LinkedIn emplea cookies para mejorar la funcionalidad y el rendimiento de nuestro sitio web, así como para ofrecer publicidad relevante. Si continúas navegando por ese sitio web, aceptas el uso de cookies. Consulta nuestras Condiciones de uso y nuestra Política de privacidad para más información.
LinkedIn emplea cookies para mejorar la funcionalidad y el rendimiento de nuestro sitio web, así como para ofrecer publicidad relevante. Si continúas navegando por ese sitio web, aceptas el uso de cookies. Consulta nuestra Política de privacidad y nuestras Condiciones de uso para más información.
Why am I going to talk about Vaccination and immunisation?. Well it is recognised as a public health intervention of great importance as is shown by this statement from the WHO. Globally the WHO estimates that the use of vaccines prevents in the region of 2 million deaths every year. In addition many of the devastating illnesses which used to scurge many of the industrialised nations have now been contained because of the development and widespread distribution of safe, effective and affordable vaccines.
Vaccination is not a new idea. As early as the 6 th century there are reports from China of smallpox innoculations (known as variolation) where powdered scabs from infected people were transferred to healthy individuals by inhaling through the nose. In 1718 Lady Mary Wortley Montague (wife of the British ambassador to Turkey) reported that the Turks had a habit of deliberately innoculating themselves with fluid taken from mild cases of smallpox and that she had innoculated her own children. In 1796 it was Edward Jenner who performed the world’s first vaccination in the UK. Taking pus from a cowpox lesion on a milkmaid’s hand. Jenner inoculated an eight year old boy James Phipps. 6 weeks later Jenner variolated two sites on Phipps’s arm with smallpox yet the boy was unaffected by this as well as subsequent exposures. This was the foundation for modern vaccinology. Incidently,The word vaccination was first used by Edward Jenner and comes from the latin word vacca meaning cow. Until 1885 vaccines referred only to cowpox innoculation for smallpox, then Louis Pasteur developed what he called rabies vaccine.
Just a quick word on terminology. The words vaccination and immunisation tend to be used almost interchangeably nowadays (and I will probably do so thoughout this presentation!) however, the latter term (immunisation) is a more inclusive term because it implies that the administration of an immunologic agent actually results in the development of adequate immunity.
Active immunity – this is an antibody response produced by an individuals own immune system and is usually long lasting. It can be acquired by exposure to natural disease or by vaccination. Vaccines generally produce immunity similar to that provided by the natural infection, but without the risk from the disease and its complications. Passive immunity – this is protection which is provided by the transfer of antibodies from immune individuals, most commonly from a mother to an infant via the placenta, or less often from the transfusion of blood or blood products containing immunoglobulins. Mothers milk is also rich in antibodies and thus breastfeeding increases a babies’ defence against infection. This type of immunity is called passive immunity as the recipients own immune system is not involved. The protection provided by passive immunity is temporary, lasting commonly , only for a few weeks or months.
Smallpox was eradicated worldwide in 1980 – the last fatal case was in 1978 – and it was an infection in a laboratory worker in Birmingham. The global eradication of polio is a target for WHO – they aim to have the cessation of all wild polio transmission worldwide by the end of 2012. (Work is being financed by Bill Gates of microsoft fame in conjunction with the UK and Germany). Europe has been polio free since 2002.
Diseases such as pertussis , measles and typhoid can be silently transmitted by asymptomatic people and this allows infections to spread from a reservoir of carriers. There is some discussion that H1N1 may have been transferred asymptomatically within the population by people who had either no or minor symptoms of infection. The influenza virus can have an antigenic drift which means the prevalent virus can change from year to year, hence why a new vaccine with a different antigenic component is required on an annual basis. A major change in the antigenic component of the virus – known as an antigenic shift – can result in pandemic as the makeup of the virus has changed so significantly that few of the population have been exposed to the virus previously and are then less likely to have developed immunity. Tetanus has spores which are found in the soil and as it is impossible to eliminate all the spores – the risk of tetanus is always going to be around.
One of the important concepts of vaccination is that of herd or population immunity.
Will only work for diseases that are transmitted between people and not for diseases that can be caught from animals or other reservoirs. So basically being vaccinated is not soley for the benefit of the individual being vaccinated – but it is also for the greater good – to help others.
DoH sets national policies outlining which vaccines will be used in what populations . Policies cover UK wide childhood and other vaccination programmes such as seasonal influenza vaccination.
