 |
Immunization Dialogue Indian Pediatrics 1999;36: 1167-1168 |
Sequencing of Vaccine Doses |
2. If Hepatitis-B vaccine has been given during the intervening period, when should the second dose of Hepatitis-B vaccine be given? 3. Can any inactivated vaccine be given during the intervening period of two doses of live attenuated vaccines? Sumit Kumar, Reply Dr. Kumar has asked 3 specific questions, but there is a common thread running through them. Let me answer the questions and then I shall deal with the common issue. Hepatitis B vaccine can be given during the intervening period between giving BCG and the first dose of oral polio vaccine. Usually BCG is given soon after birth or during the first 2 weeks of life and we can give the first dose of OPV also simultaneously. The WHO has introduced an unsatisfactory term of `zero dose' to this first dose. To say that `zero dose' has been given is in fact an oxymoron (self-contradictory statement). The reason why I bring this issue is to show that HB vaccine also can be given simultaneous with BCG and/or OPV. If you have given BCG at or around birth and if the first dose of OPV is going to be given at 6 weeks, you could give HB vaccine any time during that interval too. However, unless given immediately after birth (within 48, preferably 12 hours) that dose of HBV does not offer protection from vertical HB transmission. Therefore there is no particular advantage in giving it in between, but from technical point of view it is allowed. Similarly, HB vaccine can also be given between 6 and 10 weeks when DPT/OPV doses would be given. If HB vaccine was given on a given day, the second dose is due 4 weeks (or one month) later. In the above case it would again fall between two doses of DPT/OPV. The only live attenuated vaccine we give in multiple doses is OPV; any inactivated vaccine can be given between two doses of OPV. However, I would discourage any injected vaccine, live or inactivated, but particularly any live vaccine (BCG or Varicella) from being given less than one month after a dose of measles or MMR vaccine, unless it was an emergency, such as dog bite and rabies immunization. If OPV is given within one month after giving measles vaccine, I would have no objection, particularly during pulse immunization campaigns. The common thread among all these questions is about immunological interference between doses of different vaccines if given at intervals of less than 4 week. There is only one vaccine (namely, measles vaccine) that may (theoretically at least) interfere with another vaccine, particularly a vaccine that induces cell mediated immunity, if given within about 4 weeks. Such CMI inducing vaccines are the live vaccines of BCG and Varicella, whereas OPV induces predominantly humoral immunity. T. Jacob John, |
Indian Pediatrics 1999;36: 1168-1169 |
If a mother is not Hepatitis B virus carrier, Hepatitis B vaccine can safely be postponed to the second or the third year of life. This will not only reduce the number of injections to an infant, but, also give some financial relief to the parents by stretching the period of high expenditure on vaccines from 1 year to 2-3 years time. Because of the financial constraint many parents forgo either Hib or HB vaccine for their children. With this alternative we can provide proper immunization and restrict the number of injections to five during the first year of life. Yash Paul, References 1. Goel D. How to avoid multiple injections? India Pediatr 1999; 36: 607. 2. John TJ. How to avoid multiple injections. Reply. Indian Pediatr 1999; 36: 607-608. 3. Kumar A, Dutta AK, Saili A, Nangia S, Dutta R. Immunogenicity and tolerance of H. influenzae type b, tetanus toxoid conjugate vaccine given concurrently or in combination. Indian J Pediatr 1997; 64: 839-847. Reply Dr. Yash Paul brings in some new suggestions to reduce the frequency of injecting vaccines to infants. The background has already been described in the earlier dialogue to which he refers. Using liquid DPT to reconstitute lyophilised Hib vaccine is one possibility which was mentioned in the earlier response (to Dr. Deepak Goel). However, only when the manufacturers of the specific products have approved such mixing, should it be practiced routinely. According to the Drugs Controller's guidelines, I understand that such a mixture is a new product and it needs approval before clinical introduction. Specific and limited studies are conducted under careful supervision and the results of such studies can be used to argue a case. The results should not be automatically used routinely. The new suggestion Dr. Yash Paul brings in is to postpone Hepatitis B immunization in infants born to mothers who are already known to be not chronically infected with HB virus. Dr. Yash Paul says that HB vaccination can be `safely' postponed to the second or third year of life. This practice may not be all that safe, since we do know that horizontal transmission of HB virus occurs in infancy, in preschool age and in older children. If there is any member of the family, not necessarily the mother alone, who is with chronic HB virus infection, then the infant is at risk for horizontal transmission. The younger the child, the more the frequency of fondling and kissing by adults, thereby increasing the potential risk. For the unfortunate infant who gets infected, the probability of chronic infection is 90% or more. Therefore I would disagree with this suggestion but argue that HB vaccine must be given at the earliest possible opportunity for the best (or maximum) benefit. If a pediatrician desires to postpone some injections, there are other possibilities. For example, if two doses of DPT are given 2 to 3 months apart, starting at or after 2 months of age, then we could avoid a third dose for the primary series, but we must follow it up with a first booster about 12 months after the second dose. These days where and when diphtheria and whooping cough are infrequent, a few months of delay in protection would hardly matter. The risk of non-neonatal tentanus also is not much in early infancy. Regarding HB vaccine also, if we give two doses one to two months apart, delaying the third dose into early second year may be acceptable in infants whose mothers are not virus carriers. Finally, we can make the injections less traumatic by using 26 or at the most 25 guage needles, especially very sharp ones (disposables are very sharp), and giving injections without shaking the needle while in the skin. In my personal experience, if you befriend the child, or play with the toddler or infant and distract his/her attention, and be `quick on the draw', quite often they do not even cry when injected. Only when you see this in real life, will you get that `conversion experience'. If you have several babies in the clinic, if one cries, the others are already tuned in to cry at the slightest provocation. This situation can easily be corrected. In the case of toddlers and preschoolers, under no circumstance should we allow them to watch our fixing the needle on to the syringe and drawing the vaccine into the syringe. All these increase the anxiety and fear in the child. Parents must be counselled to reduce their anxiety and a reward like immediate breastfeeding for the infant, or a sweet for the older ones soon after an injection can work like magic. T. Jacob John, |
