocompromised and in pregnancy. Pregnancy should be avoided for 3 months after vaccination but babies born to women inadvertently vaccinated in pregnancy do not exhibit an increased risk of congenital malformations. Hence accidental vaccination in pregnancy is not an indication for medical termination of pregnancy.
Globally, most countries use MMR vaccine instead of monovalent vaccines. The epidemiology of measles and rubella has been discussed earlier. Mumps is a mild disease in childhood but can occasionally result in complications such as deafness, meningoencephalitis and orchitis. The burden of mumps has been reduced in developed countries following use of MMR vaccines. Like rubella, haphazard use of mumps vaccine can result in shift of epidemiology to the right and an increase in infection rates in adolescents and adults with greater complications.
Formulations from different manufacturers have different strains of the vaccine virus. Measles and Rubella strains have been discussed earlier. Mumps vaccine virus strains include Leningrad-Zagreb, Leningrad-3, Jeryl Lynn, RIT 4385 or Urabe AM9 strains and are grown in chick embryo/human diploid cell cultures. MMR vaccines are supplied in lyophilized form and should be frozen for long-term storage. In the clinic these vaccines can be stored at 2 to 8 C. The vaccines should be protected from light. Reconstituted vaccine should be stored at 2 to 8C, protected from light and used within 4-6 hours. The dose is 0.5 ml subcutaneously. The vaccine can be given along with all other childhood vaccines except BCG vaccine.
The immunogenicity and efficacy against measles and rubella has been discussed earlier. Seroconversion rates against mumps are more than 90% but clinical efficacy and long term protection against mumps with single dose is 60-90%; outbreaks have been noted in previously vaccinated populations. Hence two doses are needed for durable protection.
Adverse effects due to measles and rubella components have been discussed earlier. Five percent of children can get fever more than 39C, 7-12 days following vaccination and febrile seizures may occur. Aseptic meningitis can rarely occur 2-3 weeks following vaccination but is usually mild. Transient parotitis may occur. The virus does not spread from vaccinee to contacts.
There is now
incontrovertible evidence that there is no causal relationship
between MMR vaccine and autism, inflammatory bowel disease,
GBS and many other neurological complications. MMR is
contraindicated in patients with severe immunodeficiency,
pregnancy and those with history of serious allergy to vaccine
or its components. The vaccine should be given with caution
after weighing risks versus benefits in patients with history of
thrombocytopenic purpura and should be preferably avoided
in those were thrombocytopenia followed previous vaccination
with measles/MMR. The vaccine may be safely given in those
with history of egg allergy.