The next two slides give an indication of the different diseases which the current vaccination programmes in the UK protect against. Yellow diamond – national childhood immunisation programme Green diamond – other national immunisation programmes e.g targeted programme HPV 12-13yr old girls seasonal influenza programme
This is the current UK childhood vaccination schedule (May 2011) The childhood vaccination programme schedules 12 separate injections in various combinations against 10 infectious diseases before the age of 5. Which costs in the region of £200 per child. D = diphtheria(high dose), T =tetanus, aP = acellular pertussis, IPV = inactivated polio vaccine, Hib = Haemophilus influenzae type b MMR= measles, mumps, and rubella, PCV = pneumococcal conjugate vaccine. Men C = meningitis C, d = diphtheria (low dose) HPV (human papilloma virus)- 3 injections over 6 months.
SIRS is part of Child Health surveillance and most GP practices in scotland have signed up to the system. Generates list which are sent to practices which informs them which children are due to be vaccines – individual invitations for children can also be sent out. Once the vaccines are administered the information is then fed back to SIRS to be recorded.
So how effective are the immunisation programmes? A good example is diphtheria Prior to the 1940’s this was a common disease in the UK with 61,000 reported cases and 3,283 deaths in 1940, however with the introduction of a national vaccination programme there was a dramatic fall in the number of notified cases and deaths from the disease. By 1957 there were only 38 reported cases and 6 deaths. Diphtheria is still reported around the world and any cases seen recently in the UK have been in people who have travelled to areas such as SE Asia, Africa etc where the disease is still prevalent. The figures on the slide, show how more recent vaccines have also managed to reduce the incidence of disease.
So what are the challenges of delivering a vaccination programme. Will talk about each of these individually.
Scepticism and suspicion about immunisation has always been an issue. No shortage of cartoons in the early 1800’s mocking Jenner and depicting the transformation of the recently vaccinated into sickly cows and fantastical beasts. There may, however be several reasons which may be a barrier to immunisation. Take a few minutes to think about your own situation? Were you offered the seasonal flu vaccine recently or the H1N1 vaccine last year? Did you have it – if not, what were the barriers which prevented you from doing so?. You may have young children or have friends who have young children – what barriers may stop the offer of vaccination for them being accepted?.
These are just some examples of barriers which may be in place and you may recognise some of them from your own personal experience. Again we will look at these individually.
Despite being a ‘killed’ vaccine some people still think that the flu vaccine can give you the flu – this is untrue. As the vaccine takes approx. 10 days to become effective, you could possible catch the flu before the vaccine takes effect. Also you may have a flu like illness or just ‘man flu’! The benefits of multi-component vaccines mean fewer injections for children, fewer visits therefore it is easier to ensure no vaccines are missed and children are protected against the maximum number of infectious diseases in the minimum amount of time. Some people, however, do have concerns that children may not be able to respond to a large number of antigens at the same time. Children, however, are exposed to may foreign antigens each day and research has estimated that an infant could respond to at least 10,000 vaccines (antigens) at once. Single component vaccines are not licensed in the UK and those available will have to have been imported from abroad. Administering these vaccines singly takes longer for the child to obtain immunity and thus may be left exposed to infection. More visits and injections will also be required. The risk of serious side effects from vaccines is very rare, although media reports may make it seem otherwise. In addition many younger people have not had personal experience of the serious complication that can result from many of the infections that are now prevented by vaccination and thus do not appreciated the risks which a child may be exposed to if they catch the disease. The ‘Green Book’ which is listed in the references at the end does into great detail about the individual diseases and their complications and I would recommend reading about these diseases to give yourselves a greater appreciation of the problems. Complications from measles for example can affect 1 in every 15 children. These complications include chest infections, fits , encephalitis and brain damage. In very serious cases measles can kill. 1 in about every 5000 children ill with measles is likely to die and recent epidemics in industrialised countries have had higher rates. In the UK there were no deaths between 1992-2006. But was one death in 2006 and one death this year.
This slide shows the reality of infection with polio and something which was a common sight before the introduction of vaccination programmes. This is a ward full of Iron lungs in Los Angeles County Hospital during polio epidemic in 1950’s. It was alos common place to see children and adults who had been paralysed by polio in braces or with some degree of disability or impairment as a result of being infected by polio.
