QUESTION: Are the COVID-19 mRNA vaccines safe since they were developed in a short amount of time?

ANSWER: Yes, the COVID-19 mRNA vaccines are safe despite that the time of vaccine development was short. COVID-19 mRNA vaccines have been tested to show they are safe and effective. The testing was the same as it has been for other vaccines before it was approved for emergency use in the United States by the EUA. mRNA technology is new to the public but it has been studied for decades. mRNA vaccines were researched for influenza, Zika, rabies, and cytomegalovirus (CMV). mRNA vaccines do not contain a live virus. You will not contract COVID-19 from receiving the COVID-19 vaccine.

When can I get vaccinated with COVID 19 Vaccines?

What are the new COVID 19 vaccines approved for emergency use in the US?

As of February 10, 2021, there are two COVID-19 vaccines approved in the US.

  • Pfizer-BioNTech COVID-19 Vaccine
  • Moderna COVID-19 Vaccine
How does mRNA vaccine work?

mRNA vaccines give instructions to your body to make antibodies to a harmless protein that is specific to the coronavirus. After our bodies make these antibodies the instructions that were injected are broken down and eliminated.

How effective is it?

Pfizer-BioNTech COVID-19 Vaccine efficacy is 95% after 2 doses completed. Moderna COVID-19 Vaccine efficacy is 94.1% after 2 doses completed.

What should I do if I did not get my second dose on schedule (Pfizer-BioNTech is 21 days later and Moderna is 28 days later)

The second dose should be administered as close to the recommended interval as possible. If you missed the second dose within the recommended interval you will not need to restart the series.

Who is recommended to receive COVID-19 Vaccines?

Anyone who is 16 years and older can receive Pfizer-BioNTech COVID-19 vaccine and those 18 years and older are eligible to receive Moderna COVID-19 vaccine.

Talk to a doctor or pharmacist if you have a severe allergic reaction (e.g., anaphylaxis) or immediate allergic reaction after a previous dose of an mRNA COVID-19 vaccine or any of its components (including  polyethylene glycol [PEG]). You are not eligible for receiving COVID-19 vaccines.

If you have ever had any severe or immediate allergy you will be asked to wait for 30 minutes after your vaccine. All other persons will be asked to wait for 15 minutes for observation.

Do I have to get the same vaccine for the second dose as I did for the first dose of COVID-19 vaccine?

Yes, you will receive the same vaccine for your first and second dose. The second dose is to boost the immune system to fight off COVID-19 virus.

What are the possible side effects of COVID-19 Vaccines?

COVID-19 Vaccines are usually very well tolerated. If side effects do occur, they are typically  injection site reactions (pain or swelling), fatigue, fever, chills, and headache which are usually considered mild and resolve within 1-3 days.

What should I do if I experience side effects of COVID 19 vaccines such as fever, headache, muscle pain?

Most post-vaccination symptoms are mild to moderate and arise within the first 3 days of vaccination and resolve within 1-3 days of onset. The symptoms are more frequent and common among younger persons compared to older persons after the second dose being administered.

To manage post-vaccination symptoms, medications that can relieve pain or fever (e.g. acetaminophen [Tylenol], non-steroidal anti-inflammatory drugs (NSAIDs) [Ibuprofen] may be taken. However, routinely taking these medications for preventing post-vaccination symptoms is not currently recommended.

V-Safe: a smartphone-based tool that uses text-messaging and web surveys to provide daily and weekly check-ins to report any signs and symptoms of adverse effects. It also gives you a 2nd dose reminder.

Prepared by Gem Chan PharmD Candidate 2021


CDC Understanding and explaining mRNA COVID-19 Vaccines (2020, Nov. 24)

CDC Interim Clinical Considerations for Use of mRNA COVID-19 Vaccines Currently Authorized in the United States (2021, Jan. 21)