FAQs Regarding COVID-19 Vaccination

Updated: May 6, 2021

Below is a list of frequently asked questions about the SARS-CoV-2 vaccine that have come up during Columbia town hall forums. These FAQs will be updated as new vaccines and information become available.

Please be aware that you should discuss the vaccine and any questions you have about it with your healthcare provider. The vaccines are currently being distributed to various states. In New York City, prioritization of the vaccine will follow New York State and CDC guidance. 

* On April 23, 2021, the FDA and CDC lifted the recommended pause on the Johnson & Johnson (Janssen) COVID-19 vaccine use following a thorough safety review. Read more.

Questions About the Vaccines (types, how they work, efficacy, safety, etc.)

There are currently three vaccines that have received Emergency Use Authorization by the U.S. Federal Drug Administration. These include the Pfizer BioNTech vaccine, the Moderna vaccine, and the Johnson & Johnson's Janssen vaccine.* 

The Pfizer and Moderna vaccines use genetic material known as messenger RNA (often abbreviated as mRNA) that cells use to make proteins. When the vaccines are injected into the body, the mRNA which codes for the coronavirus spike protein, enters human cells and instructs the cells produce a protein that mimics the spike proteins found on the surface of the coronavirus. These vaccine-induced proteins then stimulate the immune system to produce antibodies to fight the virus. Once produced, if a person is exposed to SARS-CoV-2, the antibodies latch onto the coronavirus spike protein and prevent the invading virus from entering your cells and making you sick.

The Johnson & Johnson vaccine uses a different approach to deliver the gene encoding the coronavirus spike protein. This is the viral vector approach. In this instance, a harmless cold virus, adenovirus type 26, is modified in the laboratory in two essential ways: (1) some of the Ad26 DNA is removed which renders the Ad26 non-replicative (i.e., it cannot grow or multiply in your body); and (2) DNA coding for the coronavirus spike protein is inserted into the Ad26 vector.  Once injected, the spike protein is produced and an immune response to it is generated. The resultant antibodies to the spike protein act in a similar fashion to those produced in response to mRNA vaccines and prevent the entry of the invading virus into your cells.

Pfizer and Moderna require two doses, given three (Pfizer) to four (Moderna) weeks apart. Johnson & Johnson requires one dose.

No. None of the COVID-19 vaccines contain live SARS-CoV-2 virus.

All current COVID-19 vaccines in use in the US have been shown to be effective based on criteria from the US Food and Drug Administration (FDA). Findings from the Pfizer and Moderna vaccine studies showed that these vaccines were more than 90% effective in preventing symptomatic COVID-19. Findings from the Johnson and Johnson vaccine study showed that the vaccine was 72% effective in United States. It should be noted that comparison of efficacy across these vaccines can be misleading as the studies were conducted at different timepoints and in differing epidemic contexts. Real world data show that these vaccines are even more effective at preventing serious COVID-19 illness and hospitalizations.  

All three vaccines have been shown to have favorable safety profiles with the most commonly reported side effects being mild to moderate.

There have been reports of a rare type of adverse event following the use of the Johnson and Johnson vaccine that suggest an increased risk of a condition called thrombosis (blood clotting) with thrombocytopenia syndrome (TTS) (low blood platelets). This adverse event is very rare, occurring at a rate of about 7 per 1 million vaccinations, and has been reported more commonly in women between 18 and 49 years old. A thorough review by the CDC Advisory Committee on Immunization Practices (ACIP) of all available data shows that the vaccine’s known and potential benefits outweigh its known and potential risks.

In considering the risks and benefits of the vaccines, individuals should consider the risks of COVID-19 disease and its complications while weighing the protective effects of the vaccines and their social and interpersonal benefits.

Vaccine safety data are being monitored in order to determine longer term safety profiles.

The most common sides events reported have been mild to moderate. These side effects include pain or swelling at the injection site, fatigue, chills, muscle aches, and headaches. Most of these side effects resolve promptly.

Rare severe allergic reactions (e.g., anaphylaxis) after the Moderna and Pfizer vaccines and cases of blood clotting with low platelets after the Johnson and Johnson vaccine have been reported. However, these have been shown to be extremely rare and the associated risk has been shown to be much lower than the risk of getting COVID-19.

On April 23, 2021, the CDC Advisory Committee on Immunization Practices recommended the use of the Johnson and Johnson vaccine be resumed in adults 18 years and older under the FDA’s Emergency Use Authorization. In addition, the Committee recommended that a warning about the rare, but potentially dangerous blood clotting disorder be added to the label of the vaccine. This is to promote awareness, particularly among women aged 49 and younger, of the rare but increased risk of the blood clotting event and that there are other COVID-19 vaccine options available for which this risk has not been seen.

