Vaccine schedules are particularly important for infants and children because the diseases that the vaccines prevent are especially deadly for them. While the number of vaccines given to babies today has increased, worrying some parents, science has shown that the total number of vaccines given today isn’t harmful. Spreading out vaccines on a delayed schedule can be harmful rather than helpful to infants, increasing their risk of becoming sick. To help you make the best decisions about vaccinations, Chapter 11 discusses the myths that surround vaccination and vaccine schedules, especially for young children.
Trying to keep track of vaccination schedules can be complicated. We make it easier by describing which vaccines are required for infants and children at which ages in Chapter 8. We include the same information for adults in Chapter 9. Chapter 10 explains when you or your child should not get vaccinated, due to certain health conditions. Thankfully, these conditions are rare.
Preparing for Potential Vaccine Side Effects
Any substance you put inside the human body has the potential to cause side effects. In most cases, side effects don’t affect everyone, and most side effects aren’t serious or long lasting. But it’s always nice to be prepared for typical side effects, and it’s important to be aware of more serious side effects that necessitate a visit to your healthcare provider. We spell out side effects and what to watch for in Chapter 7.
Rarely, around one in a million or so cases, a vaccine can cause an anaphylactic reaction. This type of reaction can affect many body systems and be life-threatening. Anaphylactic reactions can occur if you have an allergy to one of the ingredients found in the vaccine. If you have known allergies to a vaccine or a possible vaccine component, always check the ingredients on a vaccine’s label before being vaccinated. Anaphylactic reactions can include difficulty breathing, facial swelling, a drop in blood pressure, or loss of consciousness. Most, but not all, anaphylactic reactions occur within a few minutes after receiving a vaccine.
Anaphylactic reactions are a medical emergency and require immediate medical attention. If you’ve had this type of reaction in the past, your healthcare provider may recommend carrying an epinephrine (epi) pen.
Optimizing Your Immune Response
While you can’t prevent all illnesses, you can do your part to keep your immune system as healthy and effective as possible. Getting vaccinated is the number one thing you can do to boost your immune system. Certain lifestyle changes can also help keep your immune system humming.
No, there are no magic bullets, pills, or other easy ways to do this. But Chapter 15 includes information that you may not have realized on ways to keep your immune system healthy, from the effects of smoking and alcohol on your immune system to the benefits of getting enough sleep. We also include info on supplements often taken for good health.
Chapter 2
The (Non) Life of a Virus
IN THIS CHAPTER
Studying the make-up and reproduction of a virus
Looking at common viruses around the world
You’ve probably said, “I caught a virus” dozens of times in your life. And no wonder — so far humans have identified close to 7,000 virus species. We know there are hundreds of thousands more and think there are millions, if not trillions, more. Some viruses infect people; others infect other animals; and still others infect plants, fungi, or even bacteria. (There are even virophages that infect viruses themselves.) Viruses — infective agents that can only reproduce inside another cell — are pretty simple, but what they cause is not so simple. They may cause no symptoms. They may wreak havoc on us. They may cause something in between or go back and forth.
Virus particles (virions) are very small — smaller than we can see with a regular microscope. Yet they still manage to perplex us. Sometimes it even seems like they outwit us. As with any enemy, getting to know what a virus is and how it works is instrumental to thwarting it, and this chapter can help. As you also find out here, some viruses can be prevented by vaccines, while others still evade science’s attempts to prevent them.
There are more viruses than we know out there. As people increase transportation, move into areas with few inhabitants, and have contact with different animals, the world becomes increasingly connected. What may have caused an unknown outbreak in an isolated location that is quickly extinguished can become a large epidemic.
Looking Inside Your Average Virus
A virus is put together like a burrito. The tortilla is the protein shell. The filling is the genetic instructions, or codes in the form of DNA (deoxyribonucleic acid) or RNA (ribonucleic acid). The DNA strands are often but not always double strands; the RNA is usually but not always single stranded. This genetic code is what lets the virus reprogram and take over a cell.
Viruses can’t do anything on their own. That’s why they aren’t considered to be alive. They can’t make copies of themselves on their own. A virion all by itself isn’t enough to make you sick if it can’t get inside your cells. Viruses require what living things have in their cells to do what they do best — make copies of themselves. Once a virus is in a living cell, it’s almost like it is alive; it will turn that cell into a virus assembly machine.
Successful viruses turn our cells into photocopiers, churning out virions — more and more infectious viral particles. When we get sick, say with the flu, the cells in our bodies may produce as many as 100 trillion virions. That’s more than all the stars in the Milky Way.
With all of these copies, there are bound to be mistakes. Viruses make lots of mistakes. They often don’t copy their genetic material exactly the same each time. These miscopies are called mutations. Not all mutations are bad; many are dead ends. Headlines may say that a virus is mutating, but that’s just what viruses do. Viruses mutate; birds fly. Mutations, especially collecting over time, can lead to different variants or strains, and sometimes these changes can evade our immune responses or change how sick they make us.
There are many different types — or species — of viruses. Some viruses have round shells; some have long shells. Different viruses use different hooks, or receptors, to hold onto and enter a cell. A specific virus usually only infects a certain species or related species. If your dog gets a cold, you’re usually not going to get it. Sometimes, though, a virus can infect different species
