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| NEWER PERTUSSIS VACCINE |
Acellular pertussis vaccines (aP): The first Acellular pertussis vaccines were developed in Japan. The first DTaP combination was licensed in USA in 1991, initially as an alternative to DTwP boosters but not included in routine childhood vaccination. All aP vaccines contain inactivated pertussis toxin combined with filamentous haemagglutinin and sometimes additional B-pertussis components e.g. fimbrial antigens and pertactin. In large multicentric studies performed recently in Germany, Italy and Sweden, it was proved that DTaP vaccines are significantly less reactogenic than DTwP vaccines in terms of high fever, seizures and hypotonic – hypo responsiveness episodes. A number of aP vaccines are available at present (mostly outside India), either as individual vaccines or DTaP combinations, with or without the addition of Hepatitis-B. Hib or poliovirus vaccine (IPV).
WHO position on pertussis vaccine:
- No causal association has been identified between whole cell pertussis vaccine or acellular vaccines and permanent brain damage or death.
- There is no indication of clinically significant immunological interference between aP and other vaccines simultaneously administered at different site.
- Enhanced surveillance is required to assess the true long-term protection provided by wP as well as aP vaccines.
- In terms of redness and swelling at the site of injection, fever, agitation, prolonged crying, febrile seizures and hypotonic – hyporesponsive episodes, aP vaccine was better than wP vaccines.
- Both vaccines are >80% efficacious in developing protective immunity.
Indications of Acellular pertussis vaccine: It should be considered in children who experienced significant reactions to previous dose of DTwP. These including:-
- Persistent and inconsolable crying for 3 or more hours within 48 hours of vaccination.
- Temperature > 40.5 oC within 48 hours.
- Collapse or shock like state within 48 hours and
- Convulsions with or without fever occurring within 72 hours of immunization with DTwP.
DTaP : It is now available in India. It contains Diphtheria toxoid, Tetanus toxoid and 3 purified pertussis antigens – pertussis toxoid (PT), filamentous haemagglutinin (FHA) and pertactin, adsorbed on aluminum salts, with preservative being 2-phenoxyethanel. 0.5 ml dose contains not less than 30 IU DT, 40 IU TT, 25 µgms of PT, 25 µgms of FHA and 8 µgms of pertactin. It is administered deep intramuscularly and can be mixed with Hib vaccine. Adverse reactions are usually mild and appear within first 48 hours of vaccination. Common side effects seen are mild soreness, erythema, swelling or induration at injection site. In some mild fever may follow. Rarely one may see fatigue, malaise, headache, arthralgia, myalgia, urticaria, anaphylactoid reaction and hypotonic – hyporesponsive episodes and convulsions within 2-3 days of vaccination. Its protective efficacy is 88.7% (Trials in Germany). It should be stored at 2o–8oC and should be discarded if vaccine has been frozen.
Reference:
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Core information for the development of Immunization Policy. WHO- Vaccines and Biologicals. 2002 Update
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Update on Immunization Policies, Guidelines and Recommendation. Indian Pediatrics2004; 41: 239-244.
Last Updated on 05-11-2004 Courtesy Pediatric Oncall
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| DPT/ DT/ TT VACCINE |
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Dr. Nitin Shah
Hon. Pediatrician- UHC, LTMG Hospital, Mumbai.
Treasurer, Indian Academy of Pediatrics, 1998-2001.
[DTP = Diphtheria, Pertussis, Tetanus Vaccine (Triple vaccine)]
[DT = Diphtheria, Tetanus Vaccine (Dual vaccine)]
[TT =Tetanus Toxoid Vaccine]
1.What is DPT given for?
1. DPT is a killed combination vaccine. It contains Diphtheria toxoid, Tetanus toxoid & killed whole cell of Pertussis organism to protect against Diphtheria, Tetanus & Pertussis (whooping cough) respectively.
