Vaccine Myths and Facts: Questions and Answers

couple wearing face masks talks on sofa while woman with notepad observes

If I’ve already had COVID-19, do I still need to get the vaccine?

Yes. Evidence continues to show that being fully vaccinated is the best protection against getting COVID-19, whether you have already had COVID-19 or not. Experts do not yet know how long you are protected from getting sick again after recovering from COVID-19. Even if you have already recovered from COVID-19, it is possible that you could be infected with the virus that causes COVID-19 again.

The messenger RNA (mRNA) technology used to make the COVID-19 vaccine seems like it is untested. Is it safe?

Yes. The mRNA technology behind the new coronavirus vaccines has been in development for almost two decades. Vaccine makers created the technology to help them respond quickly to a new pandemic illness, such as COVID-19.

Is there sufficient safety monitoring?

Yes. COVID-19 vaccines are being held to the same high safety standards as other routine vaccines. After any vaccines are authorized and in use, both FDA and CDC continue to monitor their safety.  Existing systems have been scaled up and can rapidly detect possible vaccine safety problems. These include::

  • V-safe — A new smartphone-based, after-vaccination health checker for people who receive COVID-19 vaccines. V-safe uses text messaging and web surveys from CDC to check in with vaccine recipients following COVID-19 vaccination. V-safe also provides second vaccine dose reminders if needed, and telephone follow up to anyone who reports medically significant (important) adverse events. 
  • Vaccine Adverse Event Reporting System (VAERS) — The national system that collects reports from healthcare professionals, vaccine manufacturers, and the public of adverse events that happen after vaccination; reports of adverse events that are unexpected, appear to happen more often than expected, or have unusual patterns are followed up with specific studies. 

The vaccines were developed quickly. Were they properly tested?

Yes. Researchers were able to fast-track these vaccines because they had already made progress developing vaccines for other types of coronaviruses, such as the 2003 SARS epidemic and the 2012 MERS outbreak. Researchers also used existing clinical trial networks to quickly conduct COVID-19 vaccine trials. Another critical factor has been the substantial, rapid investment in vaccine manufacturing, while research was being performed to prove vaccine effectiveness and safety.

Did researchers expect that there would be variants of coronavirus?

Yes. Variants are expected because viruses constantly change through mutation. Sometimes new variants emerge and disappear. Other times, new variants persist. All variants of the virus that causes COVID-19 are being tracked in the United States and globally during this pandemic. The best way to slow the emergence of new variants is to reduce the spread of infection by taking measures to protect yourself, including getting fully vaccinated and receiving recommended boosters.

Why are boosters needed?

Boosters are needed because the effectiveness of the vaccines appears to decline over time. If coronavirus is still in circulation in the population, and/or if new variants begin circulating, the vaccines need to be “boosted” to provide sustained protection. Data from a clinical trial show that a Pfizer-BioNTech booster shot increased the immune response in trial participants who completed their primary series of two shots of this vaccine six (6) months earlier.

How many times should people expect to have to get boosters, and will vaccines be available to do this?

Vaccine experts do not know yet how many more boosters will be needed to address COVID-19.  But vaccine researchers and manufacturers are monitoring this closely and prepared to develop and roll out any necessary boosters.

Do the vaccines cause infertility and/or disrupt menstrual cycles?

No. There is no evidence the vaccines cause infertility or disrupt menstrual cycles. However, COVID-19 infections can impact menstruation.

Do the vaccines alter human DNA?

No. The COVID-19 vaccines are designed to help your body’s immune system fight the coronavirus. The messenger RNA (mRNA) does enter cells, but not the nucleus of the cells where DNA resides. The mRNA causes the cell to make protein to stimulate the immune system, and then it quickly breaks down—without affecting your DNA.

Are the vaccines safe for pregnant people?

Yes. All currently approved COVID-19 vaccines have been recommended for use by people who are pregnant, breastfeeding, trying to get pregnant now, or might become pregnant in the future. None of the vaccines cause infection, including in pregnant people or their babies. Early data from three safety monitoring systems did not find any safety concerns for pregnant people who received an mRNA COVID-19 vaccine late in pregnancy ,or for their babies. Scientists have not found an increased risk for miscarriage among people who received an mRNA vaccine just before and during early pregnancy (before 20 weeks of pregnancy). Vaccination of pregnant people builds antibodies that might protect their baby .

Do the vaccines contain microchips and/or tracking devices, or fetal tissue?



Centers for Disease Control and Prevention; NASW Webinar: COVID-19 Vaccination Through a Social Work Lens: Myths and Facts; and, Mona Gahunia, D.O., Kaiser Permanente.

COVID-19 Vaccination through a Social Work Lens: Myths and Facts: