Expectant mothers and people over 75 are being urged to get vaccinated against a potentially deadly virus following a record number of cases in Australia.
Health chiefs say the Australian winter often predicts how viruses will spread in the UK, and already this year cases of respiratory syncytial virus (RSV) have steadily risen in many areas.
The virus, which is a common cause of coughs and colds, may also cause a chest infection called bronchiolitis.
Some people have a high risk of becoming seriously ill with it, including babies and adults over 75.
According to NHS England, RSV is a leading cause of infant deaths worldwide and a main cause of children being taken into hospital.
Last winter, almost 7,000 bed days in England were taken up by children with RSV.
NHS England is encouraging pregnant women to get a jab that protects against RSV so their babies are protected after birth.
Kate Brintworth, chief midwifery officer for NHS England, said: “While for most adults RSV only causes mild, cold-like symptoms, for older adults and young children it can lead to serious breathing problems that can end up in hospitalisation.
“Getting vaccinated while pregnant is the best way to protect your baby from the moment they are born, and now is the time for mums to act, to make sure their babies are protected ahead of their first few months this winter, when there tends to be more bugs circulating.”
Yusra Osman says that when her son, Zakariya, was three months old, he developed bronchiolitis from the virus. He had a fever and was gasping for breath.
The 34-year-old, from north London, said: “Everything was a blur, but I remember his chest was caving in and out and he was really struggling to catch his breath.”
Nurses found her son’s oxygen levels were dangerously low.
Ms Osman, a student midwife, said: “That was one of those things you don’t want to hear as a mum. He was crying, and we kept trying to put an oxygen mask on, but he was fighting to get it off and didn’t want to be touched.”
Zakariya, who is now seven, needed oxygen and a feeding tube in hospital.
“It’s a mum’s worst nightmare. Had the RSV vaccine been available then, I’d definitely have had it,” Ms Osman said.
The RSV vaccine was offered to pregnant women in England for the first time last September and health officials say it has since helped to protect more than 300,000 mothers and babies.
Pregnant mothers from 28 weeks onwards are eligible, as are adults aged 75 to 79.
In the coming weeks, NHS England is set to invite more than a million people to have a jab, before the season for infections, which starts in October.
Greta Hayward, consultant midwife at the UK Health Security Agency, said babies born in late summer or the autumn are most likely to be admitted to hospital with the virus.
“Hundreds of babies attend emergency departments each day for bronchiolitis through most of November and December,” she said.