What just happened?
Within the past week, two pharmaceutical companies—Pfizer and Moderna—have submitted applications to the Federal Drug Administration (FDA) and other regulatory agencies around the world for use and distribution of their COVID-19 mRNA vaccines.
Pfizer says it can produce globally up to 50 million doses in 2020 and up to 1.3 billion doses by the end of 2021, and that it will be ready to distribute the vaccine within hours after authorization. By the end of 2020, Moderna also expects to have approximately 20 million doses of their vaccine available in the United States and are expected to manufacture 500 million to 1 billion doses globally in 2021.
How do vaccines work?
Vaccines reduce the risk of getting a disease by working with your body’s natural defenses to build protection. Essentially, vaccines work because God has designed our bodies to not only fight against invasive germs, but to remember them—and remember how to destroy them.
When you get a vaccine, your immune system responds by (1) recognizing the invading germ (virus, bacteria, and so on), (2) producing antibodies (i.e., proteins produced naturally by the immune system to fight disease), and (3) remembering the disease and how to fight it when exposed in the future.
A vaccine safely introduces the “invading germ” in one of three ways. The first approach is to “inactivate” the virus so that its major components still work but won’t cause infection. This is how polio, hepatitis A, and influenza (injected version) works. The second approach is to use a weakened strain of the virus that, while technically still alive, isn’t strong enough to cause harm. This is called an attenuated vaccine, and it’s how both the measles, one shingles vaccine (Shingrix®), and the human papillomavirus (HPV) work. The third approach is to use specific components of the virus’s genetic sequence, instead of the virus itself. This is how mRNA vaccines work.
How does an mRNA vaccine work specifically?
As stated above, most vaccines use inactivated or weakened versions or components of the disease-causing pathogen to stimulate the body’s immune response to create antibodies. Vaccines that use mRNA, though, take a different approach. As the Centers for Disease Control (CDC) explains, mRNA vaccines take advantage of the process that cells use to make proteins in order to trigger an immune response and build immunity to SARS-CoV-2, the virus that causes COVID-19.
With mRNA vaccines, so named for the strands of genetic material, mRNA is inside a special coating that protects it from enzymes in the body that would otherwise break it down (contrary to some misconceptions, mRNA vaccines do not enter the cell’s nucleus, so it cannot “change a person’s DNA” or genetic code).
The mRNA is essentially an instruction for the cell on how to make a harmless piece of the “spike protein” that is unique to SARS-CoV-2. Since only part of the protein is made, it does not harm to the person vaccinated. After the piece of the spike protein is made, the cell breaks down the mRNA strand and disposes it using enzymes in the cell. Once displayed on the cell surface, the protein causes the immune system to begin producing antibodies and activating T-cells to fight off what it thinks is an infection. These antibodies are specific to the SARS-CoV-2 virus, which means the immune system is primed to protect against future infection.
As with all vaccines, the benefit of mRNA vaccines is that those vaccinated gain this protection against a virus without ever having to risk the serious consequences of getting sick with COVID-19.
Will an mRNA vaccine make me sick or cause me to get COVID-19?
No, because the vaccine is not infectious (i.e., does not use an inactivated or weakened version of the virus) there is no chance it will cause you to get COVID-19.
Are the vaccines safe?
The COVID-19 vaccines were tested in large clinical trials to ensure they meet safety standards. Tens of thousands of people were recruited to participate in these trials to determine how the vaccines offer protection to people of different ages, races, ethnicities, and health.
A clinical trial includes three phases. According to the Federal Drug Administration (FDA), in Phase 1 the vaccine is given to a small number of generally healthy people to assess its safety at increasing doses and to gain early information about how well the vaccine works to induce an immune response in people. Phase 2 studies include more people, where various dosages are tested on hundreds of people with typically varying health statuses and from different demographic groups, in randomized-controlled studies. These studies provide additional safety information on common short-term side effects and risks, examine the relationship between the dose administered and the immune response, and may provide initial information regarding the effectiveness of the vaccine. In Phase 3, the vaccine is administered to thousands of people in randomized, controlled studies involving broad demographic groups (i.e., the population intended for use of the vaccine) and generates critical information on effectiveness and additional important safety data. This phase provides additional information about the immune response in people who receive the vaccine compared to those who receive a control, such as a placebo.
In evaluating an emergency-use authorization for the COVID vaccines, the FDA requires vaccine makers to include evaluation of the chemistry, manufacturing, and controls information for the vaccine. FDA also uses all available tools and information, including records reviews, site visits, and previous compliance history, to assess compliance with current good manufacturing practices. As the CDC says:
Both this disease and the vaccine are new. We don’t know how long protection lasts for those who get infected or those who are vaccinated. What we do know is that COVID-19 has caused very serious illness and death for a lot of people. If you get COVID-19, you also risk giving it to loved ones who may get very sick. Getting a COVID-19 vaccine is a safer choice.
What does it mean for a vaccine to be effective?
