Friday 19 July 2019

Dear Dr Nina: 'What's the risk to my sister's baby of catching the measles? She is currently breastfeeding'

Ask the Doctor

With Nina Byrnes

Babies normally get immunity from measles passed to them from their parents, but this immunity can wane over time
Babies normally get immunity from measles passed to them from their parents, but this immunity can wane over time

Q: My sister has just had a baby and lives abroad. She intended to travel back to Ireland as soon as she got her child's passport, but now she is terrified of her baby catching the measles due to all the media stories of people not vaccinating their children. I believe children are not vaccinated against measles until about one year. Is this true? Also, what are your thoughts on the actual risk to the baby of catching the measles? She is currently breastfeeding.

A: Measles cases are on the rise across the world and this is indeed something to be concerned about. There have been 1,548 cases reported across 22 European countries so far this year. Ireland accounts for 58 of these cases. Most of the cases are occurring in teenagers and adults. Only 14.3pc occurred in those under one year of age, but these unvaccinated children are at risk of serious infection and complications. One-in-four people infected with measles will require hospitalisation. Measles is highly contagious and a herd immunity of 95pc is considered ideal. In Ireland, so far we have had around a 92pc uptake of the measles vaccine. This is not bad, but we can do better.

There has been much debate recently about how best to achieve herd immunity in our population, but there is no doubt the best protection is vaccination. The evidence is very strong. There has been an 84pc drop in death from measles since 2000 with increasing vaccination uptake.

Measles is highly contagious and it's thought one infected person can infect 12-18 other people. Thankfully, immunity passes to the baby through the placenta. These antibodies protect a baby during pregnancy and after birth, providing passive immunity. It is strongest in the first month or so and then starts to wane, but some immunity lasts usually until about one year.

The MMR vaccine is given to babies at one year of age. The reason this age is chosen is it is a live vaccine and our bodies respond best to these after about one year of age. The second MMR vaccine is given in junior infants in school at around age four. About 85pc of children are immune after one vaccine dose and it is felt that about 99pc of people are immune after two doses.

MMR vaccine can be given from six months of age, but as this immunity can wane, the child still needs two further doses at one and four years of age.

Early vaccination is recommended for those travelling to areas where measles has been reported. It has been suggested that giving earlier doses to those travelling to higher-risk countries such as France, Romania, Poland, Lithuania, Bulgaria and Germany may be advantageous.

The HSE has not recommended earlier vaccination in Ireland related to the recent outbreak and unless you have been directly or inadvertently exposed to one of the cases, no new procedures are in place. Measles is a notifiable disease and public health doctors actively track those infected and their contacts. Thankfully, it sounds like your sister is passing some of her immunity to her baby and that is the best protection she can offer. In an ideal world, we would achieve full herd immunity and thus declare our country measles free, but the debate about compulsory vaccination rolls on, making this harder to achieve.

Irish Independent

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