Children below 2 years of age can now be protected against typhoid fever as the World Health Organization has prequalified Bharat Biotech's Typbar-TCV, the world's first conjugate vaccine for the deadly disease.
Unlike regular shots, typhoid conjugate vaccines can be given to infants older than 6 months. They provide longer-lasting immunity and therefore, require only a few doses.
Being prequalified by WHO means the vaccine has met the organization's standards in terms of quality, safety, and efficacy. Such status allows the product to be available for procurement by agencies under the United Nations such as the United Nations Children's Fund and the GAVI Alliance.
TCVs will soon be for distribution in low-income countries, which WHO describes to be the places with the most exposure to Salmonella Typhi, the strain of bacteria causing typhoid fever.
A funding of $85 million has already been approved by the GAVI Board to acquire Bharat Biotech's vaccine. Its distribution will commence by 2019 and include countries that are not supported by the alliance.
Typhoid Vaccine Testing In India And Oxford
The pharmaceutical company began working on the TCV in 2001, says its founder and managing director Dr. Krishna Ella. His team wanted to create a product out of scratch that would protect a person from ages 6 months to 65 years, a feat that cannot be achieved by older vaccines.
Ella explains that previous vaccines are based on polysaccharides or sugar, which an infant's body cannot recognize as foreign. Hence, it does not produce antibodies that would build immunity against the disease.
TCVs, on the other hand, links sugar with protein to successfully trigger an infant's body by creating antibodies that would provide long-term immunity.
Bharat Biotech first tested its vaccine on 10,000 babies in India. However, the experiment rendered unsuccessful because of the difficulty in measuring progress among its participants.
Subsequently, the company took the Typbar-TCV to Oxford where it studied volunteers who were made to drink water with a high concentration of Salmonella Typhi. A part of the group was given the new vaccine while others were shot with older vaccines and placebo.
The Oxford experiment, which was financed by the Bill and Melinda Gates Foundation, was conducted for Ella to prove his vaccine is effective as Indian companies are often deemed as untrustworthy.
A journal report states that in the human challenge, the company's TCV was 87 percent effective compared with polysaccharide vaccines with an efficacy of only 65 percent.
Symptoms And Complications Of Typhoid Fever
Typhoid fever is commonly spread through contaminated food and beverages, such as water. Its symptoms include high-temperature fevers that last for long periods, stomach pains, headaches, and loss of appetite.
The Centers for Disease Control and Prevention notes that some individuals may experience constipation or rashes. In rare cases, the disease may even bring on internal bleeding and death.
Salmonella Typhi is common in many parts of the world, with the exception of highly industrialized countries including the United States, Canada, Australia, and Japan. Those traveling to Asia, Africa, and Latin America are recommended by the agency to take extra measures for protection.