Amid fears New Zealand could see a spike in whooping cough cases, there are several symptoms parents can look out for in their children, including a child's tongue turning blue while coughing.
There have been two whooping cough deaths this year of babies under one, with doctors worrying New Zealand is on the brink of its worst whooping cough epidemic in years.
The Ministry of Health says symptoms usually appear around a week after infection due to the incubation period.
The first signs of the infection are similar to a cold, with a blocked or runny nose, sneezing, a mild fever and "persistent spasms of coughing". This is when people are most infectious.
The ministry says after about a week, children with whooping cough may have uncontrollable coughing fits that are worse at night time.
Parents may hear a "whoop" sound when their child is breathing between coughing fits, and they may bring up a mucus that can cause vomiting or choking.
The ministry says if your child has prolonged coughing spasms, their tongue turns blue while coughing, or are unvaccinated, they will need to see a doctor.
It said people should seek medical advice if they have a baby who is six months or younger and seems sick, are experiencing breathing difficulties, seizures, or symptoms of pneumonia.
"In babies whooping cough is very serious and may require hospitalisation," the ministry's website says.
Earlier this month Te Whatu Ora urged children and pregnant women to be immunised against whooping cough amid the two deaths.
It said early diagnosis and treatment with antibiotics can reduce infection time from five days to three days.
If left untreated, people can pass the illness on for up to three weeks.
Te Whatu Ora says anyone who is unwell with any sort of respiratory illness symptoms should not visit pregnant women or young babies.
Pregnant women can get a whooping cough vaccine from 16 weeks' gestation onwards - her immunity can be passed onto the baby, protecting them until they can be vaccinated themselves.
Babies then can be immunised at six weeks, three months and five months, with booster doses at four and 11.
At age 45, adults are eligible for combined tetanus, diphtheria and whooping cough vaccine if they have not previously received four doses of tetanus vaccine.
At age 65, adults are eligible for combined tetanus, diphtheria and whooping cough vaccine.
Other adults can pay for vaccination, which is recommended for those whose work brings them into regular contact with infants, or those who live or care for infants aged under 12 months, even if the baby is immunised.