Immunisation

The health and education sablah is going to talk a bout this title in a well detailed manner starting from this thread and followed by other related posts , me and fahad will try to share with u everything we know with u regarding this vital issue , and we will try to go through the successful programme of immunisation implemented in the sultanate by the ministry of health , your contraption is very well appreciated ¡K


Before introducing any vaccine into practice there are few points to be considered in order to achieve the best outcome desired for such clinical practice.

1. Is the disease of public health importance common / serious features.

The disease has to be of great importance to the public , not necessarily common , but of major and sig. Complications.

2. Can a safe and effective vaccine be produced.

Safety

Once justified to produce the vaccine , then a candidate vaccine produced which then goes into a serious of trials to examine it¡¦s safety and efficacy.

The most common adverse effects
- mild form of the disease { live vaccine}
- fever {live vaccine}
- local reaction { with the attenuated vaccine}

the trial prior to release is carried out in 3 phases :-
phase 1 : given to a small number of volunteers ( 50 )
- major side effects recorded.
- blood tests ( for the antibodies produced ) .

phase 2 : large number of people ( hundreds )
- adverse reactions.
- blood testes.
Compare with those who did not receive the vaccine ( by assessing the antibodies level )

Phase 3 : larger group ( 1000s)
Compare to unvaccinated group.

Efficacy

The vaccine is effective if it significantly reduce the disease incidence in the immunised group compared with that in the unvaccinated group.

3.Is the vaccine cost effective?
If saving produced by the vaccine more than balanced the cost of it is delivery , this is an important factor in favour of recommending it¡¦s use.

If it is effective but high cost , then it is controversial .


4.Is it acceptable by the recipients?
Vaccine of many doses by injection may not be accepted by some parents.

5. The target population
Some diseases are confined to a particular group of population , so it may be restricted to those groups only and not given to all , Eg influenza vaccine .

In deciding a bout the target population what is the aim?

1. control ( reduction of mortality , morbidity , incidence).
2. Elimination of the disease.
3. Elimination of the infections. Eg. MMR , Diph.
4. Eradication ( permanent) eg. Poliomyelitis , measles.
5. Extinction ( the infective element is no longer exist ).

6. Can enough people be vaccinated in the total population

The chance of infection in the un-immunised persons diminishes , the greater the proportion of the immunisation.

Excellent thread!!!!

Thank you for your efforts Samy & FaHad..

I'll be waiting for the next parts...

thanx samy, i was waiting for u...
yeah friends we are going to talk about vaccinations and how much oman reached in this issue and how effective is the immunization program in oman... and try to talk about bout each single vaccin and related information about it and many many more in sha'a allah...

remeber everyone here is going to be a father or mother ( in sha'a allah) , and u have to know about immunization and why ur giving ur child such chemicals..

i will post today ins ha'a allah our immunization programm...

so keep in touch and thanx samy for ur co-operation.:D

The expanded programm of immunization in Oman…
First of all it is a free immunization for all children in Oman including foreigners , this is because Oman has a goal to eradicate all serious diseases which can kill the child….. so imagine how much one vaccin cost and how many children is born per yr in oman…

The following is the latest edition of immunization program:
at birth BCG , OPV , HBV-1
at 6 week OPV, HBV-2 , DPT-1
at 3 month OPV-1 , Hib-1 , DPT-2
at 5 month OPV-2 , Hib-2 , DPT-3
at 7 month OPV-3 , Hib-3 , HBV-3 , + vitamin A (100,000 IU= international unit)..
at 12 month measles , vit. A
at 18 monthOPV booster , DPT booster, MMR…

[color=blue] seem this will be confusing for u… but we are going to talk in detail and in simple way about each vaccine, its side effect, plus its effectiveness.. and the statistics of the fall in the incidence of a particular disease in Oman..

