A Brisbane mum who posted a video of her baby boy battling whooping cough claims to have been attacked online by anti-vaccination campaigners.

Rebecca Harreman’s video on Facebook of her four-month-old son, Austin, struggling to breathe during a whooping cough attack has been viewed more than a million times since she posted it on the weekend. The video was accompanied by a 400-word post in support of vaccination.

Since posting it, she says she has been bombarded with hateful private messages from anti-vaxxers.

“For those of you sitting on the fence on whether to vaccinate yourself and your kids or not… maybe this video will convince you,” Ms Harreman wrote in her original post.

“I don’t care whether you want to try and prove to me that vaccinations and herd immunities don’t work.

“I don’t care that vaccinations have side effects, because every person in this world reacts differently to all types of food, products and medicines. I could not care less, even if it is ever proven one day that they don’t work.

“You know why? Because at least at the end of the day I tried to do something to prevent this and not sit there and say ‘oh well, vaccinations don’t work so I’ll just sit here and do nothing’… because doing nothing goes against every cell in my body as a mother. Doing nothing is just wrong.

“So please share this and spread some awareness… not nonsense. This is getting worse because people are not vaccinating!”

In a follow-up post, Ms Harreman wrote that she was overwhelmed by the response to her post, from both supporters and anti-vaxxers.

“I really didn’t think that people would personally message me to tell me I am wrong,” she wrote in a follow-up post.

“I didn’t intend to offend anyone in particular with my views. Because they are just that — MY views.

“But since some anti-vaxxers seem to feel they can share and say anything they want, even if it is unreliable, and I’m not allowed to have my say or share my own personal experience… well then I say bring it!

“No more turning a blind eye and not sharing opinions for fear it will upset someone else.

“It’s called freedom of speech. If they can say what they want, then so can I.”

Ms Harreman later wrote another Facebook post, before setting her account to private.

“Okay this is getting out of hand,” she wrote.

“I truly appreciate all the messages of love and support and well wishes from strangers all over the world. It’s incredible and truly meant a lot.

“I also appreciate all the questions coming in for those people fence sitting on whether or not to vaccinate — there are literally hundreds of them coming in.

“But I unfortunately don’t have time to respond to everyone’s messages, even though I’d really love to.

“Because as of this moment Austin is back in hospital and my inbox is packed to the brim, people are reporting my family portrait for nudity on FB and let’s not even start on what the anti-vaxxers are sending me.

“So I’m making this post another public one just to say thank you and it’s time for me to go private so I can just concentrate on my family, my son and his health.”

Ms Harreman’s posts coincided with Queensland Health issuing a whooping cough alert for Brisbane, as 10 children under the age of five have caught the potentially fatal infection in the past six weeks.

Metro South Health public health physician Dr Kari Jarvinen said the number of whooping cough cases in the Brisbane area has been relatively low for the past year or two, making this increase particularly concerning.

Dr Jarvinen said vaccination is the only effective way to minimise the risk of whooping cough, with most hospitalisations and deaths occurring in babies less than six months old.

Since immunity to whooping cough is not lifelong, Queensland Health is urging everybody who has contact with small children to stay up to date with their vaccinations or risk passing it on.

For more information on whooping cough, visit conditions.health.qld.gov.au. For more information on vaccinations, visit vaccinate.initiatives.qld.gov.au.