Pneumococcal 13-valent Conjugate Vaccine

Subject – Science and Tech

Context – Nationwide PCV drive launched

Concept –

Union Health Minister Dr. Mansukh Mandaviya launched a nationwide expansion of Pneumococcal 13-valent Conjugate Vaccine (PCV) under the Universal Immunisation Programme (UIP) as a part of ‘Azadi ka Amrit Mahotsav.
It was for the first time in the country that PCV would be available for universal use. Pneumonia was a leading cause of death among children under five, globally and in India.
“Pneumonia caused by pneumococcus is the most common cause of severe pneumonia in children. Around 16% of deaths in children occur due to pneumonia in India.

About the vaccine –

It prevents pneumococcal disease. It can protect both children and adults from pneumococcal disease.
The vaccine is a mix of several bacteria of the pneumococci family, which are known to cause pneumonia—hence ‘conjugate’ is included in the name of the vaccine.
Conjugate vaccines are made using a combination of two different components.

Pneumococcal disease –

Pneumococcal disease is a name for any infection caused by bacteria called Streptococcus pneumoniae or pneumococcus. Most people carry pneumococcus in their nose and throat, where the bacteria do not cause any symptoms.
However, sometimes the bacteria grow and spread to other parts of the body and that’s when people become sick.
These bacteria can cause many types of illnesses, including pneumonia, which is an infection of the lungs. Pneumococcal bacteria are one of the most common causes of pneumonia.
Besides pneumonia, pneumococcal bacteria can also cause:
- Ear infections.
- Sinus infections.
- Meningitis (infection of the tissue covering the brain and spinal cord).
- Bacteremia (infection of the blood).
Doctors consider some of these infections “invasive”. Invasive disease means that germs invade parts of the body that are normally free from germ.
Anyone can get pneumococcal disease, but children under 2 years of age, people with certain medical conditions, adults 65 years or older, and cigarette smokers are at the highest risk.
Most pneumococcal infections are mild. However, some can result in long-term problems, such as brain damage or hearing loss. Meningitis, bacteremia, and pneumonia caused by pneumococcal disease can be fatal.

Universal Immunization Programme

It was launched in 1985 to prevent mortality and morbidity in children and pregnant women against 12 vaccine-preventable diseases.
Under UIP, free of cost vaccination is provided against twelve vaccine-preventable diseases i.e. Tuberculosis, Diphtheria, Pertussis, Tetanus, Polio, Hepatitis B, Pneumonia and Meningitis due to Haemophilus Influenzae type b (Hib), Measles, Rubella, Japanese Encephalitis (JE) and Rotavirus diarrhoea.
The programme is one of the largest health programmes in the world. Despite being operational for many years, UIP has been able to fully immunize only 65% of children under 1 year of age.

Conjugate vaccine

A conjugate vaccine is a type of vaccine which combines a weak antigen with a strong antigen as a carrier so that the immune system has a stronger response to the weak antigen.
Vaccines are used to prevent diseases by invoking an immune response to an antigen, the foreign part of a bacteria or virus that the immune system recognizes.
This is usually accomplished with an attenuated or dead version of a pathogenic bacterium or virus in the vaccine, so that the immune system can recognize the antigen later in life.
Many vaccines contain a single antigen that the body will recognize.
However, the antigen of some pathogenic bacteria does not elicit a strong response from the immune system, so a vaccination against this weak antigen would not protect the person later in life. In this case, a conjugate vaccine is used in order to invoke an immune system response against the weak antigen. In a conjugate vaccine, the weak antigen is covalently attached to a strong antigen, thereby eliciting a stronger immunological response to the weak antigen. Most commonly, the weak antigen is a polysaccharide that is attached to strong protein antigen. However, protein and protein/protein conjugates have also been developed.