Vaccine and Quarantine

On February 10, the CDC updated quarantine guidance for vaccinated individuals exposed to COVID-19, giving some people a get out of jail free card.

According to the new guidance, individuals who received their second FDA authorized mRNA vaccine injection between 14 and 90 days ago need not quarantine after exposure to COVID-19 provided they are symptom free.

An exposure is still defined as an encounter of more than 15 minutes and less than 6 feet with someone infected by SARS-CoV-2 when one or both individuals are not wearing a mask.  Provided that there is no fever or other indications of upper respiratory infection in the exposed individual, quarantine is not necessary for those who received both doses of either the Pfizer or Moderna vaccine more than two weeks before the exposure.  However, vaccinated individuals should monitor for symptoms (i.e., take daily temperatures) for 14 days after exposure, and should quarantine immediately if symptoms (i.e., fever) develop.  This reduced quarantine requirement does not apply to individuals who complete a vaccination series which has not receive an EUA from the FDA, such as vaccines approved in countries outside the United States.

If it has been more than two weeks since you completed a vaccine series, then you benefit from reduced quarantine requirements after exposure.  But you don’t get to party like it’s 2019!  You may still be able to spread the virus to others, so you must still mask and social distance in public.  Furthermore, no one knows how long vaccine-induced immunity will last.

The CDC maintains that natural immunity—immunity from infection—lasts for at least 90 days.  It may last longer, but the CDC is still unwilling to say so.  Since the CDC’s new quarantine exemption also expires after 90 days, it seems reasonable to infer that 90 days may be the outer limits of immunity, whether from previous infection or vaccination.  We may hope that it’s longer, but so far, the CDC has not said so.

So what does all this mean?  If it has been more than two weeks since you completed Pfizer or Moderna vaccination series, you have a get out of quarantine jail free card—you don’t have to quarantine after a potential exposure if you are symptom free.  However, a vaccination does not make you special in any other way.  You must monitor for symptoms for 14 days after exposure.  You must quarantine immediately if you have symptoms.  You must continue to mask and keep apart in public.  In other words, even if you have completed a vaccination series, you don’t have this card:

At least not yet.