Get answers to common and evolving questions around a COVID-19 vaccine.
COVID-19 vaccine safety is a top priority. Any health issues related to a vaccination are taken seriously and researched thoroughly. Since COVID-19 vaccines became available, healthcare providers have been asked to report adverse events to the Vaccine Adverse Event Reporting System. The system is effectively working. Over 6.8 million doses of the Johnson & Johnson vaccine have been administered, and six reported cases of rare and severe blood clots were reported post vaccine. As a result, the Centers for Disease Prevention and Control (CDC) and Food and Drug Administration (FDA) advised a pause on administering the Johnson & Johnson COVID-19 vaccine. The Advisory Committee on Immunization Practices (ACIP), comprised of experts, will meet to further review the data and determine next steps.
Of the over 6.8 million vaccines administered, there have been six reported cases to date of vaccine-induced immune thrombotic thrombocytopenia (VITT). While this is an extremely rare side effect, it’s also severe and important to know what to watch for. Symptoms typically develop 5 to 13 days after being vaccinated and include an unusual or severe headache, severe abdominal pain or a painful, swollen leg, possibly accompanied by a skin rash of tiny reddish-purple spots.
If you experience any of these symptoms you should immediately contact your healthcare provider. Tell them when you received the Johnson & Johnson vaccine, what symptoms you are experiencing, and that are aware that people with suspected VITT should not be given the blood thinner heparin because it could worsen symptoms.
There are multiple variants of the novel coronavirus circulating globally. These variants seem to spread more easily and faster than other variants. So far, studies suggest that antibodies produced through vaccination with currently authorized vaccines recognize these variants. We do not know how these variants may affect existing therapies, vaccines and tests. There are studies underway to understand just that.
Before Getting Vaccinated
Although the CDC made recommendations on the initial priority groups for vaccination, it is ultimately up to your state for the vaccine rollout. State health departments are providing information on when and where vaccines are available. Find your state health department using our lookup tool. You can also search for availability through your local pharmacy by visiting vaccinefinder.org.
No. Like the flu shot and other vaccines, COVID-19 vaccines cannot give you the virus.
Yes. Due to the severe health risks associated with COVID-19 and the fact that reinfection with COVID-19 is possible, you should be vaccinated regardless of whether you already had COVID-19 infection. If you were treated for COVID-19 symptoms with monoclonal antibodies or convalescent plasma, you should wait 90 days before getting a COVID-19 vaccine. Talk to your doctor if you are unsure what treatments you received or if you have more questions about getting a COVID-19 vaccine.
Experts do not yet know how long someone is protected from getting sick again after recovering from COVID-19. The immunity someone gains from having an infection, called “natural immunity,” varies from person to person. It is rare for someone who has had COVID-19 to get infected again. It also is uncommon for people who do get COVID-19 again to get it within 90 days of when they recovered from their first infection. We won’t know how long immunity produced by vaccination lasts until we have more data on how well the vaccines work.
We also do not know if natural immunity protects someone from the new circulating variants.
Having seasonal or food allergies does not mean you will experience a reaction to the vaccine. If you have a history of severe allergic reactions you should talk to your physician before receiving an mRNA COVID-19 vaccination. They will help you determine if you have experienced a severe allergic reaction (e.g., anaphylaxis) to any component of a COVID-19 vaccine listed in the prescribing information, in which case the vaccine would not be recommended. Established COVID-19 vaccination protocols suggest all persons be observed after vaccination for a minimum of 15 minutes.
No, vaccines were granted emergency use authorization because they are deemed safe and effective. The U.S. Food and Drug Administration’s (FDA’s) Center for Biologics Evaluation and Research is responsible for regulating vaccines in the United States. And each vaccine producer must follow a multi-step approval process that includes sharing research from clinical trials.
FDA can also require a manufacturer to submit the results of their own tests for potency, safety, and purity for each vaccine lot. Vaccines typically require years of research and testing before reaching the public, but scientists banded together across the globe to produce a safe and effective coronavirus vaccine more quickly. This doesn’t mean that the vaccine is less safe, it just means that the whole world is keen to ensure that we are protected from this new threat to lung health and so researchers have been working collaboratively to build a knowledge base of what works and achieved success quickly.