2. How are DPT/DT/TT available?
2. DPT/DT/TT are available as ready to use liquid in single dose ampoule containing 0.5 ml of vaccine or as multidose bulb containing 5.0 ml i.e. 10 doses of vaccine.
3. How are DPT/DT/TT stored?
3. DPT/DT/TT are stored in refrigerator at 2-8 0 C. They should not be frozen. If frozen by mistake, they should be discarded as on freezing the efficacy goes down & the side effects increase. These vaccines should not be stored in the door compartment.
4. When is DPT given?
4. 3 primary doses of DPT vaccine are given at 4 weeks interval starting at 6-8 weeks of age along with the 3 primary doses of oral polio vaccine. It is an EPI vaccine recommended by Govt. of India for universal immunization. Hence it is recommended routinely for each and every child.
5. When are boosters of DPT given?
5. First booster dose of DPT is given at the age of 15-18 months along with the 1st booster dose of OPV. Govt. of India under EPI recommends only DT as the second booster at the age of 4-6 years whereas Indian Academy of Pediatrics recommends DPT and OPV as the 2nd booster at 4-6 years of age.
6. Why do the recommendations differ from authority to authority regarding 2nd booster dose?
6. Indian Academy of Pediatrics feels that the immunity against pertussis & poliomyelitis will wear off by 5 years as will happen for diphtheria & tetanus. This will lead to increased risk of whooping cough & poliomyelitis in adolescents & adults. In fact pertussis does occur in adolescents & adults, but it may be difficult to suspect & diagnose it at this age. Hence IAP recommends OPV & DPT & not only DT as the 2nd booster at 4-6 years.
7. How is DPT given?
7. DPT is given as intramuscular injection. It should be given over anterolateral aspect of thigh or over deltoid muscle in older child. It should not be given in the gluteal region especially in <2-year-old child.
8. Why are intramuscular injections not given over buttocks?
8. Gluteal region is a potentially soiled area. It is difficult to expose especially in an older child. The sciatic nerve can be aberrant & hence can get damaged even when upper outer quadrant rule is followed while injecting. Lastly gluteal region has a lot of fat space. Hence if injection is not given deep, it can enter the fat space leading to poor absorption especially with hepatitis B vaccine. Fat space also has less antigen presenting cells and hence the immune response is suboptimal.
Anterolateral aspect of thigh has good muscle mass. There is not much fat over it. It is a cleaner part & easily exposed. There are no important neurovascular tissues, which can get damaged. Same is true for deltoid muscle which after 6 months can easily take 0.5-1.0 ml of injected volume. This makes the anterolateral aspect of thigh or deltoid muscle the logical choice for any IM injections including vaccines.
9. What is the efficacy of DPT vaccine?
9. Efficacy of diphtheria toxoid & tetanus toxoid is excellent. The protection is seen in nearly 100% of vaccinees with good long-term protection after primary & booster doses of DPT. The pertussis component is a weak candidate & the protective efficacy is seen in 70-90% of cases. This is one of the reasons why IAP recommends DPT and not only DT as 2nd booster dose at 4-6 years of age.
10. What are the side effects of DPT/DT/TT?
10. The side effects seen following DPT/DT/TT include local side effects and systemic side effects. Pertussis component of DPT also leads to some serious toxicity as discussed in next question.
Local side effects: It includes pain, swelling, redness & difficulty in walking. It is seen in 30-40% of vaccinees. It persists for 24-72 hours & responds to paracetamol. Rarely if the injection has gone into deep fascia there could be swelling & redness of lateral aspect of thigh. Sometimes a nodule forms at the injection site which may persist for several days to weeks. It may soften and form a sterile abscess. It does not merit any treatment except analgesics. If it shows fluctuation, it can be drained.
