|Updates / News
24th December 2010
H1N1 winter flu: Urgent advice for providers of maternity services
Severe illness in pregnant women is increasing. Vaccination now will protect pregnant women and new babies this winter.
Influenza H1N1 (2009) which caused the recent pandemic remains common among circulating flu viruses. Over the last two or three weeks influenza activity in the UK has been increasing and GP consultation rates are now above baseline in England. Eighty-eight community outbreaks of acute respiratory disease have been reported across England. An increasing number of severe cases of influenza are being reported – many requiring admission to intensive care and, in some instances, Extracorporeal Membrane Oxygenation (ECMO) services. All of those requiring ECMO are under 60 years of age and some of these cases are in pregnant or post partum women. Seventeen deaths in the UK have so far been associated with the H1N1 (2009) strain – the majority are under 65 and unvaccinated.
The influenza A H1N1 (2009) and B are the predominant viruses. The H1N1 (2009) virus is virologically and epidemiologically similar to that seen during the pandemic. There remains a close match between the 2010/11 seasonal vaccine and circulating strains. The Health Protection Agency expects to see continued, elevated influenza activity for several weeks.
Pregnant women are considered a high-risk group for severe influenza infection caused by the H1N1 (2009) virus.
In the current influenza season, pregnant women are likely to be exposed to this virus, with a risk of severe or complicated disease. Pregnant women are now well-recognised as being at significantly increased risk of complications, including death, from H1N1 (2009) influenza infection. They are at greater risk of hospitalisation and currently a number of pregnant women are in intensive care or receiving ECMO. The mortality rate is several times higher than that for non-pregnant women in the same age group. The greatest risk is of severe chest infection, due to the flu itself, or to secondary bacterial infection - commonest in the second and third trimesters of pregnancy. Increased severity from influenza H1N1 (2009) infection in pregnancy is associated with pre-existing asthma, maternal smoking and obesity. Pregnant women admitted to hospital with H1N1 (2009) infection are (three times) more likely to deliver pre-term and their babies are (five times) more likely to be stillborn or die in the first week of life. However, pregnant women should also avoid the risk of severe feverish illness at any stage of pregnancy. It is important to remember that flu can cause other types of illness at any stage, including diarrhoea and/or vomiting, muscle and joint inflammation and, rarely, meningitis.
Prevention and treatment of flu in pregnancy:
As in every year, the seasonal influenza vaccine for 2010-2011 contains three different flu virus strains. One of these generates immunity to the H1N1 (2009) flu virus. Vaccination for all at-risk people, including pregnant women, is available through GP surgeries.
All healthcare professionals working in maternity services should be actively encouraged to accept vaccination against seasonal flu, offered through their employer’s Occupational Health Service. This will protect both staff from infection and the pregnant women from exposure to infected staff.
Pregnant women in the high-risk groups for severe and complicated flu should be actively encouraged to have this vaccine. All pregnant women who have not previously received the pandemic flu vaccine (during the pandemic of 2009-2010) should also be encouraged to have one dose of the seasonal flu vaccine, to protect them from infection with the influenza H1N1 (2009) virus. The exception to this is those pregnant women who are immunocompromised. In this situation, if they have not previously received monovalent H1N1 vaccine then one dose of monovalent vaccine should be offered followed by one dose of seasonal vaccine four weeks later.
It is safe to give seasonal flu vaccine at any stage of pregnancy (in some other Western countries, seasonal vaccines have been given to all pregnant women for several years). It is also important to be aware that vaccination of pregnant women has been shown to provide protection for the first 4-6 months of life of the infant, through transfer of maternal antibodies. This is particularly important since only infants over six months are offered the vaccine.
2. Antiviral treatment for flu
While vaccination is considered the first line of defence against flu, antiviral medicines are effective in treating flu, and experience has shown them to be safe at all stages of pregnancy. Some authorities have recommended inhaled zanamivir for pregnant women because of reduced systemic exposure. However, this is not supported by evidence and oseltamivir is not contra-indicated in pregnancy. The European Medicines Agency has recommended that either oral oseltamivir (Tamiflu) capsules or inhaled zanamivir (Relenza) can be taken by pregnant women.
GPs’ contracts allow them to prescribe antiviral medicines according to the guidance provided by the National Institute for Health and Clinical Excellence (NICE). This includes people in high-risk groups for severe and complicated influenza. The Department of Health on 10 December 2010 issued a letter to NHS staff recommending the use of antivirals for the treatment or prevention of flu at the current time.
The regulations governing the use of antivirals by the NHS were changed so that from 1 November 2010 pregnant women are included in the groups of 'at clinical risk' people for whom General Practitioners may prescribe the influenza treatments Tamiflu and Relenza.
Hospital doctors can prescribe antiviral medicines for any patient with symptoms suggestive of flu and should start treatment with Osetamivir immediately, without waiting for laboratory test results.
If a pregnant woman has an influenza-like illness at the current time it is likely to be due to influenza virus infection. All healthcare professionals should be alert to the possibility that the women may have flu and there should be a low threshold for prescribing an antiviral medicine before the results of tests are available.
This advice will be updated if there are any changes in arrangements for vaccination or treatment.
This statement has been agreed by:
Department of Health
Health Protection Agency
Royal College of General Practitioners
Royal College of Midwives
Royal College of Obstetricians & Gynaecologists
Centre for Maternal and Child Enquiries
DOWNLOAD : Government Advice PDF
VIEW : Health Protection Agency (HPA) Advice
24th December 2010
Swine Flu Information
ANNEX A: Q&A
Should pregnant women get the flu jab?
