FAQs: Immunizations During COVID-19

There are lots of questions popping up about vaccinations in light of the COVID-19 pandemic. There are also many similarities between flu and COVID-19. The chart below answers common questions about vaccinations during the COVID-19 pandemic. The last page of the document helps to clarify similarities and differences between influenza and COVID-19.


Answer/Pertinent Information

Should vaccinations be delayed due to the COVID-19 pandemic?

Defer outpatient vaccinations of ALL people with known or suspected COVID-19 until they meet criteria to stop isolation. This is to avoid exposing healthcare workers or other people to SARS-CoV-2.1 Hospitalized patients may be vaccinated prior to discharge, as they are already interacting with healthcare workers.

  • Follow current government guidance on isolation recommendations (e.g., until at least ten days after COVID-19 symptoms began, AND fever-free for 24 hours [without fever-reducing meds], AND other symptoms improving per CDC).13

Do NOT delay routine vaccinations in non-infected people simply because of the COVID-19 pandemic (even if patients are complying with social distancing recommendations).1

  • Reassure patients that vaccines do not weaken the immune system.
  • Staying current with recommended vaccines can conserve healthcare resources by reducing illnesses.3

Guidance for vaccinations during the pandemic can be found at:

Access current vaccination schedules here:

Why is it important to get the influenza vaccine during COVID-19?

In light of COVID-19, it’s more important than ever to get a flu vaccine, even if social distancing.3

  • It is not known how long social distancing will be recommended, so it’s best to provide protection.
  • The flu vaccine won’t protect against COVID-19, but getting the flu vaccine can help conserve healthcare resources, by reducing the risk of flu illnesses, hospitalizations, and death.3
  • Getting the flu vaccine may reduce office or emergency department visits, which might also reduce SARS-CoV-2 exposure.

Use our resource, Vaccine Adherence: Addressing Myths and Hesitancy, to help encourage vaccination.

In addition, getting the flu vaccine can help reduce symptom confusion between flu and COVID-19.18 See the last page of this document for a comparison of symptoms, contagiousness, and complications for flu and COVID-19.

Do any vaccines help to boost immunity against COVID-19?

Some experts theorize that live vaccines (e.g., MMR) may provide some protection against COVID-19. The theory is that live-attenuated vaccines lead to induction of interferons and activated natural killer cells leading to “natural immunity” against COVID-19.2,8

  • However, there are NOT data available to confirm that MMR or any other live vaccine actually protects against COVID-19.8 Clinical trials are planned and ongoing.11,12

Currently available and commonly used live vaccines include measles, mumps, and rubella (MMR); measles, mumps, rubella, and varicella (MMRV); varicella; zoster; FluMist and rotavirus.

Do the pneumococcal vaccines protect against pulmonary aspects of COVID-19?

The SARS-CoV-2 virus can lead to lung complications, such as pneumonia.6

Vaccines against pneumonia (e.g., Pneumovax 23, Prevnar 13) protect against bacterial pneumonia and do NOT provide protection against COVID-19, viral pneumonia, or pneumonia caused by COVID-19.4-6 However, some patients with COVID-19 may get a secondary pneumococcal pneumonia.7

Ensure patients are current with their pneumococcal vaccine. Pneumococcal vaccination may reduce the risk of secondary bacterial pneumonia in patients with COVID-19 or influenza. See our pneumococcal vaccination charts (U.S.; Canada) to find out which adults should get which pneumococcal vaccine and when.

How should patients be counseled who experience a “flu-like” reaction to a vaccine during the COVID-19 pandemic?

Any vaccine can cause side effects, including fever.14

  • Vaccine-associated fever usually begins within 12 hours of vaccination and can last up to three days.1,15
    • Fever typically resolves within one to two days for most vaccines (e.g., diphtheria/tetanus/pertussis [DTaP], hepatitis A, influenza, pneumococcal).20
    • Fever can last for up to three days after receiving certain vaccines (e.g., Shingrix).1
  • Advise giving acetaminophen or ibuprofen as needed for fever, especially if higher than 102°F (39°C).15

Advise people who develop fever after a vaccine to stay home until the fever goes away. Patients should contact their prescriber if they develop new symptoms (e.g., cough, shortness of breath, loss of taste or smell) or fever persists for more than a day or so after vaccination.1

What can we expect with the COVID-19 vaccine?

