Vaccines play a major role in preventing and eliminating infectious diseases. The World Health Organization (WHO) considers that immunization is among the most cost effective of health investments. An initiative by WHO helped the world to eradicate diseases like small pox and polio. Now, measles is one of the most dreaded diseases that the country is facing.
Being highly contagious, measles can be transferred to others. Many countries have regular vaccination of susceptible population in order to build herd immunity and thereby successfully interrupting the transmission of the disease. Three of four children who died of measles across the globe in 2008 were from India. Even though there is substantial vaccination coverage, some States like Uttar Pradesh, Bihar and Rajasthan need more attention in terms of immunization coverage.
A cost effective and efficient vaccine is available for measles in the market and it meets the technical criteria for global eradication of the disease. Though, there are a few mild side effects of this vaccine like fever, rash etc, they are observed only in 2 to 3 per cent of the children vaccinated. Very rarely febrile seizures, encephalopathy, acute anaphylaxis have been reported and any severe reaction appears within 30 minutes.
Adverse event occurrence
As the number of vaccines administered is increasing, there is a growing concern about adverse events and reactions. The controversy surrounding measles vaccine is symbolic of public concerns and perceptions regarding the safety of the vaccine. There are many reasons involved in executing a successful vaccination campaign. Quality of the vaccine is one aspect but there are other issues related to reconstitution, administration, storage and use of contaminated syringes and needles. Toxic shock syndrome (TSS) occurs due to contaminated vaccine. Usually multi-dose vials of the measles vaccine is procured by the national Universal Immunization Programme (UIP) for routine immunization.
Measles vaccine is reconstituted with the diluent supplied along with the vaccine just before immunization. In case the vaccine is diluted with contaminated syringes and needles and/or stored for more than stipulated time, lbacteria such as Staphylococcus aureus multiply and release exotoxin. If the contaminated vaccine is administered to children, they develop symptoms such as fever, vomiting, diarrhoea, shock and finally death within 24 hours. These events are described as toxic shock syndrome and the adverse event is associated with vaccine but not related with quality of vaccine.
In some of the incidents, measles vaccine could be reconstituted with similar looking drugs such as muscle relaxants etc. In such cases the infants administered with such type of vaccine died with in a few minutes showing symptoms of breathlessness, seizures, frothing etc. Vaccination of under aged children and children with concomitant virulent infections are also vaccinated with out proper medical examination by medical practitioner. In such cases there is an increased possibility of severe adverse event occurrence.
However, what is observed that the vaccine is usually blamed for the several adverse events. It is understood that investigations into the recently occurring adverse events in Tamil Nadu (April 2008, where four infants are died), Maharashtra (September 2008, where seven infants are died), Assam (in 2008, where 4 infants are died), Madhya Pradesh (March 2010, where two infants are died), Uttar Pradesh - Mohanlalganj (Aug 2010, where four infants are died), Ghaziabad (September 2010, where two infants are died), all have concluded that there was no problem with the vaccine quality. What is of concern is that almost entirely, the adverse events were due to poor storage and distribution, not following instructions on safe usage, mix up of diluents etc., all attributable to “programme error”. In some cases, infants dying almost instantaneously can only be attributable to some mix up of diluents.
Deal with adverse event cases
In mass vaccination programmes, there is a need for strict adherence to the good vaccine administration practices. In addition, trained medical personnel with adequate supply of emergency medicines and equipment are required to deal with adverse event cases appropriately.
It must be understood that when an adverse event happens, the whole immunization programme suffers, as the lay public develop apprehensions about the safety of immunization. It is not surprising therefore that our immunization coverage levels are very poor.
This situation calls for urgent measures to bring sound programme administration practices in the field. The specific areas which need to be immediately addressed are:
Proper training of medical personnel in understanding adverse events and handling such events.
- Cold chain maintenance of vaccine.
- Proper reconstitution methods of lyophilized vaccines.
- Importance of usage and proper storage of reconstituted vaccine.
- Medical examination of children before vaccination.
- Availability of emergency medication such as adrenaline etc.
- Vaccination under medical supervision
- Vaccination to be undertaken where emergency medical facilities are available
- Keep vaccines under observation for 30 minutes following vaccination.
It is ironical that a country like India, which boasts of being a major supplier of paediatric vaccines to the world though UNICEF, PAHO and also direct exports, should itself have a poor record of immunization and worse still, a continuing situation of regular adverse events in the field, all attributable to “programme errors”. It is time that the government woke up to this reality and set its house in order, carry out a detailed assessment of the dysfunctional elements in its immunization programme and take steps to make our immunization programme far more effective.
(The author is with Bhandarkar Children Hospital, Panvel, Navi Mumbai)