Vaccines alternative activity

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					                            4.0 Prevention of Infection
                                      Vaccines

                              Learning Outcomes
                           All students:
National Curriculum Link    Will discover that vaccines help prevent a range of bacterial and
Key Stage 3                    viral infections
Sc1:1a - 1c. 2a – 2p        Will understand that there are not vaccines for all infections
Sc2: 2n, 5c, 5d
                           More able students
Unit of Study
                            Will learn that previously common infections are now rare due to
Unit 8: Microbes and
                              vaccines
         Disease
Unit 9B: Fit and Healthy    Will know that most common infections are not prevented by
            th
Unit 20: 20 Century           vaccines
         Medicine

Estimated Teaching Time
50 minutes                    Background Information
                           Our immune system generally fights any pathogenic microbes that
                           may enter our bodies. Getting plenty of rest, eating the correct foods
                           and getting lots of sleep all helps our immune system to work properly
Key Words                  hence preventing infection.
Antibodies
Antigen                    Another means of assisting our immune system is through
Epidemic                   vaccinations. Vaccines are used to prevent NOT treat infection. A
Herd immunity              vaccine is usually made from weak or inactive versions of the same
Immune                     microbes that make us ill. In some cases, the vaccines are made from
Immunisation               cells which are similar to, but not exact copies of, the microbe cells
Vaccine                    that make us ill.
White blood cells
                           When the vaccine is injected into the body the immune system attacks
                           it as if harmful microbes were attacking the body. The white blood
                           cells create lots of antibodies to attach to the antigens on the
Materials Required         surface of the vaccine cells. Because the vaccine is an extremely
                           weakened version of the microbe the WBC successfully eliminate all
Per student                the vaccine cells and the vaccine will not make you ill. By successfully
□ Copy of SH 1             eliminating all the cells in the vaccine, the immune system remembers
□ Copy of SW 1, SW 2,      how to combat those microbes. The next time microbes carrying the
    SW 3                   same antigen enter the body the immune system is ready to fight it
                           before it has a chance to make you ill.

                           In some cases, the immune system needs reminding and this is why
                           some vaccinations require booster jabs. Some microbes like the
Web Links                  influenza virus, are tricky and change their antigens. This means that
www.who.org                the immune system is no longer equipped to fight them. For this
                           reason, we have annual flu vaccinations.

                           The use of vaccines has meant that a lot of previously common
                           diseases eg. smallpox have now been eradicated. The re-emergence
                           of other diseases in a population, e.g. measles, may be due to not
                           vaccinating a large enough proportion of the population. Epidemics
                           can be prevented by vaccinating part of the population leading to herd
                           immunity.



                             Advance Preparation (10 min)
                           Copy SH 1, SW 1, SW 2 and SW 3 for each student.
                              4.0 Prevention of Infection
                                     Vaccines


     Introduction (15 min)

1. Begin the lesson by asking students which vaccines/immunisations they have had e.g. polio, MMR, TB
   or any holiday vaccinations and if they know what the vaccines were for.
2. Highlight that immune means resistant to disease and that ‘immunisation’ is a way of raising the body’s
   immunity to both bacterial and viral disease.
3. Explain that vaccines/immunisations are a harmless small amount of the microbe/disease outer coat
   which teaches our body how to fight the bad microbe when or if we get attacked by the disease.
4. Explain how vaccines work (outlined in TS 1) with the help of SH 1. Explain that antibodies pass from
   mother to child through breast milk and this helps protect newborn babies from disease.
5. Remind students that microbes can change their outer coats very quickly and that some microbes do
   this so quickly that scientists cannot create vaccines for every infection or have to make a new vaccine
   every year, like the flu vaccine.
6.