At the time of publication, there are not any COVID-19 vaccines available. However, current information about ongoing COVID-19 vaccine trials can be found at https://clinicaltrials.gov/ or https://www.who.int/publications/m/item/draft-landscape-of-covid-19-candidate-vaccines.

It is currently expected that a COVID-19 vaccine will likely be an intramuscular (IM) injection, probably require two doses to complete the vaccination, and possibly require reconstitution or frozen storage.

Some COVID-19 vaccines in the pipeline use new technology such as genetically engineered ribonucleic acid (RNA) or deoxyribonucleic acid (DNA) to trigger an immune response.

Review the CDC’s COVID-19 Vaccination Program Interim Playbook for Jurisdiction Operations to start planning for COVID-19 vaccine administration (https://www.cdc.gov/vaccines/imz-managers/downloads/COVID-19-Vaccination-Program-Interim_Playbook.pdf).


Flu vs COVID-19




Shared symptoms

• fever/chills
• cough
• shortness of breath/difficulty breathing
• fatigue (feeling tired)
• sore throat
• runny/stuffy nose
• muscle pain/body aches/headache
• vomiting/diarrhea (less common, though more common in kids vs adults)

Unique symptoms


Loss of taste or smell

Symptom onset

~1 to 4 days after being infected

~5 days after being infected (ranges from ~2 to 14 days)


Virus can spread from about ~1 day before symptoms appear through ~7 days (most contagious in first 3 to 4 days; infants and people with a weakened immune system may be contagious even longer).

Virus can spread from ~2 days before symptoms appear through as long as 10 days after testing positive for, or first symptoms of, COVID-19.

More contagious among certain populations/age groups than flu.

More prone to “super spreading” (i.e., transmission to an unusually large number of people by a relatively small number of highly contagious people).

Unique severe complications

Long-term inflammatory complications:

  • myocarditis
  • encephalitis
  • myositis/rhabdomyolysis
  • multiorgan failure

We are still learning about COVID-19 complications. Currently we know COVID-19 can lead to:

Blood clots

Long-term damage to:

  • heart
  • lungs
  • kidneys
  • brain

School-aged children rarely develop Multisystem Inflammatory Syndrome in Children (MIS-C)

Prepared by the Editors of Therapeutic Research Center (361001).


