World Immunization Week 2024: Humanly Possible — Saving lives through immunization
What is immunization ?
Immunization is a global health and development success story, saving millions of lives every year. Vaccines reduce risks of getting a disease by working with your body’s natural defenses to build protection. When you get a vaccine, your immune system responds.
What are vaccines?
Vaccines contain weakened or inactive parts of a particular organism (antigen) that triggers an immune response within the body. Newer vaccines contain the blueprint for producing antigens rather than the antigen itself. Regardless of whether the vaccine is made up of the antigen itself or the blueprint so that the body will produce the antigen, this weakened version will not cause the disease in the person receiving the vaccine, but it will prompt their immune system to respond much as it would have on its first reaction to the actual pathogen.
How vaccines work
A pathogen is a bacterium, virus, parasite or fungus that can cause disease within the body. Each pathogen is made up of several subparts, usually unique to that specific pathogen and the disease it causes. The subpart of a pathogen that causes the formation of antibodies is called an antigen. The antibodies produced in response to the pathogen’s antigen are an important part of the immune system.
Each antibody in our system is trained to recognize one specific antigen. We have thousands of different antibodies in our bodies. When the human body is exposed to an antigen for the first time, it takes time for the immune system to respond and produce antibodies specific to that antigen. In the meantime, the person is susceptible to becoming ill. Once the antigen-specific antibodies are produced, they work with the rest of the immune system to destroy the pathogen and stop the disease.
Antibodies to one pathogen generally don’t protect against another pathogen except when two pathogens are very similar to each other, like cousins. Once the body produces antibodies in its primary response to an antigen, it also creates antibody-producing memory cells, which remain alive even after the pathogen is defeated by the antibodies. If the body is exposed to the same pathogen more than once, the antibody response is much faster and more effective than the first time around because the memory cells are at the ready to pump out antibodies against that antigen.
This means that if the person is exposed to the dangerous pathogen in the future, their immune system will be able to respond immediately, protecting against disease.
Why do we need vaccines ?
When someone is vaccinated, they are very likely to be protected against the targeted disease. But not everyone can be vaccinated. People with underlying health conditions that weaken their immune systems (such as cancer or HIV) or who have severe allergies to some vaccine components may not be able to get vaccinated with certain vaccines. These people can still be protected if they live in and amongst others who are vaccinated. When a lot of people in a community are vaccinated the pathogen has a hard time circulating because most of the people it encounters are immune. So the more that others are vaccinated, the less likely people who are unable to be protected by vaccines are at risk of even being exposed to the harmful pathogens. This is called herd immunity.
We now have vaccines to prevent more than 20 life-threatening diseases, helping people of all ages live longer, healthier lives. Immunization currently prevents 3.5–5 million deaths every year from diseases like diphtheria, tetanus, pertussis, influenza and measles.
Vaccines are critical to the prevention and control of infectious disease outbreaks. They underpin global health security and will be a vital tool in the battle against antimicrobial resistance.
Who can be vaccinated?
- Children from birth to 18years
- Adults from 19yrs and older
- Pregnant women
- Travelers
Reasons why we should keep up with immunization program despite herd immunity
The Covid-19 pandemic, associated disruption and Covid-19 vaccination efforts strained health systems in 2020 and 2021, resulting in dramatic setbacks. However, from a global perspective recovery is on the horizon — in 2022 diphtheria-pertussis-tetanus (DTP) immunization coverage, albeit unevenly between countries, has almost recovered to 2019 levels.
Measles, because of its high transmissibility, acts as a “canary in the coalmine”, quickly exposing any immunity gaps in the population. Still, 22 million children missed their routine first dose of measles vaccine in 2022, compared to 19 million in 2019.
The following links below shows the schedule for each age range
During and after pregnancy: https://www.cdc.gov/vaccines/pregnancy/vacc-during-after.html
From Birth: https://tools.cdc.gov/medialibrary/index.aspx#/media/id/270536
7 years to 18 years: https://tools.cdc.gov/medialibrary/index.aspx#/media/id/270534
Travelers: See Traveler’s Health for additional tips.
By Damilola Ilori
REFERENCES
World Health Organization (WHO). (2023, December 13). Vaccines and immunization. https://www.who.int/health-topics/vaccines-and-immunization
World Health Organization (WHO). (2023, September 26). How do vaccines work? https://www.who.int/news-room/feature-stories/detail/how-do-vaccines-work
Centers for Disease Control and Prevention (CDC). (2023, August 31). Vaccination During Pregnancy. https://www.cdc.gov/vaccines/pregnancy/index.html
World Health Organization (WHO) AFRO. (n.d.). Immunization. https://www.afro.who.int/health-topics/vaccines