After approving a vaccine, FDA continues to oversee its production to ensure continuing safety. Monitoring of the vaccine and of production activities, including periodic facility inspections, must continue as long as the manufacturer holds a license for the vaccine product.
V-safe is a smartphone-based tool that uses text messaging and web surveys to provide personalized health check-ins after you receive a COVID-19 vaccination. Through v-safe, you can quickly tell CDC if you have any side effects after getting the COVID-19 vaccine. Depending on your answers, someone from CDC may call to check on you. And v-safe will remind you to get your second COVID-19 vaccine dose if you need one.
In addition, the Vaccine Adverse Event Reporting System (VAERS) is a national vaccine safety surveillance program that collects and analyzes side effects that occur. Reports from patients, providers, pharmacists and vaccine manufacturers can all be submitted to VAERS.
The government’s public-private partnership, Operation Warp Speed, has a goal to produce and deliver 300 million doses of safe and effective vaccines with the initial doses available by January 2021, as part of a broader strategy to accelerate the development, manufacturing, and distribution of COVID-19 vaccines, therapeutics and diagnostics.
Choosing a Vaccine
Health experts agree that the best vaccine is the one that is available to you. There are three types of vaccines that work in different ways:
- Messenger RNA (mRNA) vaccines contain a copy of genetic information that looks like the SARS-CoV2 (the virus that causes COVID-19) virus’s information that causes COVID-19. This gives our cells instructions for how to make a harmless protein that is unique to the virus. After our cells make copies of the protein, our bodies recognize that the protein should not be there and build T-lymphocytes and B-lymphocytes and antibodies that will remember how to fight the virus that causes COVID-19 if we encounter the virus in the future. The Moderna and Pfizer vaccines are mRNA vaccines.
- Viral vector vaccines contain a modified, weakened virus (not the COVID-19 virus) that delivers a message for a protein like the spike protein of the SARS-CoV2 virus to be made by our cells. By instructing cells to make large amounts of antigen, which then triggers an immune response, the vaccine mimics what happens during natural infection with SARS-CoV2 and stimulates an immune response that will protect you from future encounters from the COVID-19 virus. The AstraZeneca and Johnson & Johnson vaccines are examples of these.
- Protein-based vaccines contain harmless coronavirus proteins, not the whole virus, and produces an immune response against the virus. The Novavax vaccine is an example of protein-based vaccines.
The Lung Association, along with other public health experts, recommend getting any of the vaccines available to you as all have been shown to protect against COVID-19.
Comparing the efficacy of the three vaccines is a bit like comparing apples and oranges because the Johnson & Johnson/Janssen vaccine set out to answer a different question (does it protect against moderate to severe illness?) than the Pfizer-BioNTech and Moderna vaccines (do they prevent symptomatic infection?). Therefore, the different efficacy percentages can lead to confusion if you try to compare them looking only at the numbers.
In clinical trials both the Pfizer and Moderna vaccines have shown approximately 95% efficacy, which is very promising. This means that in the clinical trials, the vaccine prevented 95% of the clinical cases compared to the placebo group recipients. The Johnson & Johnson/Janssen vaccine is also very promising and has been shown to be 66% protective against moderate to severe illness, and 85% effective against severe illness. However, it’s important to note that we don’t know what will happen in the “real world” until researchers can evaluate those who have been vaccinated down the line.
Different types of vaccines require different types of administrations. For some types of COVID-19 vaccines, the first shot would prime the immune system, helping it recognize the virus and the second shot would strengthen the immune response. Both the Pfizer and Moderna vaccines require two doses: 21 days apart for the Pfizer vaccine and 28 days apart for the Moderna vaccine. The Johnson & Johnson vaccine is one dose. There isn’t information available on the need for booster shots—that would fall into long-term efficacy data which, we don’t have yet.
A second dose of mRNA COVID-19 vaccine should not be received earlier than the recommended schedule.
The second dose of COVID-19 vaccine should be administered as close to the recommended interval as possible. If this is not an option, the second dose can be given up to six weeks (42 days) after the first dose is given. There is limited efficacy data beyond this window but, it is recommended that if you go beyond this window, the vaccination series does not need to restart.
The mRNA COVID-19 vaccines are not interchangeable with each other or with other COVID-19 vaccine products.
