UK swine flu cases have fallen for the first time since August, down to 64,000 new infections in the past week. It is thought the half-term break may be behind the drop of 20,000 from the previous week.

Despite a fall in cases the number of people needing hospital treatment for the virus has remained high, with 785 patients in hospital. Of these patients 173 are receiving critical care.

The UK has also seen 28 further deaths related to swine flu, raising the total to 182: 124 in England, 33 in Scotland 14 in Wales and 11 in Northern Ireland.

VACCINATIONS Virtually all GPs have now received their first supplies of the swine flu vaccine. The 6.6 million doses delivered in the past month are now being used to protect those most susceptible to swine flu, including pregnant women and people with long-term conditions.

The government is also launching an advertising campaign that will explain the importance of receiving the vaccine, which is expected to offer several years of protection against swine flu.

OTHER SWINE FLU NEWS Use of the National Pandemic Flu Service has levelled off.

Priority groups continue to be vaccinated, and virtually all GPs have received their first delivery of swine flu vaccine.

The Department of Health has published new guidelines for the treatment of swine flu in pregnancy. The new guidance contains detailed advice for clinicians caring for pregnant women. Also available is a leaflet for pregnant women.

VACCINATION PROGRAMME NHS hospitals are now vaccinating patients facing the greatest risk of complications. Healthcare staff dealing with the public are also being vaccinated to help keep medical services running smoothly and to prevent them from passing the virus to patients.

Virtually all GPs have received their first supplies of the vaccine. Patients will be contacted by their GPs if they fall into one of the at-risk categories.

The order of priority will be: People aged from six months to 65 years in current seasonal flu risk groups All pregnant women Those living with people with compromised immune systems, for example those recieving cancer treatment People aged over 65 in the current seasonal flu risk groups.

The government has produced a swine flu vaccination leaflet with more information. The chief medical officer, Sir Liam Donaldson, said: "I urge everyone in the priority groups to have the vaccine - it will help prevent people in clinical risk groups from getting swine flu and the complications that may arise from it."

PRIORITY CATEGORIES Who is a priority for vaccination with the H1N1 swine flu vaccine?

People who are most at risk from swine flu need to be vaccinated first. These groups are, in order of priority: People aged between six months and 65 years in the seasonal flu vaccine at-risk groups.

All pregnant women, subject to licensing. The European Medicines Agency, who license the vaccine, will indicate whether it can be given to all pregnant women or whether it should only be offered at certain stages of pregnancy.

People who live with those whose immune systems are compromised, such as cancer patients or people with HIV/AIDS.

People aged 65 and over in the seasonal flu vaccine at-risk groups.

Frontline health and social care workers will also be offered the vaccine at the same time as the first clinical at-risk groups. Health and social care workers are both at an increased risk of catching swine flu and of spreading it to other at-risk patients.

AT RISK GROUPS What are the seasonal flu vaccine at-risk groups?

These are people with: chronic respiratory disease, such as chronic obstructive pulmonary disease (COPD), chronic heart disease, such as heart failure, chronic kidney disease, such as kidney failure, chronic liver disease, such as chronic hepatitis, chronic neurological disease, such as Parkinson's disease, diabetes requiring insulin or oral hypoglycaemic drugs, and immunosuppression (a suppressed immune system), due to disease or treatment.

Why are healthy people over 65 and children not a priority for the swine flu vaccine?

Healthy people aged over 65 appear to have some natural immunity to the swine flu virus. And while children are disproportionately affected by swine flu, the vast majority make a full recovery - therefore the experts do not advise that children (other than those in at-risk groups) should be vaccinated initially.

REVISED ASSUMPTIONS Revised planning assumptions It was announced on September 3 that estimates of deaths in the worst-case scenario for swine flu have been lowered. The government's expert advisers on swine flu, the Scientific Advisory Group for Emergencies (SAGE), said that new data from the UK, north America, Australia and elsewhere give a better picture of how the virus might spread in the autumn.

The revised planning assumptions have cut the estimated death toll in a worst-case scenario from 65,000 people in the UK to 19,000, assuming that 30% of the population is infected.

These forecasts and others in the report are based on a "reasonable worst case" value and should not be taken as a prediction of how the pandemic will develop. Planning against the reasonable worst-case scenario will ensure, however, that plans for all likely scenarios are robust.

The Department of Health said: “In light of this new information, the estimates for the number of people who might need hospitalisation and the proportion of people with swine flu who could die have been reduced.”

Vaccination should cut hospitalisation These new planning assumptions do not take account of the vaccination programme which, once it has begun, will help to further reduce the number of people needing hospitalisation. However, the department added, we must not be complacent. While in the majority of people it is mild, for some this virus can be a serious illness.

Who is at greatest risk of serious complications from swine flu?

Some people are more at risk of complications if they catch swine flu, and need to start taking antivirals as soon as it is confirmed that they have the illness. Doctors may advise some high-risk patients to take antivirals before they have symptoms, if someone close to them has swine flu.

It is already known that people are particularly vulnerable if they have: chronic (long-term) lung disease, chronic heart disease, chronic kidney disease, chronic liver disease, chronic neurological disease (neurological disorders include motor neurone disease, multiple sclerosis and Parkinson's disease), immunosuppression (whether caused by disease or treatment), or diabetes mellitus.

