Measles

 causative agent the measles virus belong to the genus morbillivirus which is a member of the family paramyxoviridae

Vaccines against measles : live attenuated measles vaccine was first introduced for widespread use in 1963 .The primary strategy has been to achieve a high level of immunity in early childhood via mass vaccination campaigns

Vaccine strains

All vaccine strains that are currently in use (except Leningrad-16) have been derived from Edmonston strain .

Measles virus strains being used to prepare vaccine Edmonston A,Edmonston B ,Enders, Schwarz ,and Edmonston –Zagreb .

Edmonston –Zagreb strain has been adapted for growth on human diploid cells (WI-38) thus not only attenuating it further but also making it suitable for better and large scale industrial production ,many studies have shown higher seroconversion rates with these vaccines in younger infants (4-6 months) even those with higher material antibodies titre this makes these vaccines superior to the already available vaccine using Edmonston or Schwarz strain .

Composition of vaccine

The minimum quantity of the vaccine virus that should be contained in one human dose is generally considered to be 1000 viral infection unit .the minimum dose has been set at 5000 infective units .the vaccine is available as freeze dried product with a diluents

Dose and route of administration

It is administered as a single dose of 0.5 ml either alone or incombination with rubella and mumps components which is inoculated either intramusculary or deep subcutaneously

Contraindications

a-acute febrile illness

b-within three weeks of administered of another live virus vaccine but may be administered simultaneously and at different site  .

c- immunodeficiencies and malignancy d- pregnancy

Adverse reactions 

Sever reactions to measles vaccine are rare ,minor local reactions ,slight fever or rash may occur after measles vaccine these occur 5-10 days after vaccination in about 5-10 % of children receiving the vaccine

Mumps

Causative agent mump virus is amember of the family paramyxoviridae

Composition of vaccine

Mump vaccine is being prepared with any of the following live attenuated strains (Jerly Lynn, Leningrad ,Urabe ,Rubini ) the vaccine contains 5000 CCID 50 (cell culture infective dose ) of the virus in each dose of vaccine .the vaccine is available as mump a lone or more commonly in combination with measles and rubella vaccine (MMR vaccine ) whether alone or in combined presentation of MMR the viral content remains same .

The Jerly Lynn strain which grown in chick embryo cell culture had been given to nearly 100 million children and adult through the world ,whether used singly or in combined with measles and rubella vaccines .Vaccines based on Leningrad -3 strain of attenuated mump virus were produced in cell culture of Japanese Quail embryo and chick embryo cell culture more than 25  million doses of vaccines based on this strain have been used as monovalent or combination with measles and rubella vaccine .the Urabe strain of attenuated live mump virus was produced either in amnion of embryonated hen s egg or in chick embryo cell culture ,more than 10 million persons had been immunized with urabe strain in Japan and other countries used as monovalent or in combination with measles and rubella

Dose and route of administered as with measles vaccine

Efficacy

The live attenuated mump vaccines have been given to million of people throughout the world .Although always at lower level the ab after vaccination rises and falls a level parallel to that after natural infection .the exact duration of protection is not known but is probably long ,lasting .In some studies satisfactory ab level have been seen in period exceeding ten years .Duration of protection is extremely important in mumps since there is no point in protecting a young children against mump with orchitis as an adolescent or adult .the Public Health serves Avisory committee on immunization practices recommends that live mump vaccine given to children after 12 months of age and others known to be susceptible or who have not had mump .

Contraindication

     1-acute febrile illness 2-immunodeficiencies and malignancy

 3- sever sensitivity to egg or chicken protein and to antibiotic present in vaccine (eg neomycin ) 4- children under one year of age because they may retain maternal mump neutralizing ab which may interfere with the immune response 5- pregnancy and three months before conception

Adverse reaction

Complication with mump vaccine have been rare .these include haemolytic uraemic syndrome ,possible deafness encephalopathy

Local reaction ,swelling ,redness and pain .general reactions such as fever ,urticaria and parotid’s in less than 1% of recipients

Rubella 

Also known as German measles

Causative agent Rubella virus is a member of genus rubivirus which is non arthropod borne virus to family Togaviridae..

Vaccine against rubella composition

Live attenuated rubella vaccine is a available as freeze dried preparations .Almost all the commercially produced vaccines no a days are derived from RA-27 /  3 vaccine strain. The virus content is not be less than 1000 CCID 50 or 1000 PFU per human dose .The vaccine is stored at all times at a temperature below 8 C

Dose and route of administration

Single dose is 0.5 ml which is re constituted with diluent provided with freeze dried vaccine .The MMR vaccine also contains equal amount of rubella virus as is present in rubella monovalent vaccine .the vaccine is injected subcutaneously or intramuscularly in the upper arm .

The anti- D immunoglobulin doesn’t interfere with ab response to rubella vaccine which may be given at the same time as anti D immunoglobulin but in different sites and with separate syringes

Age for immunization

For many years ,the USA and Europe differed in their approaches to the use of rubella vaccine .In USA the vaccination of both preschool boys and preschool girls was recommended while in Europe recommended the immunization of only prepubertal girls aged 11-13 years

Rubella vaccine and fetus

   Women who reach child bearing age with no immunity to rubella must be protected by vaccination against contracting the disease before they become pregnant .The women is not already in the early weeks of pregnancy .She must be advised to avoid pregnancy for at least three months after vaccination .the vaccine virus is capable of crossing the placenta and has been isolated from aborted fetal tissue including the eye, kidney and bone marrow  .Whether the vaccine virus can damage fetal tissue as does will virus is not clear ,it may be that ,though well attenuated for adult tissue ,it may  prove less attenuated  for fetal tissue .or possibly it may be merely a matter of dosage if enough vaccine virus gets through it may cause damage changes in the placenta ,deciduas and fetal eye caused by vaccine is similar to those in congenital rubella but so far no defects have been found in full term infants born of women inadvertently given vaccine during their pregnancy

Adverse reactions

Local reactions swelling ,redness and pain ,general mild reaction  such as lymphadenopathy ,fever, sore throat ,malaise ,headache usually occur 1-3 weeks after vaccination

Contraindication

1-acute febrile illness 2-immunodeficiencies and malignancy

3- pregnancy and three months before conception