Let us talk first about BCG:::

what is BCG
it stand for bacilli Calmette Gurein (BCG).. which is a live attenuated Mycobacterium bovis (M.bovis)..

what is used for ? used as a vaccination for tuberculosis (T.B) ,AL-DAREN, which is caused by Mycobacterium tuberculosis( M. tunrculosis)

why we use M.bovis to immunize against M. tuberculosis?
this is because these two bacteria belong to same family ( Mycobacterium) , thus they share some structural similarities.

what does live attenuated signifies
live attenuated means that the vaccine which is used contain live bacteria but it has be weaken by some methods , thus it goes to the body without causing problem, but the immune system recognize it and produces antibodies against it and also it destroys the weak bacteria in the vaccine…
but because it is a live attenuated , it can not be used for a PERSON with weak immunity which can not face the weak bacteria… these patients include those with AIDS , diabetes, using steroid drugs or chemotherapy, malnourished ..etc…

Oman and BCG
the national TB control program (NTP) was initiated in 1981 and reorganized in 1991, plus the direct observation treatment schedule (DOTS) started in 1996 ( in Muscat is in Rahma hospital)… other plans to eliminate TB is introduction of BCG to the extended program of immunization (EPI)..

How much Oman achieved with the BCG
the coverage of BCG vaccination is nearly 100% , I have a graph which shows percentage of coverage but I will show it later after talking about all vaccines , cos it shows the coverage of whole vaccines.

Regarding the decline in the incidence of TB after introduction of BCG , this graph shows this decline..( look at the attachment)

U can see the number decreased from 405 cases in 1991 to 276 in 1995..

if coverage is 100% , why there is still TB cases??
it is found that BCG does not decrease the overall incidences of TB in the population..

if that is the case , why we use it for our children
when a child is infected with TB , in most of the cases it affects the lungs but then it can be progressive like an evil and spread to the body like milliary TB and brain covers causing meningeal TB..
BCG has significant effect in protecting the child from severe form of TB which can kill the child… and this is why BCG vaccination is mostly done in endemic areas ( area with a lot of TB cases) like Oman
But this effect is not found in adults, thus BCG vaccination of adult is not useful..

I will talk a bout T.B in children
A child is infected from a person who is coughing up the tubercle bacilli. When the child is under five years of age that person is usually within the households or very close to it. Infection can also be transmitted through contaminated unboiled milk.
Infection is in one or both lungs , causing a lesion in the site with enlargement of the neighbouring lymph nodes forming what is called ¡§ primary complex¡¨. But when the infection is acquired from drinking contaminated milk , the primary focus is the intestinal tract with nodes in the mesentery.
Diagnostic criteria :
„h Symptoms and signs
Persistent fever > 4 wks , persistent cough > 4 wks or more . repeated mild acute respiratory infections episodes of more than 10 / year. Failure to thrive or failure to gain weight for 3 successive months. Unwilling to play , irritability , poor appetite.
„h History of contact.
„h Hypersensitivity ( MT) . mantoux test positive > 15 mm in circumference in the area of injected PPD.
„h Radiological examination with evidence.

Treatment wit the ATT is given in a period varies according to the diagnostic criteria and the severity from 8 ¡V 9 months.
In general the more sever the tuberculous complications are treated with a larger number of drugs.

Prognosis:
In patient with an intact immune system, modern ATT offers good potential for recovery.
Yet organisms resistant to multiple drugs are increasingly common.
Resistance emerges either because the physician prescribes an inadequate regimen or because the patients discontinues medications.

thanx samy for the informations..:cool:
Now it is the time to talk about OPV:::

what is OPV it stands for oral polio vaccine. Against polio ( poliomyelitis) which is in Arabic called shalal al-atfaal.. Polio is transmitted by a virus which is an enterovirus from the family picornaviridae and they enter the body from the gut ( thus the word come enterovirus).

brief information about polio
the virus first lives in the gut and throat and can cause sore throat and diarrhea but in some patient it spread to blood and causes vague flulike illness and also it can spread to lymph nodes..
but in few patients it spread to central nervous system and causes paralysis, but in some destruction is not complete and power returns but in other destruction is complete so paralysis will be permanent..
Thus in Oman any child presents with acute flaccid paralysis , his/her stool should be checked for polio virus. But don’t worry acute paralysis can be caused by other virus and bacteria which can be treated properly.