The risk has been observed to be the highest in women aged 18-49. Therefore, if you fall within this category and receive the Johnson and Johnson vaccine, it is recommended that you be cognizant of the possible symptoms associated with this rare adverse event for 2-3 weeks after vaccination. These include severe or persistent headaches or blurred vision, shortness of breath, chest pain, leg swelling, persistent abdominal pain, easy bruising or tiny blood spots under the skin beyond the injection site. The complete CDC recommendation for use can be found here.

No, receiving the vaccine can in no way cause COVID-19.

All three of the vaccines currently in use in the US have been shown to substantially reduce spread of the virus.

Yes, the trials included groups who are at high risk for COVID-19, including those who are 65 years and older, have underlying medical conditions (such as diabetes, high blood pressure, obesity), among others. 

The duration of protection from COVID-19 provided by these three vaccines is not known as of yet. However, the ongoing monitoring of the clinical trial participants has shown that protective effects of the vaccine are still evident 6 months after vaccination. Researchers will continue to monitor study participants to determine the duration of protection.  

Pfizer and Moderna vaccines require two doses to be effective. The second dose of the Pfizer vaccine is administered three weeks after the first dose while the second dose of the Moderna vaccine is administered four weeks after the first.

Johnson & Johnson requires one single dose.

The Pfizer and Moderna vaccine studies found that two doses were needed to optimize the immune response and provide the best possible protection from COVID-19. Therefore, the 2-dose series is strongly recommended and will be necessary for documentation of full vaccination.

No, the CDC recommends against this approach. This was not evaluated and there is no evidence that the vaccines are interchangeable. If you get a first dose of one vaccine, you should get a second dose of the same vaccine. Individuals administering the vaccine will be tracking this issue.

According to CDC guidance, second doses administered within a grace period of 4 days from the recommended date for the second dose are considered valid; however, doses administered earlier do not need to be repeated. The second dose should be administered as close to the recommended interval as possible. However, there is no maximum interval between the first and second dose for either vaccine.

Currently, the safety of any vaccine combination has not been determined and therefore the CDC advises against the mixing of COVID-19 vaccines. Research regarding the potential need for a booster injection of a COVID-19 or routine vaccination is underway.

According to the CDC, given the lack of data on the safety and efficacy of mRNA COVID-19 vaccines administered simultaneously with other vaccines, the vaccine series should routinely be administered alone, with a minimum interval of 14 days before or after administration with any other vaccine. However, mRNA COVID-19 and other vaccines may be administered within a shorter period in situations where the benefits of vaccination are deemed to outweigh the potential unknown risks of vaccine co-administration (e.g., tetanus toxoid-containing vaccination as part of wound management, rabies vaccination for post-exposure prophylaxis, measles or hepatitis A vaccination during an outbreak) or to avoid barriers or delays to mRNA COVID-19 vaccination (e.g., in long-term care facility residents or healthcare personnel who received influenza or other vaccinations prior to/upon admission or onboarding). If mRNA COVID-19 vaccines are administered within 14 days of another vaccine, doses do not need to be repeated for either vaccine.

Preliminary evidence suggests that the vaccines authorized for use in the US provide good coverage for the virus variants identified thus far in the country.

Yes, as per CDC recommendations, vaccination should be offered to persons regardless of history of prior symptomatic or asymptomatic coronavirus infection, including a positive antibody test. For persons who experience lingering symptoms for weeks and months after diagnosis (i.e., “COVID-19 long-haulers”), vaccination is similarly considered safe and likely efficacious.

For persons with current COVID-19, vaccination should be deferred until recovery from acute illness.


Per CDC and FDA recommendations, those who have had a severe allergic reaction (e.g., anaphylaxis) to any component of the vaccines should not be vaccinated. For those who have had a severe allergic reaction to another vaccine or injectable treatment (intramuscular, intravenous, or subcutaneous) the vaccine can still be administered; however, it is recommended that the risks be discussed with a healthcare provider and that the recipient be monitored for 30 minutes post-vaccination. For those with any other allergy (e.g. food, pollen, pets), vaccination should be offered. All individuals who received vaccines should be observed for about 15 minutes after vaccination.

