Germs! How Do We Fight Them Off?

Have you ever wondered why getting vaccinations before traveling on a big adventure is important? Well, it all starts with germs, like bacteria and viruses, that can enter our bodies and make us sick. Such dangerous germs are called pathogens. More specifically, pathogens cause infectious diseases. Luckily, our bodies have a group of cells and substances ready to battle any pathogen that launches an attack against us. These cells and substances work together and are called the immune system. The first time you are infected by a pathogen, your body will have a slow response. However, if you are infected a second time with the same pathogen, the immune system’s response will be quicker because it remembers the pathogen from the first infection. Sometimes the immune system is not strong enough to fight off the pathogens that attack the body, causing people to become sick.

Infectious diseases can be spread between people through liquids like saliva, objects like door handles, or tiny drops in the air created by people sneezing or coughing. Infectious diseases can also spread to humans from insects, animals, food, or water. When you get an infectious disease, you may feel sick, have a fever, be tired, or have achy muscles. One way to keep yourself safe and prevent the spread of diseases is through vaccinations.

What are Vaccines and How do They Work?

Vaccines are helpful in preventing disease caused by pathogens. Vaccines contain harmless pieces of pathogens, or sometimes a weakened form of a pathogen, along with a substance that stimulates the immune system to make the cells stronger and better able to stop infection. Vaccines build up the cells and substances in your body that are specific for a pathogen, so you can fight off that infectious disease (Figure 1) [1]. After vaccination, your body can recognize the pathogen if you encounter it again. Because of the immune system’s memory, the response will be stronger and quicker than it was to the vaccine.

Depending on the pathogen, some vaccines may need multiple shots before the body can adequately recognize and defend itself against the disease. For example, you need to get three shots of the Hepatitis B vaccine, whereas you only need one shot for the Yellow Fever vaccine [1]. Everyone’s doctor will give them different advice on which vaccines they should get, depending on their age, health, travel plans, and where they live.

Why Do Diseases Spread So Quickly These Days?

One of the reasons that diseases can quickly spread worldwide is because of globalization [2, 3]. Imagine you have family members who live in another country. You could get on a flight to visit them—something people could not do 100 years go. That is what globalization means—the connectedness of people, companies, and governments all over the world. These connections continue to become easier and faster due to planes, trains, and automobiles. Although globalization is a wonderful thing, there are also some negatives. Global connectedness allows diseases to travel quickly, too. Spread of infectious diseases can lead to international health emergencies. Remember when the COVID-19 pandemic began? It spread everywhere around the world quickly!

Places where lots of people spend time in a small area have an increased risk of diseases spreading quickly [3]. Such places include workplaces, homes, or public spaces where people are physically closer together. Both globalization and the tendency of people to spend time together contribute to the spread of infectious diseases that impact people all over the world. As a result, we need to find solutions to improve our environments and protect ourselves from the risk of infectious diseases. COVID-19 also highlights the importance of vaccines in stopping the spread of germs and keeping us safe from serious illnesses [3]. As people travel more and connect with others globally, it is important to consider how you can keep yourself and others safe. One step you can take is to get travel vaccinations.

Travel Vaccinations

Remember that getting sick while traveling not only affects the people who are traveling—it also impacts the people who live in the places we travel to and our communities back home. That is why people may be recommended or required to get vaccinated when they travel. Travel vaccinations are particularly necessary for people who are more likely to get sick, such as older adults, pregnant women, and babies. The cool thing about vaccinations is that the more people who are vaccinated, the less likely pathogens are to spread globally.

It is suggested that travel vaccines be given at least 2 weeks before leaving (Figure 2) [4]. Most vaccinations are given by nurses or doctors. A personal vaccine plan is necessary based on a person’s travel destination, previous vaccines, and health status [4]. Certain countries may require specific vaccines for entry and travelers should review and follow these recommendations.

Vaccines are only one part of stopping the spread of disease. Other factors, such as avoiding mosquito bites and handwashing, are still important while traveling. Some diseases impact many people around the world but do not have vaccinations available yet, such as Zika virus [4]. Scientists are working hard to create vaccines against these pathogens.

Let us look at one specific travel vaccines that you may run into. The pathogen named Vibrio cholerae causes a disease called cholera in humans. Cholera can spread through drinking water or eating food with the pathogen in it [4]. If it is not treated, people with cholera can have diarrhea, vomiting, and dehydration, and symptoms may be bad enough that they may need to go to the hospital [4]. Luckily, there is a vaccine to help prevent the spread of cholera. Anyone over the age of 5 should get two doses of the cholera vaccine when traveling to high-risk areas [4]. High-risk areas for cholera are places with poor water and bathroom systems (that is why it is also important to fix these problems in the countries that experience them, so everyone can have clean water and stay healthier). The cholera vaccine will give good protection for 6 months, but protection decreases after that [4]. Eventually, if you are traveling to an area of elevated risk again, you may need a booster.

Looking Forward to Your Next Adventure!

Now you can see why it is important for people to get travel vaccinations before a big adventure. Getting vaccinated not only keeps you safe but also helps keep everyone around you healthy. You can make a significant impact in the world by getting vaccinated. However, remember that vaccines are only a small piece of the bigger picture. Improving access to healthcare, creating better living conditions, and keeping our planet green are other ways that we can help prevent the spread of infectious diseases and improve health outcomes for people all over the world [5]. While there are still improvements to be made to protect ourselves and others, do not let this stop you and your adventures to see the world and experience diverse cultures. So, pack your bags, get your vaccinations, and go on some amazing travels!

Glossary

Pathogen: ↑ Tiny living things, like bacteria, viruses, or parasites, that cause diseases in a human or animal.

Infectious Disease: ↑ An illness caused by a pathogen that can spread between people through person-to-person contact, food, water, air, or animals.

Immune System: ↑ The body’s fighters and defense system, which is made up of cells and substances that can fight against germs or pathogens that might harm you.

Vaccination: ↑ A medicine that helps your body develop an immune response to a specific pathogen and protects you from becoming sick in the future when exposed to that same pathogen.

Globalization: ↑ The increasing connectedness of people, companies, and governments across the world, which creates more interactions between individuals globally.

Travel Vaccination: ↑ A vaccine that is recommended or required when traveling to another country to protect you from getting sick and spreading infectious diseases.

Booster: ↑ Another dose of a vaccine you have already received to boost/enhance your protection against that pathogen.

Conflict of Interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.