is there is only one type of polio virus
poliovirus has 3 types ( serotypes) ( Brunhile, Lansing, Leon).. and body produces three different antibodies against them .. thus the vaccine should contain the 3 o them.
what is OPV exactly??
it is alive attenuated polio virus, again it has a risk o cause the disease to the child if hi health condition is not well.. thus they discovered another vaccine called IPV ( inactivated polio vaccine ( which is a dead virus).

some features of OPV
it is givin orally( by mouth) as drops , does not required a trained person to give it, and it is inexpensive.. thus it is better to be ued for national immunization programs.

immunity from OPV
immunity from polio virus is life long lasting , and because the virus is alive thus it can be shed in the stool of the immunized child and this will cause immunization in the people who are close contact with the child..

what about IPV this is as I said is an inactive virus thus does not have problem in affecting the body. Its effect is similar to OPV plus it has no affect in immuning people close contact with the child because seem that this dead vaccine is not shed in stool but remain in thorax activating immune system.

How much Oman achieved with OPV
see the attached file.. and u will find that Oman has achieved its goal in eradicating polio 100%.. u can see that in 1981 there were 43 cases but in 1990 and onward no any cases were detected.. Thus keep u child vaccinated.

Excellent efforts man :)
i would like to add few comments to what u said and i will concentrate on it inrespect of child health

polivirus infection is subclinical in 90-95% of cases; it it causes non-specific febrile illness in a bout 5% of cases and aseptic meningitis or paralytic disease in 1-3%.
in endemic areas , most older children and adults are immune cuz of prior inappearent infections.

complications and sequelae:

complications are the results of the acute and perminant effects of paralysis.Respiratory, Pharyngeal,bladder and bowel malfunction are most critical.Deaths are usually due to complications arising from respiratory dysfunction.Limbs injured near the time of infection , such as by intramuscular injections, excessive prior use , or trauma , tend to be most severely involved and have the worst prognosis for recovery ( provocation paralysis). postpolio muscular atrophy occurs in 30-40% of paralysed limbs 20-30 years later; characterised by increasing weakness and fasciculations in previously affected, partially recovered limbs.
prognosis:

postpolio paralysis is mild in a bout 30% , permanent in 15% and result in death in 5-10%.Disease is worse in adults and pregnant women than in children.

thanx bro. now i ma preparing for another vaccine...
i feel it is nice to know about vaccine that we are giving o our children..

Now it is the turn for the HBV…
What is HBV
It is a vaccine for hepatitis B ..

Some brief information about hepatitis B
It is well known disease which affect the liver and causes jaundice , it is transmitted in similar way like HIV from infected blodod, body fluid, from mother to the baby
( vertical transmission)

What is HBV exactly?
It is a subunit ( part of ) of the hepatitis B viryus called the surface antigen .. thus when u inject this antigen ( protein) , they body identify it and produces antibody against it..

Whom it is given?
It is given for infants, workers who are of great risk of getting HBV including us medical students..

What about Oman?
This vaccine is included in the EPI ( extended program of immunization) in 1990 , so if u r born before this yr and u r a risk group u better be vaccinated..

How much Oman achieved from this vaccine?
I don’t have a graph but I got figures:
In 1995: number of new cases were 622 and in 2001 it became 57…
This shows how great is the HBV ..

New science
The HBV vaccine is made by DNA recombinant techniques and now they are trying to build a DNA vaccine .. still under studies.

Hepatitis B is unlike any other infection for which a successful immunisation programme has been developed. untl now immunisation programmes have been directed against micro-organisms cuz of acute manifestations of the infections they cuz.
The presently available Hip B vaccines are safe immunogenic and effective.

The major goal of HBV vaccination is the prevention of chronic diseases associated with the carrier state , rather than the prevention of acute hepatitis or HBV infections per se.
The situation in Oman:
Hepatitis B immunisation has been integrated into the existing EPI schedule with effect from August 1990.