Issue around the MMR vaccine still lingers on – this headline was regarding thiomersal being present in the vaccine. However major damage to the uptake of MMR vaccine was caused by a report in the Lancet by Dr. Andrew Wakefield and his team who initially suggested that there was a link between the vaccine and autism. This produced a media frenzy and TV interviews with parents who said that there children had been damaged etc. However, the Wakefield study was subsequently retracted and any causal links between the vaccine and autism has been discredited, but despite this the MMR uptake figures have not yet entirely recovered, and in some areas, including parts of London, due to the low herd immunity, there is genuine fear of an epidemic. A series of articles by journalist Brian Deer which discusses some of the bogus claims made was published in the BMJ in January 2011 and may be an interesting read to those wanting to find out more of the background to this story.
Some of the headlines after the Wakefield paper was retracted. However, MMR vaccination rates in some parts of the country are still not at levels required for herd immunity. A legacy of this bogus work which may have long lasting consequences for some individuals who may not have been vaccinated due to parental concerns.
For example, a recent shortage of pre-school booster vaccines resulted in alternative vaccines having to be used and an extra injection being given. In such instances increasing demands can be put on GP practices who have to make additional arrangements to undertake the extra injections required. So why can we have problems with vaccine supply?
Vaccine production is an extremely long and complicated process. Vaccines are biopharmaceutical products and hence there may be difficulties in producing antigens, mixing antigens without interactions and then putting them into an acceptable pharmaceutical product. Aduvants e.g aluminium may be required to be added. These reduce the amount of purified antigen which is required and can help boost the immune response. (Was used in the H1N1 Pandemrix vaccine as only a small amount of antigen was available and this meant a smaller amount could be used in each dose and the adjuvant would help produce a better immune reponse). Also to prevent bacteral growth or stabilise the antigen vaccines may contain small amounts of antibiotics or other chemicals.
Examples of some of the costs per dose.
Examples of main types of vaccine incidents seen in a national survey – and reflected in those reported in NHS Lothian. Those administering vaccines need to be aware of where and how these errors can happen and avoid. Can be person or system driven. e.G Out of date flu vaccine administered as left over vaccines from previous years campaign not removed from fridge and destroyed. Also expiry dates not checked before administration of vaccine. Can be confusion with names e.g Revaxis and Repevax – similar names, different vaccines. Likewise the pneumococcal vaccines Pneumovax (Pneumococcal polysaccharide) and Prevenar (pneumococcal conjugate vaccine) are two vaccines used for two different age group (although may be a few exceptions). Be aware as to which vaccine is used in which age group. Try to avoid shortening of the vaccine name to …vax. e,.g fluvax, pneumovax as this can lead to confusion as to which vaccine is required.
Some vaccines such as diphtheria, polio, tetanus etc are sometimes offered free from GP practices as they are part of the national immunisation programme although in some instances you may be required to pay a prescription charge. Other vaccines require a private prescription and the patient will have to pay for both the supply and administration of the vaccine. This can prove to be costly e.g course of 3 rabies vaccines and administration is approx £90. (Costs may vary from surgery to surgery). Thus because of the additional cost to a possibly expensive long haul trip some people may decide not to be vaccinated. So should the NHS pay for all of these vaccines?. You could argue that people taking these type of trips should factor the cost into their trip and that they are possibly should pay for vaccinations if they can afford to pay for the trip. However, if they catch a disease on the trip because they were not vaccinated, do the costs that the NHS will incur from treating the patient when they return home outweigh the cost of the initial vaccine? MMR cases being seen in Europe particularly France so WHO is currently advocating MMR vaccination before travel (I dose for adults/adolescents if unsure about immunity status).
