Your Guide To Adult Vaccines
En español | The first vaccine to fight COVID-19 has been authorized for emergency use by the federal government — a move that could slow the spread of coronavirus and help bring an end to the pandemic — and another candidate is right behind it in the process. By the end of the year, millions of high-risk Americans will likely be vaccinated against a virus that has so far killed nearly 300,000 people in the U.S.
But the unprecedented speed of vaccine development has generated a number of misconceptions that have fueled skepticism among some Americans. Here are some prevalent coronavirus vaccine myths and the truth behind the medicines designed to combat COVID-19.
Myth #1: If you've had COVID-19 already, you don't need to get vaccinated.
The verdict is still out when it comes to how long you are protected from COVID-19 after a previous infection — what's referred to as natural immunity. In fact, “early evidence suggests natural immunity from COVID-19 may not last very long,” the Centers for Disease Control and Prevention (CDC) explains. Because of this, “people may be advised to get a COVID-19 vaccine even if they have been sick with COVID-19 before,” the agency states.
Health officials will keep the public informed with any developments and recommendations as more is learned about the duration of natural immunity.
Myth #2: Once you receive the coronavirus vaccine, you're immune for life.
It's also unknown how long immunity from a coronavirus vaccine will last and whether it will need to be administered more than once, or even on a regular basis, like the flu shot.
For now, “we should think about this as maybe in the same zone as a tetanus shot, where you might need a booster” every few years, National Institutes of Health (NIH) Director Francis Collins, M.D., said in a recent AARP tele-town hall on the subject. “If we're lucky, it would be like measles, where once you're immune, you're immune for life, but that would be really lucky,” he added.
Myth #3: You can ditch your mask after you get vaccinated.
The vaccine is one tool that can help slow the spread of the coronavirus, but others will be needed to bring the pandemic to an end — these include mask wearing, social distancing, frequent handwashing and testing.
One reason: It will likely take several months to get the majority of Americans who want a coronavirus vaccine vaccinated, health officials predict. And until a substantial portion of the population develops resistance to COVID-19 and so-called herd immunity is reached, the virus will continue to spread and sicken people.
Another: Protection isn't instantaneous. “It typically takes a few weeks” for the body to develop memory cells for the virus after vaccination, which means “it is possible that a person could be infected” with the coronavirus just after receiving the vaccine and then get sick with COVID-19 “because the vaccine did not have enough time to provide protection,” the CDC explains. In this case, face masks, social distancing and other recommended efforts can help prevent an infection while the body builds up immunity.
Finally: While the leading vaccines have proven effective at preventing COVID-19, it’s not yet clear whether they can block virus transmission. Masks, however, have demonstrated their effectiveness at stopping virus particles from infecting others.
“We have to do everything in our power to figure out how to stop this virus today and set ourselves up for the best success so that as the vaccine continues to be rolled out, we can really give it its best chance to additionally stop spread,” said Michael Mina, M.D., assistant professor of epidemiology at Harvard's T.H. Chan School of Public Health.
Myth #4: The vaccines use a live version of the coronavirus.
None of the vaccines in late-stage development in the U.S. use the live virus that causes COVID-19, the CDC confirms. Instead, the leading vaccine candidates use scientific techniques to train the human body to recognize and fight the coronavirus by either introducing a harmless piece of the virus (not the entire germ) to the body or by giving the body instructions to make its own coronavirus-like protein. The body then recognizes these proteins shouldn't be there and produces antibodies to fight them off. Then, the immune system establishes memory to protect against future infections.
While the coronavirus vaccines will not make you sick with COVID-19, like other vaccines, including the flu shot and the vaccine that protects against shingles, they can cause side effects in some people. A small share of participants enrolled in the Pfizer/BioNTech and Moderna/NIH clinical trials reported temporary side effects after their shots. Symptoms included injection site pain, fatigue, headaches, chills and muscle aches. Researchers have so far not identified any major safety concerns with these two vaccines, but participants and early vaccine recipients will be monitored for long-term adverse events.
Myth #5: mRNA vaccines can alter your DNA.
Two of the four vaccine candidates in late-stage U.S. trials (the Pfizer/BioNTech vaccine, which was authorized by the federal government on Dec. 11, and the Moderna/NIH vaccine) utilize a new type of technology called messenger RNA, or mRNA for short. Think of mRNA as an instruction manual: It directs the body to build an immune response to a specific infection.
Currently, there are no licensed mRNA vaccines in the U.S., and the newness of them has generated suspicion among some. One widely circulated myth on social media claims that mRNA vaccines can alter human DNA. This, however, is not the case, according to experts at the CDC.
For starters, the mRNA from the vaccine “never enter the nucleus of the cell, which is where our DNA are kept. This means the mRNA does not affect or interact with our DNA in any way,” the CDC states. What's more, after the cells use the instructions the mRNA delivers — in the case of the COVID-19 vaccines, the instructions are to build the coronavirus’ signature spike protein so the body can develop an immune response should it ever encounter the real deal down the road — they destroy the mRNA.
Though new, the CDC stresses that mRNA vaccines will be held to the same safety and effectiveness standards as other vaccines that are approved or authorized in the U.S.
Myth #6: You don't need both doses of the two-dose vaccines.
All but one of the vaccines in late-stage development require two doses that are given a few weeks apart. And because health experts are not sure whether one dose will be effective enough to prevent COVID-19 or a severe case of the illness, skipping the second shot is not a good idea. As the CDC explains: The first shot starts building protection; the second shot boosts that protection and “is needed to get the most protection the vaccine has to offer.”
A peer-reviewed analysis from Pfizer/BioNTech's phase 3 clinical trial found that its vaccine had an efficacy of about 52 percent after the first shot. After the second dose, the efficacy jumped to 95 percent. Efficacy data for the other two-dose vaccines is still pending.
"We don't know what happens after a single dose,” William Moss, M.D., executive director of the International Vaccine Access Center at the Johns Hopkins Bloomberg School of Public Health, told AARP in a previous interview. “Certainly, we can't expect [that one dose will confer] the high degree of protection” that both doses demonstrated in phase 3 clinical trials, he added.
Myth #7: If you got the flu shot this year, you don't need a coronavirus vaccine.
While the flu and COVID-19 share a similar list of symptoms, they are two different illnesses, caused by two different viruses. So when it comes to the vaccines, “it's not one or the other,” Anthony Fauci, M.D., director of the National Institutes of Allergy and Infectious Diseases (NIAID), explained in a recent AARP tele-town hall event.
"You want to be doubly protected from the flu and from coronavirus,” Fauci said — especially since it's possible to get infected by both viruses at the same time, or one right after another, which can be taxing on the lungs and other organs.