Only newborns , born on or after 1st august 1990 have received the vaccine.
Family contacts of carriers & cases of Hep.B who r below 10 years and negative screening for HBV infection are also given the vaccine.
Medical personals are also included.
The youngest the individual when acquired the infection the higher the risk of being a carrier for HBV.

Well let us come back to immunizations..
Emm we taked about BCG, OPV, HBV and now we wil talk about DPT

What is DPT? It stands for diphtheria, pertussis and tetanus,, together they are called the triple vaccine..

What is diphtheria?
It is an infection caused by Corynbacteria diphtheria , which affect the throat and lead to of a thick fuzzy, gray or black membrane which can cause difficulty in breathing,,
Plus this bacteria produces a toxin ( poison) which damages the heart and central nervous system… it can cause squint ( diplopia = double vision)
Soo it can be fatal within 24 hours.

What about pertussis?
Su3aaal al-deeki, whooping cough, this is a bacterial infection, which affect the throat and it has three known stages.. which started first like a common cold with sneezing then after 1-2 weeks it causes a typical cough ( whooping) ends with vomiting , then these cough diminishes..

What about tetanus?
Caused by clostridium tetani,, this infection is most likely occur when there is a deep wound .. this produces a neurotoxin causes the muscles to be contarcted…

Lets talk about vaccines now
Diphtheria vaccine?
This vaccine is made from the toxin which the diphtheria produces but after weakening it thus it will not called toxin but a toxoid ..

Recommendation of diphtheria vaccine?
It should be given during in the immunization program, plus booster dose should be given every 10 years.. thus be sure the child get the booster dose before entering school and leaving it at age 15-19 yrs old.. also people close contact with diphtheria patients..

What are its side effects?
It can cause redness or pain around the site of injection , mild fever.. other sever complication but rae include: allergic reaction and seizures.

Pertussis vaccine?
Pertussis vaccine which is used in DPT is a whole cell inactivated vaccine, I mean it is alive bacteria but weak.. thus can cause problem if the child has weak immunity…
In that case , the child should be given DT and instead of the P the child given a special vaccine against pertussis made from parts of the bacteria ( this vaccine called acellular vaccine

Tetanus vaccine?
Is a toxoid , which is a weak tetanus toxin..

Let us talk about numbers
Diptheria cases :
In 1981 ( 10) , 1990 (0), 1995 (0) , 2001 (0).
Pertussis cases :
In 1981 (2236) , 1990 (49), 1995 (108) , 2001 (54).
Tetanus:
In 1981 ( 36) , 1990 (3), 1995 (7) , 2001 (3).

Why pertussis still high?
Theoretically the P vaccine should produces excellent immunity, but it is found its immunity is not life long thus its incidence is higher in adult ..

Good efforts fahad … well done indeed ….

Now let me introduce few immunisation terminology that maybe good to know when reading such important and vital topic .

What are the contraindications for vaccination??
Well… the only contraindication for vaccination is .
if there is an anaphylactic reaction to a vaccine .. this will contraindicate further doses of that vaccine or any anaphylactic reaction to a vaccine constituent contraindicate the use of vaccines containing that substance .
Moderate or severe illnesses with / without fever .
Anything else is not a contraindication for vaccination for a normal child ( not immunodeficient or children under chemotherapy ).

What a bout the immunodeficient children??
Congenitally immunodeficient children should not be immunised with live vaccines ( MMR, OPV, BCG and Yellow fever vaccine ). Children with cancer and children receiving high doses corticosteroids or other immunosuppresive agents should not be vaccinated with live vaccines as well.
These guidelines also applied for children with documented HIV infection.

Active immunisation??
The immunisation provided through vaccination.

Passive immunisation??
The immunisation provided by injecting immune globulin (IG) derived from the serum of immunised individuals.

Children with chronic illnesses ?
Most chronic illnesses are not contraindications to vaccinations.
For premature infants .. they should be immunised according to their chronologic age and not gestational age.

great samy....
keep it up...:)