Also at risk are: patients who have had drug treatment for asthma in the past three years, pregnant women, people aged 65 and over, and children under five.

National Pandemic Flu Service The National Pandemic Flu Service was launched in July. This online service assesses patients for swine flu and, if required, gives them an authorisation number that can be used to collect antiviral medication.

The system, which can also be accessed by phone, will take the strain off GPs as swine flu spreads. For the moment, it is being used only in England.

“The National Pandemic Flu Service is a new self-care service which will give people with pandemic swine flu symptoms fast access to information and antivirals,” said a Department of Health spokesman.

“This new service will free up GPs, enabling them to deal with other illnesses that need their urgent attention.”

The launch of the system brought important changes to the official advice that is given to people who think they may have swine flu. That advice – and the new system – is supported by the Royal College of General Practitioners.

Swine flu medicines To learn about the medicines used to treat pandemic flu, including the benefits and side-effects, go to the pandemic flu medicine guide.

Reporting side effects If you take an antiviral and have suspected side effects, first contact your GP to check that you are OK. You can then report your side effects on MHRA's new online system.

Advice for antivirals Several newspapers reported that the World Health Organization (WHO) had changed its advice regarding use of antivirals for swine flu. Its advice suggests that while antivirals should always be given in serious cases, they may not always be necessary for otherwise healthy people.

The papers pointed out that this appeared to differ from the approach taken in the UK, where Tamiflu is being widely used.

However, the Department of Health said: "We believe a safety-first approach of offering antivirals, when required, to everyone remains a sensible and responsible way forward. However, we will keep this policy under review as we learn more about the virus and its effects.

"The WHO recommendations are in fact in line with UK policy on antivirals. We have consistently said that many people with swine flu only get mild symptoms, and they may find bed rest and over-the-counter flu remedies work for them.”

For an explanation of swine flu, its symptoms and treatment, go to Swine flu A-Z For quick questions and answers go to Swine flu Q&A For information in other languages and formats go to Swine flu: other languages To check your symptoms go to the National Pandemic Flu Service For advice on how to protect yourself and your baby go to Swine flu and pregnancy Latest advice If you have flu-like symptoms and are concerned that you may have swine flu, the advice is to stay at home and check your symptoms at the National Pandemic Flu Service.

Patients with swine flu typically have a fever or a high temperature (over 38°C / 100.4°F) and two or more of the following symptoms: unusual tiredness, headache, runny nose, sore throat, shortness of breath or cough, loss of appetite, aching muscles, diarrhoea or vomiting Call your GP if: you have a serious underlying (existing) illness, you're pregnant, you have a sick child under one year old, your condition suddenly gets much worse, or your condition is still getting worse after seven days (five for a child).

For people who do not have internet access, the National Pandemic Flu Service can be accessed by phone on: Telephone: 0800 1 513 100 Minicom: 0800 1 513 200 For more information on the National Pandemic Flu Service, go to Flu Service: questions and answers.

People in Scotland, Wales and Northern Ireland can visit www.direct.gov.uk/pandemicflu Advice for pregnant women Pregnant women are one of the higher risk groups for swine flu, as they are for all influenza viruses. It is therefore important for them to take precautions.

This website provides full and up-to-date advice for pregnant women and parents of young children. The advice has not changed recently and is available at the following links: Swine flu advice for pregnant women.

Swine flu pregnancy and parenting Q&A.

Swine flu symptoms, including high-risk groups.

Chief medical officer's advice on pregnancy, holidays, and parents.

How dangerous is swine flu?

The vast majority of cases reported so far in this country have been mild. Only a small number have led to serious illness, and these have frequently been where patients have had underlying health problems.

Reduce the risk of catching or spreading flu Cover your mouth and nose when coughing or sneezing. Use a tissue.

Dispose of used tissues carefully.

Wash your hands frequently with soap and water or alcoholic hand rub.

Clean hard surfaces (e.g. kitchen worktops, door handles) frequently using a normal cleaning product.

There has been an argument put forward that the government should restrict antivirals to those groups who are most at risk of developing serious complications from swine flu. In other words, if people are otherwise healthy, then the NHS should let the virus run its course, treating it with paracetamol and bed rest, as for normal flu.

However, the government’s Scientific Advisory Group for Emergencies (SAGE) believes there is still some uncertainty about the risk profile of the virus. For instance, there are reports of some cases in Argentina where young, healthy adults have apparently become extremely ill from swine flu.

While there is still this doubt, the government has decided to continue offering Tamiflu to everyone with swine flu at their doctor's discretion.

"We will keep this matter under review, with advice from SAGE," said health minister Andy Burnham.

You can read the Department of Health's guide for further information on the science of swine flu treatment. Catch it, Bin it, Kill it Although the UK has moved to a treatment phase for swine flu, it’s important that people continue to do everything they can to stop the virus from spreading.

The most important way to stop it spreading is to have good respiratory hygiene (i.e. sneezing and coughing into a tissue) and hand hygiene (keeping your hands clean). The video Catch it, Bin It, Kill It explains the importance of catching your sneeze in a tissue, placing it quickly in a bin and washing your hands and surfaces regularly to kill the virus.