Vaccines 101
Vaccines are some of the most important medical interventions that exist today because they can actually prevent us from getting sick with – and spreading – dangerous diseases.
Some of the most severe and devastating infections we have dealt with throughout history are much less common today because of vaccines. Polio caused paralysis in children all over the world until a vaccine was introduced. Today, there are no cases in the United States and only rare cases in a limited number of countries where access to vaccines is more limited.
Similarly, smallpox led to widespread illness and death for centuries, until a vaccine – and a worldwide effort to get vaccinated – led to its complete elimination. There hasn’t been a single reported case of smallpox since 1977.
What is a vaccine and how does it work?
A vaccine is designed to train the body’s immune system to recognize a specific infection so that it can be defeated quickly.
Each vaccine is designed to help prevent a specific germ. When we receive a vaccine, our immune system is trained to recognize a potential infection, which triggers special cells to seek out and fight the perceived source of danger. These cells then send out signals, letting the rest of the immune system know that a germ is present. Other cells then produce “antibodies” or, immune proteins designed to target the germ and protect our body from future infections.
These antibodies will stand ready in the body for any signs of that germ and attack it as soon as it is detected. Some antibodies offer protection from the virus for a few months, while others may protect for a lifetime. Depending on how long those antibodies last (and the type of vaccine you receive) you may only need one dose of a vaccine or you may require “boosters” to keep your immune system ready.
Most COVID-19 vaccines currently under development will require two doses to be fully effective, meaning immunity will not be reached until approximately 10-14 days after they have received their second dose. Regardless of where an individual is in the vaccination process, it is critical that we all maintain good PPE and social distancing practices for the duration of the pandemic, as the vaccines are not known to prevent transmission and even those with immunity could still carry and transmit the virus to those who are not.
Do vaccines cause side effects?
Clinical trials are closely monitored for any signs of side effects to ensure that the trial remains safe for participants and eventually, others who may receive the vaccine. This is the responsibility of a group called the Data and Safety Monitoring Board (DSMB), consisting of an independent group of expert scientists. Due to the high-profile nature of the COVID-19 clinical trials, members of the DSMB have been kept anonymous to protect against any external pressure.
Researchers follow participants during the study for any signs of side effects. All symptoms are tracked closely and reported in the results of the trial when it is completed.
Some are mild – such as feeling tired or having a low-grade fever. More serious side effects are reported to the U.S. Food & Drug Administration (FDA) and the DSMB for further review. In some cases, concerning side effects have led to studies being put on hold until further investigation. The purpose of these trials is in large part to identify the exact dose that will ensure the greatest protective effect while minimizing side effects.
All vaccines have some risk of side effects, though most of them are mild and short in duration. In early studies of the COVID-19 vaccines, common side effects included discomfort at the injection site, muscle aches, and feeling slightly feverish after vaccination. Full details regarding side effects related to each vaccine will be published with the FDA’s emergency use authorization (EUA).
For the COVID-19 vaccines currently under development, the FDA is requiring participants to be monitored for at least two months after they receive the vaccine to ensure there are no significant safety concerns before approving the vaccine for the EUA.
Why is it important to be vaccinated?
Vaccines have saved the lives of many people around the world by protecting them and preventing them from becoming infected with different germs. Diseases that used to be very common such as measles, meningitis, and whooping cough are now very rare because of vaccines. In addition to protecting yourself, receiving a vaccine helps to protect your friends, family, and your entire community.
When you are protected from infection with a germ, you are also protected from spreading that germ to others. If enough people in a community are immune to a germ, the germ is unable to spread through the community and cause an outbreak. This is called “herd immunity” and is especially important to protect the most vulnerable members of our communities that are unable to receive a vaccine themselves – such as newborn babies and people with a weakened immune system. During a pandemic, such as COVID-19, if a large number of people are immune to the germ as a result of vaccination or infection, it can help stop the spread and end the pandemic.