Wanting to help children was one of the main reasons I became an epidemiologist specialising in vaccine safety and effectiveness. My PhD thesis investigated the epidemiology of whooping cough in children, but I never imagined how that academic pursuit would haunt me when I became pregnant a few years ago. I knew too much – things I wished I didn’t know, things that kept me awake at night.
During my daughter’s first six months, every cough felt like doom. I received the whooping cough vaccine during my second trimester, my partner received his booster shot, and I encouraged my family to get vaccinated as well. There was no outbreak then; it was a time of peace. Now, pregnant again amid the rise of a new whooping cough epidemic, I find myself sleepless once more, feeling powerless against the spectre of Bordetella pertussis (bacterium that causes whooping cough).
Dr Hannah Chisholm never imagined how her academic pursuit would haunt her when she became pregnant.
This epidemic might be the biggest, ugliest and most challenging in New Zealand history. The writing has been on the wall with disastrous childhood vaccination coverage, a lower level of immunity in the population because of low vaccination rates, social distancing measures, housing quality and high childhood poverty.
Talk to the doctors and nurses who care for the babies and they’ll echo the same sentiment: this disease is devastating because there’s no truly effective treatment. As one doctor put it( paraphrased) – during a coughing fit, all you can do is offer oxygen, sit the baby upright and hope for it to breathe again. Parents watch in helpless agony.
A similar haunting helplessness extends to scientists like me. We provide evidence for how things could improve, yet influencing policy is a slow business and almost as hard to achieve as reshaping the structure and function of the healthcare system. The gap between knowledge and action weighs heavily.
The best way to protect a baby from whooping cough is for the mother to get vaccinated during pregnancy (in New Zealand this is funded from 13 weeks). However, for some parents there are significant barriers to making this happen, such as limited time, no paid leave, lack of transport and childcare, and poor availability of vaccination appointments. Other issues stem from a lack of information or reassurance from maternity care providers.
It’s important to remember pregnancy is a stressful time. Many mothers become especially mindful of what they consume, and vaccines are no different. This heightened caution can contribute to hesitation, making clear, supportive communication from healthcare providers even more crucial.
Our healthcare system’s operation and the inadequate support for mothers to follow recommended advice, particularly during pregnancy, are beyond my control. But what I can do is try to reach a few individuals who are in the position to vaccinate but haven’t yet made their decision. My hope is to offer them some much-needed reassurance.
The whooping cough vaccine administered during pregnancy is very safe and effective. Photo / Getty Images
I want to convey the whooping cough vaccine administered during pregnancy is very safe and effective. And perhaps, alongside that information, I can provide a little comfort – a spoonful of chicken soup for a parent’s soul.
The currently offered whooping cough vaccine is minimally reactogenic (pretty safe). The most one normally gets is a bit of a sore arm. Indeed, it was created in response to an earlier version that was causing fevers in children, and while immunologically, this is not normally a bad thing, it was discouraging enough to reduce vaccine coverage at the time and trigger the development of a new vaccine.
The booster vaccine given during pregnancy is a low-dose version. New Zealand has safely used it since 2013 – initially as part of an outbreak response, and later routinely as part of the standard immunisation schedule.
Maternal vaccination is the best way to provide some immunological protection for babies in their first six weeks of life, when they are most susceptible to serious disease and before they are eligible to receive the vaccine themselves. Effectiveness estimates for maternal vaccination preventing whooping cough disease in newborns are between 70-95%.
Making decisions that balance risks and benefits is never easy, and I’ve found it even harder when the decision involves my child. A piece of wisdom once shared with me has always felt like chicken soup for the soul, helping me move forward. It came unexpectedly during a conversation with another mother. I had asked how she decided whether to vaccinate her child. Her response stuck with me: “Ultimately, I knew I could live better with my decision if I acted to protect my child – even if something went wrong – than if I chose not to act and they got sick.”
Whooping cough is a highly infectious disease, and while experts do not widely recognise the vaccine’s ability to significantly prevent transmission, growing evidence suggests it contributes to herd immunity. Immunity of our herd (community immunity) is what we need to curb this epidemic.
Family members or friends who are in contact with young babies, I urge you to consider getting a booster. The safety profile of this vaccine measured against the risk to vulnerable young babies exposed to Bordetella pertussis is far too great to ignore. As parents, we rely on our villages to help us raise happy, healthy children. Protecting them is a collective effort – we can’t do it alone.
New Zealand is facing a whooping cough epidemic that could see thousands of babies and toddlers catching the disease. Half of babies up to 12 months old who catch whooping cough need hospitalisation, and one or two in every 100 of those hospitalised will die. Vaccination is essential.