Vaccination and immunisation jane renton - principal pharmacist - nhs lothian
Vaccination and Immunisation Jane Renton Principal Pharmacist NHS Lothian
<ul><li>“ The two public health interventions that have had the greatest impact on the worlds health are clean water and vaccines” WHO </li></ul>
History of Vaccination <ul><li>1796 -Jenner – cowpox </li></ul><ul><li>1885 - Pasteur – cholera, diphtheria, chickenpox, rabies </li></ul><ul><li>1911 - first typhoid vaccine </li></ul><ul><li>1927 - first tetanus vaccine </li></ul><ul><li>1931 - Calmette & Guerin – first crude BCG </li></ul><ul><li>1936 - influenza </li></ul><ul><li>Modern era of vaccination </li></ul><ul><li>1940 - diphtheria national programme in UK </li></ul><ul><li>1950’s - polio, pertussis, modern BCG </li></ul><ul><li>1960’s - measles, mumps & rubella, modern tetanus </li></ul><ul><li>1980’s - H. Influenzae B (Hib) </li></ul><ul><li>2000’s - Meningitis C, Human papilloma virus (HPV) </li></ul>
Terminology! <ul><li>Vaccination: the process of administering a vaccine </li></ul><ul><li>Immunisation: the process of inducing immunity to disease </li></ul><ul><li>Immunity is usually acquired naturally, but can be induced by vaccination </li></ul>
Immunity <ul><li>Active </li></ul><ul><li>An antibody response formed by the body </li></ul><ul><li>Induced by vaccine or natural infection </li></ul><ul><li>Passive </li></ul><ul><li>Antibody is donated </li></ul><ul><li>e.g. immunoglobulin or maternal antibody passed to infant </li></ul>
Why immunise? <ul><li>To prevent or protect against serious disease </li></ul><ul><li>To eliminate a particular disease from a defined population </li></ul><ul><li>To eradicate a disease entirely e.g. smallpox </li></ul>
<ul><li>However it is not possible to eradicate all vaccine-preventable diseases: </li></ul><ul><ul><li>Asymptomatic carriage </li></ul></ul><ul><ul><li>Mutating organisms e.g. influenza </li></ul></ul><ul><ul><li>Animal reservoirs e.g. SARS, avian influenza </li></ul></ul><ul><ul><li>Environmental reservoirs e.g. tetanus </li></ul></ul><ul><ul><li>Global travel/mass immigration </li></ul></ul>
Population (herd) immunity <ul><li>“ Population immunity is the state achieved when immunisation programmes reach sufficiently high coverage of the target population to interrupt transmission within the community” </li></ul><ul><li>Depends on: </li></ul><ul><ul><li>Degree to which disease is infectious </li></ul></ul><ul><ul><li>Efficacy of vaccines </li></ul></ul><ul><ul><li>Vulnerability of population </li></ul></ul><ul><ul><li>Environmental factors </li></ul></ul>
Herd Immunity <ul><li>Protects people unable to be vaccinated i.e too young, have health problems, pregnant. </li></ul><ul><li>Thresholds (% of population that needs to be immune) are quite high. </li></ul><ul><ul><li>Polio 80-86% </li></ul></ul><ul><ul><li>Diphtheria 85% </li></ul></ul><ul><ul><li>Measles 95% </li></ul></ul>
UK Childhood Vaccination schedule <ul><li>When to immunise What is given </li></ul><ul><li>2 months old DTaP/IPV/Hib (Pediacel) & PCV (Prevenar 13) </li></ul><ul><li>3 months old DTaP/IPV/Hib (Pediacel) & Men C </li></ul><ul><li>4 months old DTaP/IPV/Hib (Pediacel) & PCV & MenC </li></ul><ul><li>Between 12 and Hib/ Men C & PCV & MMR </li></ul><ul><li>13 months old </li></ul><ul><li>3 years and 4months or dTaP/IPV or DTaP/IPV & </li></ul><ul><li>As soon after. MMR </li></ul><ul><li>13 to 18 years old Td/IPV (Revaxis) </li></ul><ul><li>Girls aged 12-13yrs HPV (Cervarix) </li></ul>
SIRS <ul><li>Scottish Immunisation Recall System </li></ul><ul><li>File opened at birth </li></ul><ul><li>Should have complete immunisation record up to school leaving </li></ul><ul><li>Records immunisations which are scheduled </li></ul><ul><li>Unscheduled attendee form to be completed for all non-recall vaccinations </li></ul>
Successes <ul><li>Efficacy of National Childhood Immunisation Programme </li></ul><ul><ul><li>Cases of Measles notified in under 15’s in Scotland from over 12,000 in 1976 to 147 in 2007. </li></ul></ul><ul><ul><li>Rubella from 6,000 cases in 1989 to 131 in 2007. </li></ul></ul><ul><ul><li>Pertussis from 4,000 cases in 1982 to 62 in 2007. </li></ul></ul><ul><ul><li>Data: ISD </li></ul></ul>
Challenges <ul><li>Breaking down barriers to immunisation uptake. </li></ul><ul><li>Cold chain issues </li></ul><ul><li>Preventing immunisation errors </li></ul>