After Getting Vaccinated
We only have preliminary data so far, based on phase 1 and 2 clinical trials, so it’s too early to fully report on side effects. In trials for the top vaccine candidates, Pfizer and Moderna, participants have said they experienced symptoms including fever, muscle aches, bad headaches and fatigue after receiving the shots, but the side effects generally did not last more than a day. Still, preliminary data suggests that, compared with most flu vaccines, the coronavirus shots have a somewhat higher rate of such reactions, which are almost always normal signs that the body’s immune response is kicking in.
The independent board that conducted the interim analysis of Moderna’s large trial found that severe side effects included fatigue in 9.7% of participants, muscle pain in 8.9%, joint pain in 5.2% and headache in 4.5%. For the Pfizer vaccine, the numbers were lower: Severe side effects included fatigue (3.8%) and headache (2%).
A key reason to get vaccinated is to protect against having severe complications up to and including death, especially among those who are in the high-risk group.
So, although it is important to be aware of safety and side effect issues around the vaccine, each person should weigh these usually mild side effects of arm soreness and fatigue for a day or two against the great benefit of protecting against moderate to severe illness which can occur at any age and in people without any underlying conditions.
If you have pain or discomfort following your COVID-19 vaccine, speak with your healthcare provider about taking an over-the-counter medication like ibuprofen or acetaminophen. It is important to take pain reliever after the vaccination, not before.
If you are experiencing pain where you got your shot you could try applying a clean, cool, wet washcloth to the injection area and be sure to use or exercise your arm. If you are experiencing discomfort from a fever, drink plenty of fluids, dress lightly.
Remember that side effects may be more intense after your second shot and are normal signs that your body is building protection and should go away within a few days. You should contact your healthcare provider if the redness or tenderness where you got your shot gets worse after 24 hours or if your side effects are worrying you and not gone after a few days.
Millions of people in the United States have received COVID-19 vaccines and they are safe and effective at protecting against COVID-19. Some people experience no side effects after vaccination while many will experience mild side effects, such as pain, swelling at the injection site, a headache, chills or a fever. A small number of individuals will experience a severe allergic reaction to an ingredient in the vaccine, but that is extremely rare and the reason for observation immediately after being vaccinated. Any time you experience symptoms that worry you it is time to discuss them with your healthcare provider.
You can help monitor for side effects using V-safe, a smartphone-based health checker if you have received a COVID-19 vaccine in the past six weeks. Using text messages and web surveys, it allows individuals who track any side effects and will follow up via phone with anyone who reports a medically significant adverse event.
It depends. Immunity is when the body can resist a particular disease, and vaccines help build up that immunity by stimulating antibody production and immune cells (T and B lymphoctyes) for future protection. Immunity works best at the community level so when enough people are vaccinated then an infected individual has nobody to spread the disease to. A vaccination can help prevent getting the infection or at least keeping the severity of the infection to a mild level. Everyone’s immune system responds a little differently.
That is possible, but uncommon. What you are referring to is also called breakthrough cases, and there have been instances of fully vaccinated individuals who became ill with COVID-19. No vaccine is 100% effective. In clinical trials, the available vaccines showed an efficacy of between 72% - 95% in protecting against moderate-to-severe illness. That high level of immunity against SARS-CoV-2, which we had no immunity whatsoever from pre-pandemic, is a huge advantage to protecting your health. However, until more people are vaccinated, and COVID-19 is no longer widely circulating, we’ll continue to see a small number of individuals become ill after being vaccinated. Health experts are researching these individuals to determine if any further guidance is warranted. Learn more at Lung.org/vaccines.
This is currently unknown. When we know how long immunity from the vaccine will last, decisions can be made about timing of re-vaccination.
Yes! Even when a vaccine is widely available, additional measures like masks and social distancing will still be necessary until the public health threat has subsided. It is an important safety measure not only for yourself but for those around you.
In the meantime, CDC came out with new guidelines for when you have been fully vaccinated. Once you are two weeks out from your final dose, you can once again gather indoors with fully vaccinated people without wearing a mask. You could also gather indoors with unvaccinated people from one other household without masks as long as they are not at increased risk for severe illness from COVID-19.
The American Lung Association urges members of the public to always consult with their own healthcare providers about whether this or any vaccine is appropriate for them.
Page last updated: April 19, 2021