The extra dose of MR vaccine in campaign is not meant for the direct personal protection of your child, It is an eradication drive against Measles and Rubella and is in addition to the routine MMR doses given to your child.
The principle is that if large no of doses are given during a short time ie a same day or few days consecutively, it breaks the person to person communication of viruses and so can result in eradication.... like it was done in case of small pox in 1970s. So, indirectly yes, your child does get benefited if the whole community is disease free permanently and if that happens like it happened in case of small pox eradication, then future generations would need even lesser vaccines.
So, getting this for your child is out of your duty as a dutiful citizen to participate in the national drive against MR. These doses are in addition to the routine doses of MMR vacicen which your child has recieved.
Do vaccines used in campaigns have more side effects ?
We often hear news about side effects of rash, fever, shivers, etc whenever vaccines are given in large groups of children...
It is not unsusal and should not worry and its is best understood as..... for eg.. if we give MMR vaccine to 100 kids, we are bound to get some reaction like a rash or fever in 10-20% cases and severe rash or reaction in about 5% cases,
In campaigns, a large group gets the vaccine from a single batch of vaccine so you keep on hearing such news, whereas in a personal practice or clinic, we will be taking a full year to give 100MMR doses and every few weeks the batch would be different, so practically we wont hear of any side effects in a routine clinic practice, but when the volumes go high as in a campaign like this, you are bound to get clustered reports of side effects, due to a same batch being used for a same big group eg a class of 50, but if you calculate the over all chance of risk, the percentages would be less, as mentioned above.
So these vaccines do not have any different side effects from the routine vaccines which all children take, right from their birth.