     Main Activity (35 min)
1. This activity is best completed in groups of 2 – 3 students.
2. Provide each student with a copy of SH 1 and SW 1, SW 2 and SW 3.
3. Ask the class what they know about the measles? Explain that measles is a highly contagious vaccine-
   preventable disease caused by the measles virus. Measles is one of the most easily spread diseases
   but also the most deadly of all childhood rash/fever illnesses.
4. The World Health Organisation (WHO) examines, records and reports on all health related incidents
   across the globe and produces guidelines and recommendations to help prevent infectious disease
   epidemics. The incidence of deaths across the world due to measles was so high that in the 1980s
   WHO member countries set up national immunisation services in an attempt to eradicate the disease.
5. Tell the class that the table in SW 1 is taken from data collated by WHO, students must manipulate the
   data using the equation provided to an incidence per 1000 population. By doing this, students can then
   compare the incidence of disease between the European and African regions being examined.
6. Provide the class with SW 2, here the groups should create a bar chart using their data illustrating the
   incidence of documented measles cases in both the WHO Europe region and WHO Africa region.
   Discuss with the class the trend of measles cases over the years within each region but also between
   the two regions. Ask students to highlight the most obvious points / trends.
7. Provide each group with a copy of SW 3, and ask them to answer the questions as a group. When
   complete, discuss the answers with the class.
          a. In the 1980s, The World Health organisation (WHO) reported an increasing number of
             countries establishing national immunisation services with increasing immunisation coverage
             in these countries. When do you think these immunisation programmes peaked in the Europe
             and Africa regions.
             The sharp decline in the incidence of measles cases between 1990 and 2000 suggest that the
             immunisation programmes peaked in Europe during the 1990s. In Africa we see 2 cases of
             decline, the implementation of programmes in the 1990s caused the initial decline however in
             2003 and 2006 the measles vaccine coverage was improved causing the second and third
             decline.

          b. Can you think on a reason why there are more outbreaks of measles in Africa than in Europe?
             The immunisation programme was better implemented and followed in the European region
             than in the Africa region with more people becoming vaccinated.
                             4.0 Prevention of Infection
                                      Vaccines


    Main Activity (35 min)

   c.   What issues stop the measles vaccine getting to all the people in Africa?
        War, poverty, suspicion, lack of health education, lack of government good will and lack of
        infrastructure, difficulty delivering the vaccines, and misinformation regarding vaccines all prevent
        the vaccines getting to the people who need it.

   d. What happens when the measles vaccination drops to a low level within a population?
       When the vaccination drops to a low level, people start contracting the disease again leading to a
       re-emergence of the disease.

   e. Why is vaccination not only a personal health issue but also a public health issue?
       Many infectious diseases are extremely contagious, we can vaccinate ourselves against the
       disease but other people can contract the disease and spread it further to unvaccinated people. If
       more people are vaccinated the disease is prevented from circulating. This is why herd immunity
       prevents epidemics. In today’s society where global travel is relatively cheap and easy an infected
       person can carry a disease across the world within 24 hours. Herd immunity prevents the
       epidemics.

   f.   What needs to be done to completely eliminate an infectious disease?
         A vaccination programme which reaches all target groups on a wide-spread continual basis is the
         only means to completely eliminate a disease. However, it is not possible to eliminate all disease
         in this manner as some infectious diseases e.g. avian flu, have other reservoirs outside humans.

   g. Why hasn’t the flu vaccine eliminated the influenza virus?
       A vaccine works by tricking the body into making antibodies to combat a particular infectious
       disease, these antibodies then attach themselves to the antigens in the outer coat of the virus. The
       influenza virus however mutates and changes its outer coat faster than scientists can create
       appropriate vaccines.

   h. Why is a vaccine regarded as a preventative measure and not a treatment?
       Vaccines are used to boost the body’s immunity so that when an infectious disease does enter the
       body, the immune system is ready to fight it preventing the establishment of disease.




   Extension Activity
1. Provide the class with a copy of SW 3.
2. Each student should look examine the world map provided and highlight on the map which vaccines
   are required to visit which countries. Students should also name the disease the vaccine protects
   against and the microbe that causes this disease. Information can be found at www.who.org,
   www.traveldoctor.co.uk or by visiting their local medical centre.
The data below details the population and reported cases of measles in the regions Europe and Africa, as recognised by the World Health Organisation. This
information is usually documented as reported cases per 1000 population for comparison purposes. In the third column, calculate the number of reported
cases per 1000 population using the following equation:  B / (A / 1000) where A = population in thousands and B = reported measles cases.

