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COVID questions: Post-vaccine precautions, ingredients, pregnancy

December 17, 2020

Editor’s note: We will be publishing answers to questions about COVID-19 and the pandemic each week in this COVID questions column. If you have a question, please email it to

Q: Once I get the vaccine, do I still need to wear a mask and social distance?

A: The vaccine is extra protection, like a super mask, but it is not perfect. Even in very controlled trials, only 90-95% of people getting the vaccine were protected from developing COVID-19, so 5-10% still got sick. And out in the world under less perfect conditions, the number of people still getting sick with COVID-19 even with a vaccine could be higher. So yes, after you get vaccinated, you still need to wear a mask, socially distance and get tested if you think you have symptoms.

This is especially true if you have only gotten one dose of the 2-dose series. At the current moment, there is not enough data to say that one dose will protect you as effectively as 2 doses. You must get the second dose to complete the series for maximum protection.

– Devlin Cole, preventive medicine resident, UW–Madison Department of Population Health Sciences, as reported in the Milwaukee Journal Sentinel.

Q: What’s in the vaccine?

A: The main ingredient of the Pfizer and Moderna vaccines is a small strand of messenger RNA (mRNA). It is synthetic and does not come from the actual SARS-CoV-2 virus. The vaccine does not contain mRNA that would allow cells to make an entire virus particle. A person who is vaccinated produces an immune response that affords protection against getting COVID-19 without being infected with the SARS-CoV-2 virus. Two doses of either the Moderna or Pfizer vaccines are needed.

– Ajay Sethi, Associate Professor, Population Health Sciences; Faculty Director, Master of Public Health Program, as reported in the Milwaukee Journal Sentinel.

Q: Is it safe for pregnant women to get the vaccine? Were they included in the trials? What about children?

A: Pregnant and breastfeeding women were not included in Pfizer and Moderna trials, so safety and efficacy numbers from the vaccine studies can’t be directly applied to this population. However, the CDC has identified that pregnancy puts women in a high-risk category for COVID-19. Pfizer included children as young as 12 years old in their trials since October. Moderna is starting to include children as young as 12 years old very soon.

– Devlin Cole, as reported in the Milwaukee Journal Sentinel.

See more answers to COVID questions at Also, visit our COVID-19 impact site.