The Pfizer and Moderna vaccines are very similar in composition. They consist of the mRNA particle, water, lipids, salt, sugar, and FDA-approved buffers. A complete list of the ingredients can be found here for Pfizer (page 2) and here for Moderna (page 2). The ingredients of the Johnson and Johnson vaccine can be found here (page 2).

None of the vaccines in use in the US contain live virus.

Currently, there are no data on the safety or efficacy of COVID-19 vaccination in persons who received monoclonal antibodies or convalescent plasma for prevention or treatment of COVID-19. Therefore, it is recommended that vaccination be deferred for at least 90 days after receiving such interventions to avoid interference with vaccine-induced immune responses.

Persons who have been identified recently as a close contact of someone with COVID-19 should defer vaccination until quarantine period has ended to avoid exposing healthcare personnel or other persons during vaccination visit.

Studies of the Moderna and Pfizer vaccines have resulted in reassuring safety results for pregnant or breastfeeding women. A discussion with a healthcare provider can help inform this decision.

Additionally, there is no recommendation for routine pregnancy testing before receipt of a COVID-19 vaccine. Those who are trying to become pregnant do not need to avoid pregnancy after COVID-19 vaccination. Again, a consultation with a healthcare provider is recommended in making this decision.

According to CDC recommendations, the vaccine may be administered to persons with underlying medical conditions who have no contraindications to vaccination. This guidance is based on the studies that have demonstrated similar safety and efficacy profiles in persons with underlying medical conditions compared to those without such conditions.

For those who are immunocompromised, safety and efficacy of vaccine has yet to be determined given the limited data for these groups. However, immunocompromised persons may still receive COVID-19 vaccines, with counseling, unless otherwise contraindicated given increased risk for COVID-19.


At this point in time, children under 16 years of age are not considered a priority group for early phases of vaccination given their low risk for severe disease.

Note that children who are 16 and 17 years old, should only receive the Pfizer vaccine at this stage. 

Under federal law, manufacturers and distributors of COVID 19 vaccines are entitled to immunity as long as there is no willful misconduct.

Questions About Getting Vaccinated (who, where, cost, etc.)

The vaccines are currently being distributed to states in the U.S., and then from the states to various counties and municipalities. Check the New York State eligibility website for the latest information.

Eligibility for COVID-19 vaccination has expanded in New York State to 16 years of age and older.

The University is currently operating four locations that provide vaccinations to Columbia affiliates, two of which can offer vaccine to their family members, as well as to other patients. As of now, these sites will be open this summer. If locations change, Columbia Health will let you know.

  • Morningside campus appointments at Lerner Hall can be made through Columbia Health. Booking an appointment can be done via the scheduling section of the Columbia Health Patient Portal. All appointments are considered tentative and subject to vaccine availability. 
  • CUIMC and ColumbiaDoctors locations appointments can be made via vaccinetogetherny.org or through your Connect account (if you use ColumbiaDoctors providers). The locations include: Black Building at 650 W 168th Street, 51 W. 51 Street, and 2702 Broadway.

All New York City sites currently do not require appointments. Visit COVID-19 Vaccine Finder or call one of these numbers: for New York City, dial (877) VAX- 4NYC (1-877-829-4692); for elsewhere in New York State, dial (833) NYS-4-VAX (1-833-697-4829).

Vaccination provided at Columbia University, New York Presbyterian Hospital or through ColumbiaDoctors practices will be at no cost to faculty, staff, and students.

The University complies with all New York Labor Laws, including 196-C, which provides for paid time off (PTO) to receive COVID-19 vaccine injections. Columbia’s policy concerning this PTO can be found on the University Policies website, located here.

Medical expenses will be covered by insurance. If you work for Columbia and are covered under a Columbia insurance program, those expenses will be paid under your insurance plan.

Vaccine uptake and safety monitoring is being conducted by the CDC, FDA and city and state health departments.

Vaccinated individuals receive a CDC vaccination card that includes that COVID-19 vaccine you received, the date you received it, and where you received it. Individuals vaccinated outside of the US may have been provided with different documentation.

Yes. You will be provided with information regarding the vaccine, including contraindications to receiving the vaccine, and need to provide consent prior to vaccination.

Under federal law, manufacturers and distributors of COVID 19 vaccines are entitled to immunity from suit as long as there is no willful misconduct. Under federal law, you cannot sue FDA for approving the vaccine.

Questions About Post-Vaccination (masking, social distancing, Covid testing, etc.)

