WHO Approves a Safe, Inexpensive Typhoid Vaccine

A new, highly effective typhoid vaccine — the only one safe for infants — has been approved for global use by the World Health Organization. The approval was given in December but announced Wednesday.

Typhoid fever, caused by Salmonella typhi bacteria in sewage and contaminated food, infects up to 20 million people a year and kills up to 160,000 of them, mostly young children. The disease once killed many Americans — Typhoid Mary was a famous carrier — but is now found mostly in Africa and Asia.

The need for an effective, affordable vaccine has risen urgently as urban slums grow, hotter weather spreads the disease to new regions and the bacteria develop resistance to more antibiotics.

Approval means the new vaccine, named Typbar TCV and made by Bharat Biotech of Hyderabad, India, can be purchased by donors, including United Nations agencies, for use in poor countries. GAVI, the Vaccine Alliance, has earmarked $85 million for doses to be given to children starting next year.

The vaccine now costs $1.50 a dose when purchased for developing countries, and the price will drop to $1 or less if donors order more than 100 million doses, said Bharat’s chairman, Krishna M. Ella. The vaccine has been tested and used in India since 2005.

It gained approval for worldwide use after an unusual “challenge trial” that began in 2015. About 100 healthy volunteers in Oxford, England — many of them students — received the vaccine or a placebo, and then swallowed live Salmonella typhi.

The results, published in the Lancet last year, showed the vaccine to be 87 percent effective in preventing typhoid fever. Those who did fall ill were promptly cured with antibiotics.

Bharat, which makes vaccines against nine other diseases, including one approved by the WHO for polio, is developing immunizations against Ebola, chikungunya, Zika and non-typhoid strains of Salmonella.

Its research is supported by the Bill and Melinda Gates Foundation, the Clinton Health Access Initiative, the Wellcome Trust and other donors.