Systemic side effects: It includes fever, lassitude, anorexia, vomiting, irritability, excessive crying etc. seen in 30 – 40 % of patients. Fever is usually mild to moderate, lasts for 2-3 days & responds to paracetamol
11. What are the severe adverse effects of DPT?
11. Pertussis component of DPT is responsible for severe systemic reactions. It is more common with whole cell pertussis containing DPT (DPwT) than acellular pertussis containing DPT (DPaT). It is not seen with DT or TT. It includes hyperpyrexia i.e. fever more than 105 0 F, excessive crying & screaming spells lasting for more than 4 hours, convulsion occurring within next 7 days, encephalitis in next 14 days, unconsciousness or altered sensorium, hypotonic, hyporeflexic episode (HHE), shock etc. If a patient develops any of those adverse reactions it is a contraindication to further use of DPT & instead only DT should be used. Such reactions should be immediately reported to doctor.
12. What are the contraindications to use DPT?
12. Primary contraindication (i.e. to the first dose of DPT) is presence of progressive neurological disease like the primary metabolic disorder that affects brain. This of course is rare in clinical practice. Static brain lesions like cerebral palsy, febrile seizures, epilepsy etc are not a contraindication to use of DPT. In patients with epilepsy it is better to control convulsion with drugs so that blame should not go to DPT should a convulsion occur. In febrile seizures patients should be told about fever prophylaxis.
Secondary contraindication (i.e. to further doses) of DPT includes development of severe adverse reactions as discussed above following previous DPT injection.
History of severe adverse reactions to DPT in a child by itself is not a contraindication to its use in siblings.
13. What is the treatment of side effects following DPT?
13. Paracetamol or ibuprofen can be used to treat pain, swelling, redness, difficulty in walking and fever. It takes 2-3 days for the symptoms to disappear. In case abscess has formed, treat with antibiotics and drainage. Persistent nodule should be left alone, as it does not lead to any other symptoms. Patients developing severe adverse reactions should be admitted & kept for observation & treated symptomatically.
14. What if the patient comes late for vaccination?
14. Tetanus can occur at any age. Diphtheria usually occurs in first 10 years of life. Pertussis usually occurs in 1st five years of life. Hence if a patient comes late he should still be given 3 doses of DPT if he is less than 5 years, 3 doses of DT if he is 5-10 years & only TT if he is >10 years old. He would also receive a booster of DPT 1 year after the 3rd primary dose & 2nd booster 3-4 years after the 1st booster if he is still <5 years young. He will receive DT as booster if he is 5-10 years old.
15. What if subsequent dose is delayed?
15. As DPT/DT/TT induce T cell memory response it is not necessary to restart the schedule. It is enough to just complete the age appropriate remaining doses.
16. Can DPT be given along with other vaccines?
16. DPT can be given along with any other vaccines. In fact it is given along with OPV, Hepatitis B & Hib vaccine. A combination vaccine containing DPT + Hib and DPT + Hepatitis B are available. Other combinations available abroad include IPV + DPT + Hib, DPaT + Hib and IPV+ DPT + Hib + Hepatitis B.
17. What is acellular pertussis DPT vaccine?
17. As seen before, the severe adverse side effects seen with DPT are due to pertussis component. In fact some countries like UK reverted to only DT in past due to the fear of side effects. This strategy led to widespread epidemics of pertussis, which had severe morbidity & even mortality especially in infancy. Hence it is clear that pertussis vaccine is required to be given routinely. The question is can the side effects be decreased by modifying pertussis vaccine. It was realized that the reactions were due to components of cell wall of pertussis organism, which are not required for efficacy of vaccine. So people tried using only the antigens of pertussis organism like the pertussis toxin filamental antigen, FHA, 69 KD protein etc. All of them proved as immunogenic as whole cell DPT with remarkably lesser side effects. This vaccine is called acellular pertussis vaccine, as it does not have whole cell wall of pertussis. Acellular pertussis DPT is available abroad & is routinely used for both primary doses and for boosters. It will be soon available in India for use as boosters.
18. What about DT? When is it used?
18. DT has same amount of diphtheria toxoid & tetanus as DPT but does not have pertussis component. It is also called as dual vaccine. The availability, storage, efficacy, method & route of administration are same as DPT. Side effects are similar to DPT. It is given as 2nd booster at 4-5 years under EPI. (IAP recommends DPT as 2nd booster). It is also used in patients where pertussis component is contraindicated.