  1. Immunization Action Coalition. Ask the experts: COVID-19 and routine vaccination. Updated June 11, 2020. https://www.immunize.org/askexperts/experts_covid19.asp. (Accessed September 2, 2020).
  2. Anbarasu A, Ramaiah S, Livingstone P. Vaccine repurposing approach for preventing COVID-19: can MMR vaccines reduce morbidity and mortality? Hum Vaccin Immunother 2020 June 5;1-2. Doi: 10.1080/21645515.2020.1773141.
  3. CDC. Influenza (flu). Frequently asked influenza (flu) questions 2020-2021 season. Updated August 31, 2020. https://www.cdc.gov/flu/season/faq-flu-season-2020-2021.htm. (Accessed September 2, 2020).
  4. World Health Organization. Coronavirus disease (COVID-19) advice for the public: mythbusters. https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public/myth-busters#:~:text=No.%20Vaccines%20against%20pneumonia,to%20protect%20your%20health. (Accessed September 2, 2020).
  5. Galiatsatos P. What Coronavirus does to the lungs. April 13, 2020. https://www.hopkinsmedicine.org/health/conditions-and-diseases/coronavirus/what-coronavirus-does-to-the-lungs. (Accessed September 2, 2020).
  6. American Lung Association. Coronavirus (CoV). https://www.lung.org/lung-health-diseases/lung-disease-lookup/coronavirus. (Accessed September 2, 2020).
  7. Cucchiari D, Pericas JM, Riera J, et al. Pneumococcal superinfection in COVID-19 patients: a series of 5 cases. Med Clin (Barc) 2020 Jun 5;S0025-7753(20)30349-3. doi: 10.1016/j.medcli.2020.05.022.
  8. Fidel PL, Noverr MC. Could an unrelated live attenuated vaccine serve as a preventive measure to dampen septic inflammation associated with COVID-19 infection? mBio 2020;11(3):e00907-20.
  9. CDC. Influenza (flu): similarities and differences between flu and COVID-19. August 31, 2020. https://www.cdc.gov/flu/symptoms/flu-vs-covid19.htm. (Accessed September 2, 2020).
  10. World Health Organization. Q&A: influenza and COVID-19 – similarities and differences. March 17, 2020. https://www.who.int/emergencies/diseases/novel-coronavirus-2019/question-and-answers-hub/q-a-detail/q-a-similarities-and-differences-covid-19-and-influenza. (Accessed September 2, 2020).
  11. ClinicalTrials.gov. Measles vaccine in HCW (MV-COVID19). NC04357028. July 16, 2020. https://clinicaltrials.gov/ct2/show/NCT04357028?term=MMR&cond=Covid19&draw=2&rank=1. (Accessed September 2, 2020).
  12. ClinicalTrials.gov. CROWN CORONATION: COVID-19 research outcomes worldwide network for coronavirus prevention (CROWN CORONA). September 9, 2020. https://clinicaltrials.gov/ct2/show/NCT04333732?term=MMR&cond=Covid19&draw=2&rank=2. (Accessed September 9, 2020).
  13. CDC. Coronavirus disease 2019 (COVID-19). Discontinuation of isolation for persons with COVID-19 not in healthcare settings. July 20, 2020. https://www.cdc.gov/coronavirus/2019-ncov/hcp/disposition-in-home-patients.html. (Accessed September 3, 2020).
  14. CDC. Vaccines & Immunizations. Possible side effects from vaccines. April 2, 2020. https://www.cdc.gov/vaccines/vac-gen/side-effects.htm. (Accessed September 3, 2020).
  15. Seattle Children’s. Immunization reactions. August 14, 2020. https://www.seattlechildrens.org/conditions/a-z/immunization-reactions/#:~:text=Fever%20with%20most%20vaccines%20begins%20within%2012%20hours%20and%20lasts,product%20(such%20as%20Advil). (Accessed September 3, 2020).
  16. CDC. Coronavirus disease 2019 (COVID-19). People with certain medical conditions. https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/people-with-medical-conditions.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fcoronavirus%2F2019-ncov%2Fneed-extra-precautions%2Fgroups-at-higher-risk.html. (Accessed September 15, 2020).
  17. CDC. Influenza (flu). People at high risk for flu complications. September 9, 2020. https://www.cdc.gov/flu/highrisk/index.htm. (Accessed September 15, 2020).
  18. Grohskopf LA, Alyanak E, Broder KR, et al. Prevention and control of seasonal influenza with vaccines: recommendations of the Advisory Committee on Immunization Practices — United States, 2020–21 influenza season. August 21, 2020. https://www.cdc.gov/mmwr/volumes/69/rr/rr6908a1.htm. (Accessed September 15, 2020).
  19. Maragakis LL. Coronavirus disease 2019 vs. the flu. Updated September 15, 2020). https://www.hopkinsmedicine.org/health/conditions-and-diseases/coronavirus/coronavirus-disease-2019-vs-the-flu. (Accessed September 15, 2020).
  20. Ahn SH, Zhiang J, Kim H, et al. Postvaccination fever response rates in children derived using a fever coach mobile app: a retrospective observational study. https://mhealth.jmir.org/2019/4/e12223/. (Accessed September 17, 2020).

Cite this document as follows: Clinical Resource, FAQs: Immunizations During COVID-19. Pharmacist’s Letter/Prescriber’s Letter. October 2020.

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