Vaccine efficacy and vaccine effectiveness is a measure of the proportionate reduction in cases among people who have been vaccinated against a particular disease. According to the CDC, vaccine efficacy/effectiveness is measured by calculating the risk of disease among vaccinated and unvaccinated persons and determining the percentage reduction in risk of disease among vaccinated persons relative to unvaccinated persons.
The effectiveness of a vaccine is the proportionate reduction in disease among the vaccinated group compared to those who have not received the vaccine. For example, the Moderna virus was tested in a clinical trial of 30,000 American adults. Two weeks after receiving the second dose of the vaccine, only 11 people who were vaccinated developed COVID-19 symptoms compared to 185 symptomatic cases in a placebo group. This indicates a vaccine efficacy of 94.1 percent, or a 94.1 percent reduction from the number of cases you would expect if they have not been vaccinated. (In comparison, flu vaccination reduces the risk of flu illness by between 40 percent and 60 percent among the overall population.)
Additionally, the vaccine currently has a 100 percent efficacy against severe disease. This means that no one who received two doses of the vaccine has developed a severe case of COVID-19. In comparison, after two weeks 30 people in the placebo group developed a severe case, resulting in one death.
How are the vaccines made?
There are three different vaccine production technologies approved by the FDA for creating vaccines: egg-based, cell-based, and mRNA based.
Flu vaccines are most commonly made using an egg-based manufacturing process. To make this vaccine a candidate vaccine is injected into a fertilized chicken egg and incubated for several days to allow the viruses to replicate. The fluid containing the virus is then harvested from the egg to create a dose of the vaccine. Because one egg is needed to produce one dose of a vaccine this process requires large numbers of chicken eggs to produce. In the United States alone, nearly 140 million eggs are needed every flu season.
The second method is cell-based production. This is similar to the egg-based method except that instead of the virus being incubated in chicken eggs it is cultured in cells of non-human mammals.
The third method, and the one used for the Pfizer and Moderna COVID vaccines, involves using recombinant technology. Instead of a biological process (e.g., growing the virus in an egg or cell) it uses a chemical process. Because of this approach, mRNA vaccines can be created much quicker than egg or cell-based vaccines. A primary drawback, though, is that these vaccines have to be kept extremely cold. The Pfizer vaccine will need to be stored at minus-94 degrees Fahrenheit and will degrade in around five days at normal refrigeration temperatures of slightly above freezing. Moderna says its vaccine can remain stable at standard refrigerated conditions, of 36 to 46 degrees Fahrenheit, and for up to 30 days after thawing.
Why do some of the COVID vaccines require one shot while others require two doses?
The CDC points out, “All but one of the COVID-19 vaccines currently in Phase 3 clinical trials in the United States need two shots to be effective. The other COVID-19 vaccine uses one shot.”
As noted above, when exposed to a germ, such as a virus or bacteria, the human immune system develops an immunological memory and “remembers” how to fight off the pathogen.
Some vaccines require a booster dose (or booster shot) that is given after the initial vaccination to increase or “boost” acquired immunity. A booster may be used because the body needs a “reminder” of the pathogen (which is why you need a tetanus shot every ten years) or to ensure that the body has built up enough immunity to fight off the infection.
The College of Physicians of Philadelphia notes recent research suggest the persistence of immunity against a particular disease “may depend on the speed with which that disease typically progresses through the body. If a disease progresses very rapidly, the immune system’s memory response (that is, the ‘watchdog antibodies’ generated after a previous infection or vaccination) may not be able to respond quickly enough to prevent infection—unless they’ve been ‘reminded about the disease fairly recently and are already watching for it.”
Are fetal cells being used in COVID-19 vaccines and treatments?
The short answer is “no.” A longer answer can be found in this article.
Why should Christians know about these vaccines?
There are two primary reasons Christians should be knowledgeable about these vaccines.
The first is that the process reveals the glory of God and should stir our gratitude. The creation of new vaccines often takes a decade, and the fastest-ever previously created took four years. But because of advances in technology and knowledge, it took less than a month to develop a COVID-19 vaccine (the rest of the time has been spent on clinical trials). It’s possible that an effective vaccine will begin distribution within the next few weeks.
This is an unprecedented blessing that would have been considered nothing less than miraculous for previous generations of Christians. While it’s understandable that some people (especially those unfamiliar with the underlying science) might be cautious, our first response to this news should be to express our thanks to a God who has made it possible to prevent the sickness and deaths of millions of people.
The second reason is that you need to be prepared for the coming debates that will affect your churches and communities. Just as states and localities have vaccination requirements for entry to daycares and public schools, we may soon see COVID vaccines required to engage in many areas of community life—perhaps even in churches. Discussions about such mandates should be rooted in neighbor love (Mark 12:31) and wisdom (Prov. 4:7). To do this well requires we seek out the most accurate information possible and base our judgment on God-given reason and prudence rather than on falsehoods and conspiracy theories.
By having a basic understanding of the process of vaccinations, we can be better prepared to lead our families, churches, and communities in ending this pandemic.
The Gospel Coalition