COVID-19 Vaccination Information and Resources
As of now in the United States, there is no authorized or approved vaccine to prevent COVID-19. But work is underway both to develop safe and effective vaccines and to make plans for distributing them.
As this work goes on, the Mount Sinai Health System will keep this page updated with the most current information on the availability, use, effectiveness, and timing of these vaccines.
Frequently Asked Questions About COVID-19 Vaccines
Because information about the development of COVID-19 vaccines changes often, we are regularly updating answers to the most frequently asked questions.
The goal is to have a safe and effective vaccine available in 2021. But a number of things have to happen first.
In the United States, vaccines must be approved by the Food and Drug Administration (FDA) before they can be used. The FDA bases its decision on data from clinical trials. This data is reviewed by scientists and physicians who are experts in vaccine safety and effectiveness. They are not a part of the government and they are not politically appointed. They do not work for pharmaceutical companies. Some are independent experts; others are career scientists and physicians at the FDA.
In a clinical trial, tens of thousands of people are sorted into two groups. One group receives the vaccine. The other group receives a placebo, meaning an injection that doesn’t contain any vaccine. Scientists observe whether the people who got the vaccine get fewer cases of the disease than those who got the placebo. This means that the vaccine appears to work in those people; this is called the vaccine’s “efficacy.” The scientists also watch out for unexpected side effects that the vaccine might have caused. This is called the vaccine’s “safety.”
If the clinical trial data shows enough evidence of efficacy and safety, the FDA will approve the vaccine and license it for use in the United States.
Sometimes, the FDA will allow a medical product that has not yet been fully approved to be used in an emergency to diagnose, treat, or prevent a serious illness. This is called “emergency use authorization” or “EUA”.
An EUA may be issued when the FDA determines that the product “may be effective” against the disease based on all the available scientific evidence. This is a lower standard than required for full approval of a product; it uses early data gathered from clinical trials.
More information on EUAs is available from the FDA website.
Not immediately. After a vaccine receives approval or Emergency Use Authorization, it must also be reviewed by the Governor’s Clinical Advisory Task Force. This group will give an independent opinion on the safety and efficacy of the vaccine before it can be distributed in New York State. The Task Force has seven members, including highly respected scientists like Adolfo García-Sastre, PhD, Irene and Dr. Arthur M. Fishberg Professor of Medicine at the Icahn School of Medicine at Mount Sinai. We do not yet know how long that additional review might take.
We also don’t know yet how long it will take to manufacture a vaccine and distribute it to hospitals and doctor’s offices.
If a COVID-19 vaccine receives an emergency use authorization, there won’t be enough of it at first for everyone who wants to be vaccinated to get it. Public health authorities, including the New York State Department of Health (NYS DOH) and the New York City Department of Health and Mental Hygiene (NYC DOHMH), will recommend who will be offered the vaccine first once it is made available. Their initial plans were released in October. In general, front-line health care workers, especially those workers who may be at risk of exposure to patients who are critically ill with COVID-19, will be offered the vaccine first. Residents of long-term care facilities (like nursing homes) and employees who regularly interact with them would also be included in the first phase.
As more vaccine is distributed, it will be offered to additional groups of people, including other essential workers and those who have high-risk medical conditions. As more vaccines become available, they will be offered to more people.
The FDA reviews all vaccines for safety before allowing them onto the market. In New York State, the Governor’s Clinical Advisory Task Force will also offer an independent opinion about each vaccine’s safety and efficacy.
No. None of the vaccines in advanced clinical trials can give you COVID-19.
No. The Advisory Committee for Immunization Practices (ACIP), a group of medical and public health experts that advises the Centers for Disease Control and Prevention (CDC), also assesses the safety and efficacy of vaccines. They will also develop recommendations on COVID-19 vaccine use. Additionally, in New York State, the Governor’s Clinical Advisory Task Force will independently review the vaccines as they are made available.
According to the Governor’s plan, “The Task Force’s independent review of any federally authorized COVID-19 vaccine will help address publicly reported concerns about the scientific process and rush to market. The Task Force will rely on numerous data sources including public information and the findings of expert third party independent organizations.”
There is a lot of information on the internet about vaccines, and it can be difficult to know which sites to trust. Mount Sinai is providing a tool called NewsGuard, which is a browser extension you can download that will help determine which information about vaccines and other health topics is accurate.
