Why JE vaccination failed to impact?

Vaccination is the mainstay of prevention strategies for Japanese encephalitis – the child killer disease that recently caused many deaths in Gorakhpur, Uttar Pradesh. This article discusses why the vaccine drive in India has failed to reach its full potential in the fight against the disease, and what can be done about it.

Japanese encephalitis (JE) has been in the headlines recently due to the deaths of a large number of children at BRD Medical College in Gorakhpur, Uttar Pradesh (UP)...JE is not new in Gorakhpur, or for that matter, in UP. It has been there since 1978, when the first major outbreak occurred in the state, during which 3,550 cases and 1,117 deaths were reported from 40 districts....

Currently available JE vaccines in India
Currently, there are three vaccines available in India. Two are manufactured by Indian companies, while another is imported from China and is exclusively used in the Universal Immunization Programme (UIP) of the Government of India.

These vaccines are briefly described below:
JENVAC®: This vaccine is manufactured by Bharat Biotech International Ltd., a Hyderabad-based company. It is an inactivated (killed) Vero-cell derived vaccine prepared from an Indian strain of JEV. Data from a two-dose study showed that a single dose of the vaccine was sufficient to elicit the immune response as the subjects who received a single dose were 98.67% seroprotected (Bharat Biotech). It is priced at Rs. 990 per piece (Indiamart).

JEEV®: This vaccine is manufactured by Biological E Ltd., based in Hyderabad. It is a purified inactivated (killed) vaccine that uses the SA 14-14-2 strain of JEV. It is a two-dose vaccine and the primary immunisation is given four weeks apart (Biological E). It is priced at Rs. 985 per piece (Indiamart).

SA 14-14-2: This vaccine is manufactured by the Chengdu Institute of Biological Products, China. It is a live-attenuated vaccine that is manufactured as per the World Health Organization (WHO) guidelines for production of live JE vaccines for human use.

This is a single-dose vaccine that has been licensed for use in China since 1988. Till date, over 400 million doses have been administered in China and other Asian countries, with a brilliant safety record... A major advantage of this vaccine is that it is inexpensive (Rs. 10 per dose; information obtained through personal communication) and hence is ideal for mass vaccination campaigns (Bharati and Vrati 2009).

What are the causes of vaccine failure?
The Government of India has made vaccination against JE part of the routine immunisation under the UIP in 206 JE-endemic districts in the country (Ministry of Health and Family Welfare, 2015). In spite of this, the JE vaccine has failed to reach its full potential.

The major causes of vaccine failure are briefly discussed below:
Low vaccine coverage: In spite of vaccine immunisation efforts, vaccine coverage is low. A recent ICMR (Indian Council of Medical Research) study (Murhekar et al. 2017), which included 840 children (210 from each of four districts in UP) indicated that the JE vaccine coverage for two doses in Gorakhpur division was only 42.3%.

Thus, although three of four children aged 25-36 months in Gorakhpur division received the first dose the coverage for the second dose was significantly lower. The major reason for this is that the vaccinators were not aware that the second dose of JE vaccine could be given simultaneously with other UIP vaccines like measles and DPT (diphtheria, pertussis, tetanus).

Poverty: Since many of the patients come from the economically weaker section of the society, often leading a hand-to-mouth existence, taking a child for vaccination would mean losing a day’s wages. Hence, this can have an indirect impact on a vaccination campaign.

Malnutrition: Malnutrition goes hand-in-hand with poverty. Malnourished, poor children therefore are likely to have a much weaker immune system than their healthy counterparts. This translates into a weaker immune response and thereby reduced protection against the pathogen.

Lack of health awareness: Lack of health awareness is a major factor behind vaccination failure. Moreover, illiteracy can encourage rumour-mongering that can have devastating effects on vaccination campaigns.

For example, rumours among the uneducated that a vaccine could cause disease or lead to sterility, could severely cripple a vaccination drive. Of importance is the fact that since vaccination campaigns occurs during periods when epidemics do not occur, most people fail to understand why they need a vaccine – which they perceive as an injection for treating a disease – while they are healthy and disease-free.

What can be done?
Training of vaccinators: There is a need for training vaccinators about the correct vaccination schedule, and removing their misconception about administering JE vaccines simultaneously with the measles and DPT vaccines included in the UIP.

Door-to-door vaccination campaign: A door-to-door JE vaccination campaign would increase the vaccine coverage appreciably. However, the feasibility of this approach in terms of implementation costs, availability of manpower, among other factors, needs to be carefully assessed prior to implementation.

Overcoming malnutrition: The nutritional status of Indian children is very poor. A staggering 48% of children below five years of age are undernourished (height-for-age) (Drèze and Sen, 2013). The Midday Meal scheme is a Government of India initiative for ensuring freshly-cooked hot meals for school children with the aim of improving the nutritional status of school-age children, which is a commendable effort.

Creation of health awareness: There is a need for creation of health awareness among the masses, so that they can fully utilise the – often scarce – health facilities currently available in the public sector. Increased advocacy and community participation during vaccination campaigns will generate demand for vaccines and thereby increase vaccination coverage.

Increasing vaccination coverage is easier said than done. It is extremely difficult to implement a vaccination policy, given the multifaceted problems – some of which have been discussed here – at the grassroots level.

In order to overcome these hindrances, there is a requirement for pragmatic planning and development of guidelines that are both practical and implementable for vaccinators, in order to effect observable changes at the ground level. "Reprinted with permission from Ideas for India (www.ideasforindia.in)"

By Dr Kaushik Bharati