Caitlin is a firm believer in the importance of immunisation to protect children from harmful and deadly diseases.
Unfortunately the Victorian mum has no choice but to hope other parents feel the same way and get their children vaccinated, which will in turn keep her own son safe.
Caitlin's six-month-old boy Sonny has a rare genetic condition which means he can't receive any vaccinations.
"My dad has a rare immune deficiency disorder known as X-Linked Agammaglobulinemia (XLA), which is genetically transmitted," she told Essential Baby.
"We knew in my pregnancy that if I had a boy, there would be a 50 per cent chance of him contracting it as well. Even though we knew of the high probability, we were hoping that it wouldn't happen to us."
XLA prevents Sonny from producing B cells required to make antibodies - and those antibodies are necessary to fight off disease.
Because Sonny's immune system isn't operating efficiently, he is unable to receive vaccinations. It is also harder for him to fight off sickness when he does fall ill.
Caitlin and husband Liam were told of Sonny's condition when their baby boy was just three days old.
"My immediate fears were how would Sonny ever be protected, how would he go to kinder, how would he play with other kids?" Caitlin said.
"Sonny can never be immunised throughout his life. If he were to have an immunisation, it wouldn't have any effect due to the lack of antibodies to make the vaccines work.
"I am constantly worried about Sonny interacting with other kids, but I can't stop him from doing so as he grows older and gets more active. I try to keep him protected by keeping his toys separate from those of other kids, but this is often difficult and sometimes beyond my control as Sonny will soon be attending childcare and interacting with other kids.
"We often bring our own toys to events so that toys don't mix, and we're always conscious of sanitising play-mats, hands and everything in between to eliminate any bacteria as much as possible."
Sonny receives plasma infusions once every week to help him produce antibodies, but this treatment can leave him feeling unwell for up to 24 hours. The infusions aim to help reduce the severity of an infection but Sonny is still vulnerable to contracting illnesses.
While Caitlin and Liam do their best to keep their son infection-free, they can only hope that herd immunity resulting from the vaccination of his peers provides him with protection.
Caitlin describes vaccination as a "gift" and pleads with other parents to think about children like Sonny when deciding to immunise their own children.
She is supporting the Victorian Government's Immunity for Community campaign which highlights the benefits of immunisation for individuals and the community.
Currently 93 per cent of Victorian children under five are fully vaccinated, but this figure needs to reach 95 per cent to halt the spread of dangerous diseases.
Immunity for the Community is being launched this week to coincide with World Immunisation Week.
"We feel strongly about immunisation because if Sonny does come in contact with a vaccine-preventable disease, it could potentially be fatal for him," Caitlin said.
"It only takes a few uninformed people out there that don't vaccinate their children to potentially impact the lives of people like Sonny who have less immunity than the average healthy person.
"People often don't consider what impact vaccination can have on others around them. By immunising your children you can help protect those who can't be vaccinated, such as children who are too young to receive immunisations, or those who can't be vaccinated due to medical conditions, such as our little Sonny.
"It's that age-old saying that it takes a community to raise a child."