Written By: Longjam Dineshwori | Updated : October 1, 2020 12:22 PM IST
The DTaP-IPV vaccine is given as one dose to children at 4 to 6 years of age. ©Shutterstock.
Sanofi Pasteur India, the vaccine unit of pharma firm Sanofi, on Wednesday, announced the launch of a booster vaccine for preschoolers to protect them against four major diseases - diphtheria, pertussis, tetanus, and polio.
Booster vaccines are designed to boost the immunity acquired during prior vaccination, the company said in a statement. Its four-in-one (DTaP-IPV) vaccine is named as 'Tetraxim.' By reducing the number of injections, it will help increase comfort and improve vaccination compliance for children and reduce parental anxiety, the company noted.
Sanofi said it currently distributes 63 million doses of Tetraxim worldwide which helps protects school children in over 100 countries.
"It works as a reminder for a child's immune system and can also stop the spread of infection to their siblings and grandparents, making it important to maintain vaccination schedules of preschoolers," PTI quoted Sanofi Pasteur India Country Head Annapurna Das as saying.
A booster shot is an additional dose of a vaccine administered after initial immunization to increase immunity against that antigen back to protective levels. For example, a tetanus booster shot is often recommended every 10 years to prevent the return or contraction of the disease.
The DTaP-IPV vaccine is given as one dose to children at 4 to 6 years of age. This is a booster dose given to children who were immunized against tetanus, diphtheria, pertussis, and polio at a younger age. The additional dose helps strengthen or boost the immune system to give better protection against these diseases, which are serious and sometimes fatal diseases. The vaccine is also provided to older children and adults who need protection against these diseases.
Other routine vaccinations like Influenza, Measles, Mumps, Rubella, Chickenpox, HPV also need boosters. However, not all vaccines need booster shots.
Vaccination increases the levels of antibodies against a certain antigen. Over time these antibodies may decline, leaving your body open to the disease once again. Therefore, for certain diseases, you need a booster shot after an initial vaccination to bring your immunity back to its protective levels. Booster shots can prevent resurgent outbreaks of disease.
Here it's worth recalling Russia's diphtheria outbreak in the early 1990s. Russia first witnessed the diphtheria epidemic during the 1950s, with more children becoming prone to the disease. After a vaccine was introduced in 1958, the number of cases significantly decreased within five years. But a severe outbreak of the disease resurfaced in the 1990s. By 1994, there were almost 40,000 reported diphtheria cases as compared to little more than 1,000 cases in 1990.
In the 1990's outbreak, adults became far more likely to catch the disease. This indicated that the children that were first immunized decades earlier ran low on the antibodies for diphtheria. The outbreak led to the change of the diphtheria vaccination plan and countries across the world started giving booster shots to its people to keep up immunization.
Whether you need a booster dose against disease following a primary vaccination is evaluated in several ways. One way is by measuring the level of antibodies specific to a disease. If the anamnestic response is high even many years after receiving a primary vaccine, there is little to no need for a booster dose. The anamnestic response is the rapid production of antibodies in the blood following the introduction of an antigen to which the subject had previously developed a primary immune response.
What will happen if you receive a booster dose when you already have a high level of antibodies against the disease? This may lead to a reaction called an Arthus reaction, a localized form of Type III hypersensitivity induced by high levels of IgG antibodies, which can cause inflammation. Often the inflammation resolves on its own over the course of a few days. By increasing the length of time between the primary vaccine and the booster dose, you can avoid this condition altogether.
