What are the symptoms of swine flu?
A temperature of 38°C (100.4°F) or higher, which comes on suddenly, combined with two or more of the following: sudden cough, headache, tiredness, chills, aching limbs and joints, muscular aches, diarrhoea, sore throat, running nose, sneezing or a loss of appetite.
"There is very little bog standard seasonal flu around at the moment, so if you have the above symptoms, it is most likely to be swine flu," says Dr Maureen Baker of the Royal College of General Practitioners.
Should you go to A&E, to your doctor or stay at home?
If swine flu is confirmed as a phone diagnosis, then you will be given an authorisation voucher. This means someone who can act as your "flu friend" can collect it from your GP's surgery and take it to a chemist to pick up Tamiflu (or the alternative anti-viral Relenza if you cannot take Tamiflu, for example, because you are pregnant).
"Avoid going to your GP's surgery. There may be people in the waiting room with underlying health issues for whom swine flu could be very dangerous," says Dr Baker.
The incubation period between infection and symptoms is about four days. "You will be infectious for around five days in all, from a day before symptoms begin, and while the symptoms are at their worst," says John Oxford, Professor of Virology at St Barts and the Royal London Hospital.
Can you take vitamins to stop yourself getting swine flu?
"The only way to reduce your risk of developing this illness is by practising good hygiene," says Professor Oxford.
"The virus can live around 24 hours on surfaces, so regular hand washing and daily cleaning of door handles and other surfaces with a standard cleaner is key."
There is no evidence that taking vitamins or supplements will help.
Do we have enough Tamiflu?
At the moment, yes, according to the Department of Health, which has enough to treat 50 per cent of the population.
The Government is going to increase that stockpile from 23 million to 50 million courses of the tablets but it's unclear when that supply will arrive.
Should you take Tamiflu if you don't have swine flu?
Tamiflu only halts the progression of swine flu. It does not kill the virus, but prevents it from replicating and so spreading the infection in the body. It can also act as a preventative.
"What it does is put a coating around the cells in your airways, throat and nose," says Professor Oxford. "This acts like a glass wall and prevents the virus from infecting the cells there.
"The effects of the Tamiflu will be pretty instant. However, each pill provides only a day's protection. Hypothetically, you could take a pill each day for the duration of this latest outbreak, but the effects of doing this have not been tested in the laboratory.
Furthermore, it is no longer Government policy to hand it out as a wide-scale preventative drug. The early stage of the swine flu outbreak was deemed the containment phase, when it was hoped the spread of the disease could be minimised and anti-viral medication was being given as a preventative measure.
Then, after July 2, this changed when the outbreak was deemed a treatment phase. This means swine flu is so widespread it is no longer containable.
"As the virus is more widespread now, there is no point giving Tamiflu as a preventative measure as so many people can now easily come into contact with someone infected with swine flu," says the Health Protection Agency.
Does Tamiflu have any side effects?
It causes nausea in one in 10 of us. It is also not suitable for pregnant women or those with kidney disease. Possible but rare side effects include skin reactions and symptoms of an allergic reaction.
"The key is not to take it on an empty stomach – we don't know why exactly, but having a dry biscuit or something else to eat just before you take it seems to prevent the nausea in most cases," says Professor Oxford.
Does Tamiflu work on ordinary flu?
Yes and no. "There are many, many different strains of flu," says Dr Baker. "Whereas the majority probably will respond to Tamiflu, others will not but those may respond to other types of anti-viral medication."
Can you buy Tamiflu online, and is it safe to do so?
Yes, but be careful. Around four per cent of spam emails offer Tamiflu and Relenza but there is no guarantee that they are genuine.
Those most at risk of complications include the over 65s, pregnant women and people with chronic conditions such as heart or lung disease.
Could swine flu became resistant to Tamiflu?
Yes, it can do. "There is always a risk that a virus will become resistant to an anti-viral medication," says Professor Oxford. "How long that takes varies; sometimes it never happens at all. However, the good news is that if a medication-resistant virus does mutate then for some reason it becomes less infectious and harder to spread from person to person. Only three people around the world with swine flu have been found to be resistant to Tamiflu treatment.
What happens if the swine flu virus mutates?
If it mutates, there is a possibility that the virus will become resistant to Tamiflu, in which case Relenza, the alternative anti-viral treatment, would be used instead.
Should you take Tamiflu on holiday?
Now that Tamiflu is not widely available as a preventative measure, it is unlikely that you would be able to get hold of a supply to take away with you, unless your GP agreed you were in a high-risk group and needed it.
"If you develop symptoms while abroad, seek medical advice locally," says the Health Protection Agency.
Do not attempt to travel if you do have the symptoms, as in many international airports there are now heat-sensitive cameras which can detect people with a high temperature.
When will there be a vaccine?
The first batch of the vaccine will be available by late August or early September. However, the truth is that scientists have not finished developing it yet. When it does come, it will be necessary to give everybody two jabs.
The Government has initially ordered only 60 million doses – so if everyone does need two doses there will not be enough to go round.
"It would seem sensible that those at risk, such as people with underlying chest problems, pregnant women and possibly health care workers will receive the vaccine first," says the Department of Health.
The next batch of the vaccine would not be available until towards the end of the year, traditionally when the flu season peaks.
The traditional winter flu jab offers 70-80 per cent protection and a swine flu vaccine should offer a similar level.
