Typhoid is a bacterial infectious disease that is caused due to lack of proper hygiene and living conditions. It spreads through contaminated water or food.
The main symptoms of Typhoid are high fever, diarrhea and loss of appetite. The presence of Salmonella Typhi (SP1 and SP2) in food or water results in this infectious disease.
It has been estimated that in a year more than 21 million people get infected with Typhoid. The number of fatal cases goes as high as 200000.
According to WHO-SAGE, children under the age of two years account for a large proportion of severe typhoid fever cases.
ABOUT TYPHOID BACTERIA
• This microbe, also known as "Salmonella enterica serotype Typhi," is the cause of the disease.
• It's a gram-negative bacteria with an outer membrane and a thin cell wall.
• The cells are reddish in color, with black stains in the center of some of them.
• It is rod-shaped and grows in the human body's small intestine.
• These bacteria are primarily found in humans.
• This type of species can survive in high-oxygen environments and can also be found in sewage, water bodies, and some even produce their own food.
HOW TYPHOID SPREADS IN HUMAN BODY?
• Bacteria enters the human body through contaminated foods and water, where they then enter the human body's intestinal cells.
• It then spreads throughout the body after passing through the bloodstream and destroying the lymphatic system.
• The white blood cells in the liver and the bone marrow are the main carriers of this bacterium.
• They multiply and re-enter the blood cells there, causing a variety of symptoms to develop in later stages.
SYMPTOMS OF TYPHOID
The common symptoms of Typhoid are:
• High fever
• Skin rashes
• Loss of appetite
• Abdominal pain
• Watery stools
• Severe headache
Antibiotics can be used to treat typhoid bacteria, but the bacteria have developed resistance to a variety of antibiotics.
In India, Bangladesh, and Pakistan, extensive drug-resistant (XDR) typhoid outbreaks have been discovered.
Bharat Biotech, based in Hyderabad, has developed a typhoid vaccine (Typbar TCV) that is more effective than previous typhoid vaccines in preventing typhoid fever.
The World Health Organization's Strategic Advisory Group of Experts (WHO-SAGE) on Immunization has already pre-qualified Typbar TCV as a type of conjugate vaccine.
In India, two typhoid vaccines were used: Polysaccharide Typhoid Vaccine and Live, Weakened Typhoid Vaccine. However, their efficacy is lower than that of the conjugate vaccine, as they only provide 60-70 percent protection, compared to nearly 82 percent for the conjugate vaccine.
In India, the vaccine has been approved for clinical use.
TYPBAR TCV VACCINE
• Typbar TCV is the world's first conjugate Typhoid vaccine that has been clinically proven.
• Since 2017, Bharat Biotech has been supplying Pakistan with the typhoid conjugate vaccine.
• Pakistan is also the first country in the world to include the typhoid conjugate vaccine in its national immunisation programme.
• In children of age 9 months to 16 years, a single dose is effective in preventing typhoid. It builds immunization after two to three weeks of getting the vaccine.
• The vaccine is a conjugate vaccine, which means the antigen is chemically linked to a carrier protein in the vaccine. It's a polysaccharide in this case.
• In Nepal, the vaccine was put to the test.
• The vaccine was found to provoke an immune response in 98 percent of the vaccinated children in a small phase-3 trial conducted in Nepal among two groups of people – 2-45 years old and 6-23 months.
• Healthy adults between the ages of 18 and 60 who had never had typhoid were vaccinated first and then exposed to the bacteria in phase-2 of human trials. The vaccine had an 88% efficacy rate.
• Two other vaccines were tested in the study: polysaccharide typhoid vaccine and live, weakened typhoid vaccine.
• These two are not as effective as Typbar TCV.
• In comparison to Typbar's 88% efficacy, they only show 6-70 percent efficacy.
• Typbar has additional benefits. It can be administered to babies as young as six months, whereas the other two cannot be given to children under the age of two.