The CDC has issued new guidelines for people who have been fully vaccinated. You are considered fully vaccinated 2 weeks after the second dose of either the Pfizer or Moderna vaccines or 2 weeks after a single dose of the Johnson & Johnson vaccine.

If you are fully vaccinated:

  • you can now gather indoors with other fully vaccinated people without wearing a mask.
  • you can now gather indoors with unvaccinated people from one other household without masks if any of them or anyone they live with is not at risk for severe illness from COVID-19.
  • you do not need to quarantine or get tested after exposure to someone with COVID-19 unless you have symptoms (or unless you live in a group setting).

Precautions have not changed for other situations!

Much has been learned but questions like those below still remain. Real world vaccine studies should continue to provide answers that will allow more updates to CDC recommendations.

  1. How long is the vaccine effective?

Some people who had a COVID-19 infection became re-infected after 90 days. Scientists feel protection from the vaccines will last longer because of how they work but more time is needed to determine.

  1. Is the vaccine effective against new variants of the virus?

Viruses survive by mutating. Early data show vaccines may be effective against some mutations, or variants, but not others. Vaccines can easily be modified if needed to create a new version to be effective.

  1. Does the vaccine prevent transmission without infection?

It is possible you could be exposed to the virus and not become ill from it because of protection from the vaccine but you could unknowingly spread it to someone else. Early results show vaccines may help prevent this type of spread.

  1. What threshold is needed to reach herd immunity?

Herd immunity is achieved when enough people are vaccinated or have adequate antibody levels from a previous infection to then limit spread. This threshold is different for different diseases. For example, with measles the threshold is 95% of the population.

  1. How effective is the vaccine in special populations?

Clinical trials are generally conducted in healthy adult volunteers with stable pre-existing conditions. This is especially true when answers are needed quickly. Trials are now being conducted in children and use in real world environments will provide information for other conditions.

Until we know more about these questions, everyone should continue using basic prevention measures when in public or around others with unknown vaccination status or health conditions. We know these mitigation strategies work: wear a well-fitting mask that covers your nose and mouth, stay at least 6 feet away from others, avoid crowds and poorly ventilated spaces.


Submitted by: Vicky Shelton, D.Ph.