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The sound of a baby struggling for breath with whooping cough is as distressing as it is distinctive. A hacking cough is often followed by silence and then the long "whoop" as they are finally able to breathe in.

It is what happened to Katie Lodge from Weston-super-Mare just before she was due her first immunisation. She ended up on oxygen in hospital. You can hear her parents talking about her illness in the above video.

The surge in cases of whooping cough, or pertussis, is largely among adolescents and adults. They tend to have a less severe illness (although it can still be debilitating).

But this surge means more babies are at risk of the bacterial infection - five have died this year.

Babies are not fully protected until their third dose of vaccine at four months. Children get a pre-school booster. Vaccination coverage is high but immunity gradually wanes.

So far in 2012 there've been 2,398 cases of the bacterial infection in the UK, compared with just 272 in the same period last year.

Why have cases of whooping cough shot up? No-one is sure why; better testing and increased surveillance explain part but not all of the rise.

The Joint Committee on Vaccination and Immunisation - whose recommendations apply across the UK - has been considering how to deal with the resurgence of whooping cough.

One option is a booster dose in adolescence. Adam Finn, a professor of paediatrics at the University of Bristol, agrees that a new strategy is required.

He told me: "Giving a booster to adolescents is one thing that might help, but other things being considered are immunising parents of newborn babies, pregnant women or health care workers."

For Katie's parents, Claire and Jon Lodge, her illness was a frightening time. They hope to raise awareness of the infection and the importance of getting babies immunised promptly, so that they're protected as early as possible.