Healthcare professional holding a vaccine.

The Science of Vaccines & COVID Vaccine Effectiveness

As of March 29, 2021, roughly one in five adults in the United States have been fully vaccinated for the novel coronavirus. More than 180 million vaccines have been distributed countrywide, more than 95 million Americans have received their first vaccine against COVID-19, and 52 million people have been fully inoculated, representing 15.8% of the U.S. total population. 

To date, three different vaccines for COVID-19 have been authorized for emergency use in the United States by the U.S. Food and Drug Administration (FDA). 

According to the CDC, “All COVID-19 vaccines currently available in the United States have been shown to be safe and effective at preventing COVID-19.

Nevertheless, there are some looming questions in regards to the coronavirus vaccine’s efficacy as new cases emerge. Many people are wondering:

  • Is the COVID vaccine safe?
  • How effective is the COVID vaccine?
  • For how long is the COVID vaccine effective? 

In this post, we will discuss what we currently know about vaccine effectiveness for COVID-19 vaccines.

How Do COVID Vaccines Work?

Before talking about the COVID vaccine efficacy, it’s important to understand how vaccines work and how our bodies protect us against disease.

Think of the immune system as cells and tissues dedicated to defending our body from small, disease-causing organisms  such as bacteria, viruses, parasites, and fungi. These disease-causing microorganisms are called pathogens.

According to the CDC, when an “outsider”, such as the virus SARS-CoV-2, invades our bodies, it multiplies. This invasion, called an infection, is what leads to an illness such as COVID-19. Once the body identifies a threat, the immune system responds by releasing specific cells to fight and destroy/neutralize the virus. Our blood is made up of red blood cells, which transport oxygen to organs and tissues, as well as white blood cells, cells of the immune system, which help us fight infections.

The first time a person gets infected with SARS-CoV-2, the virus that causes COVID-19, it can take a few days or even weeks for their body to use all of its invader-fighting tools to fight against the infection. But afterward, the person’s immune system (thanks to the memory B & T cells) remembers the virus and knows how to better protect the body against it in the future. Experts are still learning how long our immunological memory lasts to help us fight against future novel coronavirus infection. 

The COVID-19 vaccines help our bodies to stimulate the immune system to induce immunological memory without causing disease. Although different types of vaccines have differing mechanisms to provide protection against infections, with all of them, the general idea is that the body is left with “memory cells” to remember how to fight against a given virus in the future. Generally, it takes a few weeks after receiving the vaccine for our bodies to produce B & T cells. Therefore, people who have been vaccinated against COVID-19 could still be infected with or spread the virus within the weeks right after receiving the shot.

According to Helen Chu, an infectious-disease expert at the University of Washington School of Medicine in Seattle who directs the Seattle Flu Study, mRNA COVID-19 vaccines, the vaccines made by Pfizer and Moderna, produce a strong immune response in our bodies which could increase the risk of well-known side effects, indicating that the vaccines are working and our immune systems are responding. 

Some Americans have expressed uncertainty about whether or not to get the COVID-19 vaccine. Dr. Chu, who received the Pfizer-BioNTech vaccine shared that 6 hours after the second dose she experienced chills, a high fever, muscle aches and slept for 24 hours. “Then, by 36 hours later, it was totally over and I was back to normal”, she described. Dr. Chu, similar to many people who have decided to get the COVID-19 vaccine, said she would rather experience the vaccine’s possible side effects than cope with COVID-19—“a potentially mortal disease that could kill me”—she said. 

The bottom line is that the U.S. FDA-EUA authorized vaccines reduce the transmission of the virus that causes COVID-19 and are one of the many tools to reduce the number of COVID cases. It’s crucial to continue implementing the well-known safety strategies that bring us much closer to life beyond the pandemic.

Find a COVID-19 testing or vaccination location near you.

Curative Inc. and its subsidiary, Curative Management Services LLC, engage with medical entities that provide vaccination services.

Related Posts

Sign Up For Our Newsletter

Get the latest insights on the global effort to end COVID-19, as well as Curative's newest, innovative health services.