Over the last month, the FDA approved not one, but two, COVID-19 vaccines. Both vaccines rely on an immunity-building strategy that hasn’t been used in any other vaccine. As many of us start rolling up our sleeves to get a shot, here are answers to some of the most frequently asked questions.
What is mRNA? Why does it matter?
All previous vaccines have been based on weakened virus molecules or proteins from the disease (pathogen) that our immune systems can easily overcome while learning to recognize it. The new vaccines from Moderna and Pfizer — the two that have made it to market so far in the U.S. — contain mRNA (messenger RNA), which is a genetic template that instructs our cells to build the viral proteins that our immune systems can then recognize. Its main perk is that by allowing our bodies to produce the proteins (rather than growing them in a lab like in traditional vaccines), it slashes the time it takes to produce the vaccine (as done in the past) in the lab. For nearly 20 years, researchers have been interested in using mRNA in vaccines. Some were even tested in early clinical trials for rabies, influenza and Zika. However, the vaccines for COVID-19 are the first mRNA vaccines ever approved by the FDA. This long history of studying the mRNA concept is why the vaccine could be developed so quickly. mRNA is new to you and me, but a well-known process to scientists.
Will the COVID-19 vaccine change my DNA?
mRNA is a messenger in your body. It’s the way your DNA tells the rest of your body what proteins to create for various functions. In your body, mRNA is created in the nucleus of your cells, based on the DNA that resides there. Then the mRNA exits the nucleus to be used as a template for protein-making in the rest of the cell, and it has no way back in. Soon, it degrades without ever re-entering the nucleus or coming in contact with DNA. mRNA lives in the body between a few hours and a couple of days.
Like naturally occurring mRNA that has already left the nucleus of your cells, the mRNA vaccine isn’t able to enter your cell’s nucleus. Because of that process, it can’t come in contact with or change your DNA. Click here to see a video that explains the process more fully.
Why do I need two shots?
Multiple doses of the vaccine expose our immune systems to more of the viral proteins, giving it the chance to develop more antibodies and protection. The immunity takes time to develop. Researchers believe that 10 days after the first dose, patients develop about immunity that is 52% effective. About a month after receiving their second dose, immunity can reach 94%. A similar strategy is used for other vaccines, like Shingrix, developed to prevent shingles.
How does the FDA decide if a side effect is severe?
The FDA has a toxicity grading scale to rate adverse events related to preventive vaccines. It ranks both local events (like injection site pain) and systemic events (like fever and nausea) as mild (Grade 1), moderate (Grade 2), severe (Grade 3) or life- threatening (Grade 4.) Several effects, like pain at the injection site, headache, fatigue and nausea, are considered Grade 1 if they do not interfere with your activity at all. If side effects do prevent you from doing ordinary tasks, they may be designated Grades 2 or 3. If the symptoms cause you to go to the emergency room for treatment, they are Grade 4.
Is the COVID-19 vaccine safe?
The most common side effects for both vaccines — headache, fatigue, fever, chills and muscle and joint pain — are more intense than those for the flu, for example. And the side effects caused by the COVID-19 vaccine tend to be worse after the second shot than the first.
The FDA reported that up to 4.6% of Pfizer vaccine patients and 9.6% of Moderna’s patients experienced severe (Grade 3) adverse effects. Grade 3 effects are those serious enough to interrupt a person’s life — for example, by causing them to take a day off of work — but not so severe that the person is hospitalized. Younger patients were more likely than older ones to experience severe adverse effects. No life-threatening effects were linked to the Pfizer vaccine and less than 0.1% of patients experience Grade 4 adverse effects to Moderna’s vaccine.
A few people have developed Bell’s palsy, a sudden (and usually temporary) paralysis of the face, after each vaccine. So far, six people have had serious allergic reactions to Pfizer’s vaccine.
Covid-19 vaccines have not been tested on pregnant or lactating women or on children. It also will need to be tested on millions of more people for scientists to understand how the vaccine may interact with certain chronic illnesses or other drugs.
Check out MedShadow’s vaccine side-effects tracker for more details.
How long were test patients followed and why?
The FDA required that patients in the Phase 3 trials be followed for a median of two months after the second shot before the data would be reviewed for its approval.
When it comes to side effects, the CDC considers vaccinations different from other medicines, because they aren’t taken continuously. In general, the CDC designates adverse events that happen within six weeks of administration to be potentially linked to vaccines. In the case of the Pfizer and Moderna vaccines, the mRNA is broken down within days of the injection, so it doesn’t remain in your body long term.
The CDC is tracking possible adverse reactions in early recipients through its V-safe app. The agency initially announced that it would follow these patients for six weeks, but has since said it will check in on them at three months, six months and one year after receiving the vaccine. See why MedShadow is insisting that the group extend the collection to all vaccine recipients indefinitely.
Who has been tested for the vaccine?
Both vaccines have been approved for adults. While Moderna’s has the okay for patients 18 and older, Pfizer’s trial included a small number (163) of 16- and 17-year-olds and has been recommended for patients 16 and older. Both vaccines are now being tested in patients as young as 12 to 15.
The vaccines were effective in both men and women, regardless of weight or race. While Pfizer’s vaccine appears to be just as effective in older patients (65 and older) as in younger ones, Moderna’s vaccine offered slightly less protection (86% compared to 96%) in older patients versus younger ones.
Neither trial included pregnant or lactating women. While immuno-compromised people (such as those with the HIV, human immunodeficiency virus) were included in the trials, there isn’t enough information yet to determine if the vaccines offer different levels of protection to these groups.
When will it be available to me?
Healthcare workers and people in long-term-care facilities are getting the COVID-19 vaccine now. Next up will be people who are over 75 and frontline essential workers (like teachers and grocery-store clerks). They can hope to be vaccinated in January. States will individually determine who comes next based on their risk of exposure through their jobs or an underlying health condition. The remainder of adults will likely be able to get the vaccine in April, May or June. Those under the age of 16 will have to wait longer.
Will the COVID-19 vaccine protect me from mutated versions of the virus?
Researchers have identified several mutated forms of the virus spreading in the UK and South Africa. Each strain has several mutations, and some of those are in the protein that the vaccines target. Scientists believe the vaccines will still protect against these strains, but are running studies to confirm it. The short answer is: “Probably, but we can’t be sure just yet.”
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