Pregnant women have not routinely been offered seasonal influenza vaccine in the past unless they were in a clinical risk group. However, there is good evidence that all pregnant women are at increased risk from complications if they contract the H1N1 (swine flu) virus. In light of this, pregnant women in clinical risk groups will continue to be offered the seasonal influenza vaccine as usual. But in addition, those pregnant women who are not in a clinical risk group and who have not already received a dose of H1N1 swine influenza vaccine will be offered the trivalent seasonal influenza vaccine this season. GPs should also consider on an individual basis the clinical needs of all their patients.
Is this year’s seasonal influenza vaccine safe for pregnant women?
This year's seasonal flu vaccines are expected to have a similar safety profile to previous seasonal vaccines. These are safe in pregnancy and there is no reason to suspect that incorporation of the 'swine flu' antigen into the vaccine carries any specific risks. Monovalent (single strain) swine flu vaccines were administered to at least half a million pregnant women across Europe during the pandemic with no evidence of any specific safety risks.
Can the flu jab actually cause flu?
No. The vaccine doesn't contain any live virus, so it cannot cause flu. Some people get ‘flu-like symptoms’ - a slight temperature and aching muscles for a couple of days afterwards. Their arm may feel a bit sore where they were injected. Any other reactions are rare - flu jabs have a very good safety profile.
Do I need the flu vaccine if I had the H1N1 vaccine previously?
Each year WHO makes recommendations about the strains to be included in influenza vaccines for the forthcoming winter. The seasonal flu vaccine contains the H1N1 flu strain antigen and the antigens of two other flu viruses that are predicted to be circulating this year. This is so that the vaccine provides protection against the three influenza strains that are predicted to be circulating this year, not just H1N1. JCVI has recommended that patients should have trivalent seasonal vaccine even if they had H1N1 vaccine last year. If they do not accept this advice, they will not be protected from the other two strains that are predicted to be prevalent this year. Furthermore, the duration of the protection provided by flu vaccines is uncertain; patients should therefore take the opportunity to boost their protection against H1N1 for the coming year.
Can I have a seasonal flu vaccine that does not contain H1N1?
This year’s seasonal flu vaccine contains three flu strains: the H1N1 flu strain antigen and the antigens of two other flu viruses that are predicted to be circulating this year. Each year WHO makes recommendations about the strains to be included in influenza vaccines for the coming winter. The influenza A (H1N1)v strain (swine flu) is expected to be the predominant influenza strain once again during the 2010/11 influenza season. For this reason, WHO recommended that this strain be included in the trivalent seasonal influenza vaccine for the 2010/11 influenza season.
Manufacturers follow the WHO advice on strains to include in seasonal vaccines and produce hundreds of millions of doses for the Northern Hemisphere by July of each year. All countries accept the vaccine that has been formulated in accordance with the WHO recommendations. There simply is no production of 'pick and choose' vaccines and it is unhelpful to the public to imply that there could be a choice of vaccine without a particular strain in it.
Has the vaccine from last year been used to make the vaccine for this year?
No. The seasonal influenza vaccines for use this autumn have not been made by incorporating unused stocks of the H1N1 influenza vaccine. They contain the H1N1 flu strain antigen and the antigens of two other flu viruses that are predicted to be circulating this year.
How effective is the flu vaccine?
Studies show that flu vaccines give about 70 to 80 per cent protection against flu infection. That is why it has been recommended to those aged 65 and over and those in an at risk groups. In older people, protection against infection may be lower, but there is good evidence showing that immunisation reduces complications, including bronchopneumonia, hospital admissions and deaths.
Should health staff who had the H1N1 last year October 2009 have the combined vaccine currently being offered in Winter 2010?
The fact that some staff may have had the H1N1 swine flu vaccine last year does not affect advice that they should receive this year’s trivalent seasonal flu vaccine. There are no contraindications to receiving the trivalent seasonal flu vaccine (which contains an H1N1 flu strain) this season if a patient has previously received the H1N1 vaccine.
How safe is the trivalent (seasonal) vaccine?
Patients should be aware that there is no reason to suspect that the inclusion of the H1N1 swine influenza strain in this year's seasonal influenza vaccine will affect the established safety profile of these vaccines. They contain the H1N1 flu strain antigen and the antigens of two other flu viruses that are predicted to be circulating this year. This is in order that the vaccines provide protection against the three influenza strains that are predicted to be circulating this year.
The safety of swine flu vaccines has been thoroughly reviewed by the Medicines and Healthcare products Regulatory Agency (MHRA) and the UK Government’s independent expert advisory committee, the Commission on Human Medicines (CHM). More than six million doses have been given in the UK, with more than 30 million given across Europe. The CHM reviewed the UK safety experience with swine flu vaccines in July and advised that despite substantial usage over a very short time period, and based on both UK and EU/worldwide data, no significant safety issues have been identified and the safety profile is reassuring. There is no evidence to indicate that any H1N1 flu vaccine has caused the death of any patients.
Tens of millions of more doses of various different H1N1 flu vaccines have been given throughout the world over the past year. No serious new risks have been identified and the safety profile is broadly similar to that of seasonal influenza vaccines. The H1N1 flu component has been included in all seasonal flu vaccines this year in all countries, including the vaccines recently used in the southern hemisphere.