Study Links Late TB Jab to Ill Health

June 2, 2015

By Otiato Guguyu, via Daily Nation

A delay in vaccinating children against tuberculosis in slums is reducing the effectiveness of the vaccine, according to a new research.

The study published by the Africa Population and Health Research Center shows that underweight children in Nairobi slums get their tuberculosis vaccine very late.

Babies weighing below 2,000 grammes received the vaccine eight times later than those born weighing over 2,500 grammes, says the study titled Effects of Low Birth Weight on Time to BCG Vaccination in an Urban Poor Settlement in Nairobi.

“When immunisation is delayed, there is an increased risk or severity of infections during infancy due to the shortening of the duration of the protective effect of the vaccines,” says the study.

If vaccination is delayed for too long, it could have negative consequences, especially if the infant is exposed to tuberculosis before getting the Bacillus Calmette-Guérin (BCG) jab, says the report.

About nine million new cases of TB were diagnosed in 2013 globally, with 1.5 million deaths reported. Most of the cases and deaths occurred in low and middle income countries.

Kenya is among the 22 high burden TB countries, with an estimated incidence rate of 268 cases per 100,000.

The World Health Organisation recommends that the BCG vaccination should be given at birth, with the exception of HIV-infected infants, in whom the vaccine is associated with safety concerns.

Babies born before their due date are also excluded from this policy. The WHO recommends that they be given the vaccine at 40 weeks.

The Health ministry, however, recommends that pre-term and underweight infants should be immunised at the time of discharge from the hospital irrespective of their weight.

According to the research that was done in Korogocho and Viwandani slums, children born weighing under 2,000 grammes in poor areas get the TB jab on their 34th day.

Those weighing more but less than the 2,500g benchmark get vaccinated on their sixth day, on average, while those weighing above 2,500 grammes get vaccinated on their fourth day.