                                                                                                   WHO Europe Region
                                                                                   Population in       Reported          Reported cases/1000
                                                                                    thousands          measles               population
                                                                           Year                         cases
                                                                           1990       522 443          234 827
                                                                           2000       895 997           37 421
                                                                           2002       901 440           46 714
                                                                           2003       904 883           28 199
                                                                           2004       908 411           29 503
                                                                           2005       911 776           37 332
                                                                           2006       915 553           52 765

                                                                                                   WHO Africa Region
                                                                                   Population in       Reported          Reported cases/1000
                                                                                    thousands          measles               population
                                                                           Year                         cases
                                                                           1990       510 853          481 204
                                                                           2000       670 918          520 102
                                                                           2002       705 094          286 380
                                                                           2003       722 580          403 572
                                                                           2004       740 358          220 732
                                                                           2005       758 439          316 224
                                                                           2006       776 830           99 339
                     Using the data in SW 1 complete the following table and graph:
                                   Number of reported cases of measles per 1000
                         Year           Europe                      Africa
                         1990
                         2000
                         2002
                         2003
                         2004
                         2005
             Title       2006
 100



        90
                                                                                In order for other
                                                                              people to be able to
                                                                             read your results, it is
        80                                                                     important that the
                                                                                 graph has a title
                                                                              explaining what you
                                                                               are trying to show
        70
                                                                              and that the X and Y
                                                                                axis are labelled
                                                                                  appropriately.
        60



        50



        40



        30


                                                                                     Legend
LABEL




        20



        10



         0     1990      2000    2002   2003     2004    2005     2006
                     LABEL
Conclusions
1. In the 1980’s the World Health Organisation (WHO) reported an increasing number of
   countries establishing national immunisation services with increasing immunisation coverage
   in these countries. When do you think these immunisation programmes peaked in the
   Europe and Africa regions. Provide a reason for your answer.
   _________________________________________________________________________
   _________________________________________________________________________
   _________________________________________________________________________
   _________________________________________________________________________

2. Can you think on a reason why there are more outbreaks of measles in Africa than in
   Europe?
   _________________________________________________________________________
   _________________________________________________________________________

3. What issues stop the measles vaccine getting to all the people in Africa?
   _________________________________________________________________________
   _________________________________________________________________________
   _________________________________________________________________________

4. What happens when the measles vaccination drops to a low level within the population?
   _________________________________________________________________________
   _________________________________________________________________________
   _________________________________________________________________________

5. Why is vaccination not only a personal health issue but also a public health issue?
   _________________________________________________________________________
   _________________________________________________________________________
   _________________________________________________________________________

6. What needs to be done to completely eliminate an infectious disease?
   _________________________________________________________________________
   _________________________________________________________________________

7. Why hasn’t the flu vaccine eliminated the influenza virus?
   _________________________________________________________________________
   _________________________________________________________________________
   _________________________________________________________________________
8. Why is a vaccine regarded as a preventative measure and not a treatment?
   _________________________________________________________________________
   _________________________________________________________________________
   _________________________________________________________________________
 In the boxes provided, compile a list of vaccines required, if any, to visit each of the regions on the map.

                                                              Western Europe:
                        Canada:
                                                                                                       Russia:




                                                                                                                Far East:




                                                                                  Asia:


S. America:
                                                                      Africa:



                                                                                          Australia:
                                                Fact Sheet

       The immune
   system is our main
   defence against any
  pathogenic microbes.
    Exercise, rest and
 a balanced diet all help
   our immune system
    work properly and                                         Vaccinations can also help
         prevent                                               our immune system. They
        infection.                                                     are used
                                                             to prevent NOT treat infection
                                                              by stimulating the immune
                                                               system to recognise and
                                                             destroy the disease causing
                                                                microbe. Vaccines are a
                                                                weak or inactive version
                                                              of the pathogenic microbe.




                          The immune system
                     attacks the vaccine thinking
                 it is a harmful microbe. The white
               blood cells create lots of antibodies
                which attach to the antigens on the
                  surface of the vaccine cells. The
              antibodies destroy all the vaccine cells
                    before it can make you ill. The
                 antibodies then stay in the blood
                 stream for many years, waiting to
                      attack and destroy the real
                     pathogenic microbes if they
                          ever enter the body.




                                                                          Some microbes like
                                                                        the flu, are tricky and
                                                                      change their antigens.
                                                                          This means that the
                                                                        immune system can’t
                                                                      remember how to fight
                                                                       them. For this reason,
                                                                           We have annual flu
                                                                                 vaccinations.




The use of vaccines has meant
that a lot of previously common
diseases eg. Smallpox have now been
eliminated. While a vaccine protects an
individual an infectious disease will only be
eradicated if vaccines are used on a
wide-spread population wide basis. This is
known as herd immunity. Epidemics can be
prevented by herd immunity.

				
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posted:9/11/2012
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