If you have had COVID-19 and recovered, it is still worthwhile to get a COVID-19 vaccine. While most people are protected from getting COVID-19 again after they’ve recovered, we don’t know how long that protection lasts.
If you get a vaccine, you should still protect yourself by wearing a mask and social distancing. We don't know how effective the vaccine is going to be. It’s possible, for example, that the vaccine will protect you from getting very sick with the virus, but it will not prevent you from spreading the virus to other people. Until we have a better idea of that and know how many people are going to receive it, you should still practice social distancing, wear a face mask, and wash your hands often and well. We're going to have to do all of this for a little while longer until we know more and until the pandemic is more under control.
Herd immunity means that enough people in a community are immune to a disease that the disease can’t spread easily among them. That helps protect people who are not immune—for example, those who can’t be vaccinated for some reason—from getting sick. In the case of COVID-19, we don’t yet know how many people need to be vaccinated to reach herd immunity. But we are likely still far away from that point.
The preliminary data from the first two vaccines—from Pfizer and Moderna—is that their vaccines have an efficacy of 94 to 95 percent. That means that under the controlled conditions of the trial there were 94 to 95 percent fewer cases of COVID-19 in the group of people who got the vaccine compared to the group of people who got the placebo.
The third vaccine, from AstraZeneca, had an efficacy of between 62 percent and 90 percent, depending on how the doses were given.
These are all very high efficacy numbers, meaning the vaccines worked well in these trials. Under real-world conditions, the effectiveness of the vaccines may turn out to be different. But this data is very promising.
Pfizer, Moderna, and AstraZeneca have all released data that suggest their vaccines are safe. We’re still waiting on complete data from the phase 3 clinical trials to know more. Once we have this additional information, we’ll also know more about side effects. None of the three companies has released information about mild or moderate side effects just yet. We do, however, have some information about severe side effects of the Pfizer and Moderna vaccines.
Pfizer reported on side effects that were considered severe or interfering with daily activity. These were fatigue, in 3.8 percent of participants, and headache, in 2 percent. Most of these side effects went away shortly after vaccination. Older adults tended to report fewer and milder side effects.
Moderna reported that the majority of their vaccine’s side effects were mild or moderate in severity. Like Pfizer, however, Moderna has only shared more specific numbers around side effects that were considered severe or interfered with daily activity. These side effects were only included if they occurred in more than 2 percent of patients. Only one side effect after the first dose has been reported, which was pain at the injection site (2.7 percent). After the second dose, reported side effects included fatigue (9.7 percent), muscle pain (8.9 percent), joint pain (5.2 percent), headache (4.5 percent), pain at the injection site (4.1 percent), and redness at the injection site (2 percent). Most of these side effects lasted only a short time after the injection.
AstraZeneca said that no serious safety concerns were reported for its vaccine but it has not released information on side effects yet.
We will continue to update you as these companies release more information about both safety and side effects.
Vaccines expose us to pieces of either a bacteria or a virus. Our body mounts an immune response by making antibodies against those pieces. Antibodies are proteins that fight germs like viruses and bacteria by latching onto and disabling them. The goal is that our body will then recognize those pieces and use the antibodies to fight off any future exposure to the real bacteria or virus.
There are several different types of vaccines.
Traditional vaccines include pieces of the virus in them. This causes your immune system to react by making antibodies against those pieces.
The AstraZeneca vaccine uses a common cold virus that is combined with just one piece of the COVID-19 virus, called the “spike protein.” The spike protein is an important and recognizable part of the virus. When the immune system makes antibodies against the spike protein, they can disable the entire virus.
The Pfizer and Moderna vaccines are called “messenger RNA” vaccines. They do not contain pieces or proteins from the virus. Instead, they contain instructions for your cells, called “messenger RNA.” This messenger RNA tells your cells to make the COVID-19 spike protein themselves. Once your cells make the spike protein, your immune system will make the antibodies that fight COVID-19 and protect you from getting sick from this virus.
Some of the vaccines that are being tested—including the Pfizer, Moderna, and AstraZeneca vaccines—require two doses three to four weeks apart. It is very important that you get both doses at the recommended times.
We do not yet know how long the protection from these vaccines will work. It is possible that you will need to get additional shots in the future.
There are a lot of myths on the internet about COVID-19 vaccines. Mount Sinai is working with a company called NewsGuard to provide the most accurate information. If you’ve heard something that sounds questionable and want to know if it’s true or not, you can look it up in NewsGuard’s report on the top COVID-19 vaccine myths.