Barriers to Immunisation Uptake <ul><li>Poor information/ misconceptions/ myths </li></ul><ul><li>Conflicting advice: family, media etc </li></ul><ul><li>Inconvenience: time, transport, lack of flexibility in system </li></ul><ul><li>Vaccine supply issues </li></ul>
Poor information/ misconceptions/ myths <ul><li>Misconceptions have always been around e.g </li></ul><ul><ul><li>Vaccines can give you the infection e.g ‘flu </li></ul></ul><ul><ul><li>Multicomponent vaccines overload the immune system </li></ul></ul><ul><ul><li>Giving vaccines singly is safer </li></ul></ul><ul><ul><li>Risk from vaccine is worse than the infection – no-one dies these days from measles! </li></ul></ul><ul><ul><li>etc.etc.etc………….. </li></ul></ul>
Conflicting advice: family, media etc <ul><li>Provocative media headlines </li></ul><ul><ul><li>e.g “Autism: new risk in NHS vaccine” ( Scotsman 13 March 2004 ) </li></ul></ul><ul><ul><li>Anecdotal parental reports of autism after MMR vaccination </li></ul></ul><ul><li>Emotional impact – creates confusion/ concern in parents </li></ul><ul><li>Once damage done is difficult to rectify despite evidence </li></ul>
Inconvenience: e.g time, system inflexibility <ul><li>Working parents have difficulty in attending fixed daytime immunisation clinics. </li></ul><ul><li>Yellow fever vaccines only available from designated clinics </li></ul><ul><li>Changes being made – ‘flu clinics on Saturdays, Community pharmacies undertaking ‘flu vaccines. </li></ul>
Vaccine supply issues <ul><li>Can affect uptake of immunisation </li></ul><ul><ul><li>Clinics cancelled – patients forget to return for next dose </li></ul></ul><ul><ul><li>Increased number of injections having to be given puts people off! </li></ul></ul>
Vaccine Production <ul><li>Two main stages </li></ul><ul><ul><li>Biological - antigen preparation </li></ul></ul><ul><ul><li>Pharmaceutical - ready to use product </li></ul></ul><ul><li>Production cycles are long </li></ul><ul><ul><li>Tetanus vaccine - 9-10 months </li></ul></ul><ul><ul><li>Diphtheria vaccine - 11 months </li></ul></ul><ul><li>Rigorous QA checks </li></ul>
Cold Chain <ul><li>System of transporting and storing vaccines within the recommended temperature range of 2 – 8 0 C </li></ul>
Why is the cold chain important? <ul><li>Effectiveness of vaccines cannot be guaranteed if exposed to temperature extremes. </li></ul><ul><li>Ensures compliance with manufacturers’ SPC/MA </li></ul><ul><li>Provides assurance/ confidence in potency of the product </li></ul><ul><li>Ensures patient obtains maximum benefit from immunisation </li></ul>
Risks associated with incorrect vaccine storage <ul><li>Risk to patient </li></ul><ul><ul><li>Risk of acquiring infection due to ineffective vaccination </li></ul></ul><ul><ul><li>Risks associated with possible re-vaccination </li></ul></ul><ul><li>Risk to NHS/ Healthcare professionals </li></ul><ul><ul><li>Loss of confidence in service </li></ul></ul>
Immunisation administration errors <ul><li>e.g. Administration of the wrong vaccine </li></ul><ul><li>Administration of extra/ unnecessary </li></ul><ul><li>vaccines </li></ul><ul><li>Administration of out of date vaccines </li></ul><ul><li>Most are avoidable! </li></ul><ul><li>All should be reported using medication incident reporting systems </li></ul><ul><li>Reports should be reviewed and analysed </li></ul>
Travel Vaccination <ul><li>Increased risk of transmission of infectious disease due to dramatic in global travel </li></ul><ul><li>Study revealed 67% of travellers to high/medium risk areas had not taken medical advice </li></ul><ul><li>Need consultation at least 1 month before travel </li></ul><ul><li>Are two compulsory vaccinations – yellow fever/ meningitis </li></ul>
Travel Vaccines <ul><li>Cost – is an area of much debate!. </li></ul><ul><li>Some vaccines can be prescribed on a GP10 </li></ul><ul><ul><li>Td/IPV, MMR, Hep A, typhoid </li></ul></ul><ul><li>Others require private prescription </li></ul><ul><ul><li>Rabies, Japanese encephalitis, tick borne encephalitis, yellow fever </li></ul></ul>
And finally…. <ul><li>“ Protection from infectious diseases is one of the greatest benefits that any government can ensure for each generation” </li></ul><ul><li>KA Annan </li></ul>
References and Resources <ul><li>‘ The Green Book’, www.dh.gov.uk </li></ul><ul><li>www.immunisation.nhs.uk </li></ul><ul><li>www.hps.scot.nhs.uk </li></ul><ul><li>www.immunisationscotland.org.uk </li></ul><ul><li>www.uvig.org (UK Vaccine Industry Group) </li></ul><ul><li>www.hpa.org.uk </li></ul>