As per the CDC guidance, fully vaccinated individuals no longer need to wear face covering/masks while gathering or conducting activities outdoors except in certain crowded settings and venues. However, individuals may still choose to continue to wear face covering/masks and observe physical distancing and this choice should be respected. See full CDC guidance for vaccinated individuals here.

As per the CDC guidance, the only exceptions to face covering/ mask wearing and physical distancing while indoors is when gathering with other fully vaccinated individuals (considered to be 2-weeks after final dose) or a single other unvaccinated household with no individual at high risk for complications of COVID-19.

Yes, all individuals at present, including those vaccinated, will need to continue to participate in the University testing program (e.g. gateway, sampling, mandatory testing).

Yes, all individuals, including those vaccinated, must participate in the Required University Protocols for coming to campus. 
1. Read the Enhanced University Health and Safety Policy
2. Read and Sign the Health Compact
3. Take Safety Training
4. Self-quarantine, if required
5. Get Tested as per Columbia testing program
6. Complete the Daily Symptom Self-check

In general, a person is considered protected 2 weeks after their second dose in a 2-dose series and 2 weeks after a single-dose vaccine. This allows the body to build up immunity to the disease. However, it is not necessary for one to quarantine between each dose. Individuals are recommended to continue with their daily lives while following COVID-19 public health recommendations.

Asymptomatic individuals who have been vaccinated are not required to quarantine after exposure to a person with COVID-19, if the following criteria are met:

  • Fully vaccinated (defined as being 2 or more weeks after the final dose (e.g., first for Janssen/Johnson & Johnson, second for Pfizer and Moderna) of the vaccine approved by the FDA or authorized by the FDA for emergency use. Vaccines that are not authorized by the U.S. Federal Drug Administration (FDA) for emergency use or approved by the FDA do not satisfy this definition).
  • While not required to quarantine, vaccinated individuals must still:
    • Monitor for symptoms for 14 days.
    • Follow all other guidance including face coverings, hand washing, and social distancing.
    • Immediately self-isolate if any symptoms develop and report the symptoms to [email protected].

Questions About Columbia's Vaccine Requirements (which vaccines, who, documentation, etc.)

Yes, the University is currently operating five locations that provide vaccinations to Columbia affiliates, two of which can offer vaccine to their family members, as well as to other patients. 

  • Morningside campus appointments at Lerner Hall can be made through Columbia Health. Booking an appointment can be done via the scheduling section of the Columbia Health Patient Portal. All appointments are considered tentative and subject to vaccine availability.  
  • CUIMC and ColumbiaDoctors locations appointments can be made via Vaccinetogetherny.org or through your Connect account (if you use ColumbiaDoctors providers). The locations include: Black Building at 650 W 168th Street, 51 W. 51 Street, and 2702 Broadway. 

All of the Columbia-operated sites will offer the specific vaccines based on availability.

On April 19, 2021, the University announced that the COVID-19 vaccination will be mandatory for all students who are present on campus, starting this fall 2021. Religious and medical exemptions will be provided in accordance with New York State public health laws.

For all other Columbia affiliates, the University is strongly recommending vaccination for those who are eligible.

Columbia joins more than 50 other universities and colleges in requiring students to be vaccinated.  This will enable a safe return to a full in-person academic and social environment by the beginning of the fall 2021 term.  There is now also ample evidence that COVID-19 vaccines prevent COVID-19 illness and the spread of the coronavirus.

We strongly recommend that all students, including international students, be vaccinated as soon as possible and receive the full dose series for optimal protection.

Columbia has mandated vaccination for all students coming onto campus for the Fall 2021 semester. Please see the Columbia policy update here for more information.  

According to the CDC, individuals who received a full series of a vaccine currently authorized for emergency use by the World Health Organization (WHO) do not need any additional doses with an FDA-authorized COVID-19 vaccine.

For individuals who were partially vaccinated with a WHO-authorized vaccine or who were vaccinated with a vaccine not authorized for emergency use by the WHO, a full series of an FDA-authorized COVID-19 vaccine can be administered with a minimal interval of 28-days post vaccination with a non-FDA-authorized vaccine.

It is Columbia’s intention to follow CDC guidance regarding individuals who may need additional vaccination in order to meet Columbia’s vaccination mandate for the Fall semester.

Starting this fall, the COVID-19 vaccination will be mandatory for all students who are present on campus. Religious and medical exemptions to vaccination will be provided in accordance with New York State public health laws.

For all other Columbia affiliates, the University is strongly recommending vaccination for those who are eligible. 

You do not need to get the vaccine as long as you do not seek admittance to any University building.