PREGNANT women are to be vaccinated against whooping cough, health officials said, after the biggest outbreak of the illness for two decades claimed the lives of 10 babies.
So far this year 10 infants under the age of three months have died as a result of the infectious disease - including nine in England and one in Northern Ireland.
There have been 4,791 confirmed cases in England and Wales between January and August - four times more than the total figure for 2011, when there were 1,118 cases, the Health Protection Agency (HPA) said.
Chief Medical Officer Professor Dame Sally Davies, the Government's principal medical adviser, said that mothers-to-be will be offered the vaccination to protect their newborn babies.
Youngsters cannot receive the jab until they are two months old. Vaccinating their mothers before they are born will boost their immunity until they reach the age they can get the injection themselves, Dame Sally said.
From Monday, women across the UK who are between 28 and 38 weeks pregnant will be offered the vaccination.
Increases in whooping cough are usually seen every three to four years. The last rise in the number of confirmed cases was recorded in 2008.
The largest number of cases have been in those over the age of 15 but there has also been a sharp rise in whooping cough in babies aged under three months.
Between January and August there were 302 cases reported in babies under three months, compared with just 115 cases in the whole of 2011.
Prof Davies said: "Whooping cough is highly contagious and newborns are particularly vulnerable. It's vital that babies are protected from the day they are born - that's why we are offering the vaccine to all pregnant women.
"The idea is, because very young babies can't make an immune response - an antibody against the vaccine - we are going to give this vaccine to the mothers so they make an antibody against it which will travel across the placenta into the baby.
"This will protect the baby from whooping cough up to the time of the first immunisation at eight weeks."
However, the drug which is to be administered, called Repevax, comes with the recommendation: "Limited post-marketing information is available on the safety of administering Repevax to pregnant women. The use of this combined vaccine is not recommended in pregnancy".
But the Joint Committee on Vaccination and Immunisation (JCVI) - the independent panel of vaccine experts which advises the Government - said that it has "no concerns" about the safety of the vaccine, which protects against whooping cough, diphtheria, tetanus and polio.
Prof Davies added: "I know that pregnant women can feel very vulnerable about protecting themselves and their baby's health and clearly we don't want pregnant women taking medication of any form unless it's necessary. But I can't stress enough that this is an important thing that pregnant women can do to protect their baby."
The vaccine is similar to the one used in the same programme in the US. It will be administered through routine antenatal appointments with nurses, midwives or GPs.
The Department of Health's director of immunisation Professor David Salisbury said: "Over the last year we have seen a large rise in the number of whooping cough cases, with the most serious cases being in children too young to be protected by routine vaccinations.
"The vaccine that we are offering to pregnant women has been recommended by experts and a similar vaccine is already given to pregnant women in the US. If you are pregnant, getting vaccinated is the best way you can protect your baby against whooping cough."
While whooping cough can cause nasty symptoms in adults, it does not usually cause any long-lasting complications and can be treated with antibiotics.
In the very young, whooping cough can be a serious illness and can lead to death in some cases.
Babies and children can often make a distressing "whoop" sound while gasping for air after a coughing fit.
Older children and adults tend to suffer a prolonged cough.
The £10 million programme, which has only been set up on a temporary basis, has been given the seal of approval from the JCVI and a number of royal colleges.
Dr Mary Ramsay, head of immunisation at the HPA, added: "We have been very concerned about the continuing increase in whooping cough cases and related deaths.
"We welcome the urgent measure from the Department of Health to minimise the harm from whooping cough, particularly in young infants, and we encourage all pregnant women to ensure they receive the vaccination to give their baby the best protection against whooping cough.
"It's also important we continue to remind all parents to ensure their children are vaccinated against whooping cough to continue their protection through childhood."