18a. What is dT vaccine?
18a. dT vaccine has 1/10th dose of diphtheria toxoid than present in DT/DPT. If full dose of diphtheria toxoid is given as present in DT/ DPT in children above 10 years of age, it can lead to serious side effects like cardiac toxicity, serum sickness like reactions etc. With lack of natural boosting due to mass vaccination, diphtheria can occur beyond 10-15 years of age in vaccinees. One needs to give booster of diphtheria at 10 years and maybe every 10 years thereafter to maintain protective titres. dT is useful in such cases as a booster at 10 years (instead of TT). It is not yet recommended in India and is neither available.
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| TETANUS TOXOID (TT) |
19. What about TT?
19. The storage, availability, efficacy & method of giving TT is the same as for DPT. Even side effects are similar to DPT except that is does not lead to severe adverse effects as seen with DPT.
20. When is TT routinely used in children?
20. TT is routinely used for children >10 years of age as they do not need both Diphtheria & pertussis components. It is given as a booster dose at 10 years & 16 years to children who have received their primary doses/boosters of DPT/DT before. It can be then taken every 5-10 years to maintain protection life long
21. When is TT given to pregnant women?
21. A lady who is previously unimmunised should receive 3 doses of TT during pregnancy at 1-month interval starting the first dose at 28 weeks. The last dose should be at least 30 days prior to the expected date of delivery so that there is enough time for good antibody titres to develop in mother & for it to be passed on to the fetus transplacentally to prevent neonatal tetanus. During repeat pregnancy, 2 doses of TT are given at 4 weeks interval. Again the last dose is given at least 30 days before delivery.
22. When is TT given to an adult with injury?
22. An adult who has never received or has received incomplete course of TT before in life should be given 3 doses of TT at 4 weeks interval followed by a booster after 1 year & then every 5 years. If he then develops any injury or requires any surgery there is no need to take anymore TT as he is protected in between the doses. If such an adult has taken the last TT beyond 4-5 years in past, he can be given one dose of TT, which acts as a booster. It is neither required nor desirable or safe to give TT for each and every injury every now & then in such a protected person.
23. What if the child gets injured, should he receive TT?
23. A child who has received 3 primary doses of DPT/DT is protected till 15 months of age & does not need TT. If he is 15-18 months of age he should receive his first 1st booster of OPV + DPT which will also boost up anti-tetanus immunity. Such a child is protected till 4 years & does not need a TT till that age. If he is between 4-6 years he should receive his 2nd booster of DT or OPV + DPT which will boost up his anti-tetanus immunity too. Such a child is now protected till 10 years of age. After this a booster of TT is given at 10years, 16 years & every 5 years thereafter. In between such doses there is no need to give TT for injury.
24. What harm is done if one gives TT frequently?
24. TT is a very strong & potent antigen & induces strong antibody titre. If TT is given frequently, it will hyper-immunize the patient. Such a patient can develop arthus like phenomenon with development of fever, rash, joint pain, joint swelling etc. Hence it is not desirable to give frequent injections of TT in an otherwise immunized patient as it is not only unnecessary, but is even dangerous at times.
25. Should a patient who recovers from diphtheria or tetanus or pertussis receive vaccine against the respective disease?
25. Neither diphtheria, tetanus or pertussis disease leads to strong immunity. Hence, a person who has recovered from such diseases should receive 3 primary doses and boosters of DPT/DT/TT as appropriate for his age.
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Last created on 23-02-2001
Last updated on 01-11-2004
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How to cite this url |
Dr.Shah N.Diphtheria, Pertussis and Tetanus DPT vaccine.Pediatric Oncall [serial online] 2004 [cited 2004 November 1];1. Available from:
http://www.pediatriconcall.com/fordoctor/diseasesandcondition/
immunization_vaccination/Dpt.asp
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