If you completed both doses of your COVID-19 vaccine, you may not have to quarantine after being exposed to someone who tests positive, according to the latest guidance from the CDC. This is a change in policy, and it’s based on some promising new data.
The purpose of a quarantine is to prevent someone from transmitting the coronavirus while they wait to see if they develop symptoms. (Once you know you’re sick, you’re in isolation, not quarantine.) During quarantine, as you should know by now, you need to stay home and take precautions to protect others.
Here’s the new advice from the CDC:
However, vaccinated persons with an exposure to someone with suspected or confirmed COVID-19 are not required to quarantine if they meet all of the following criteria†:
- Are fully vaccinated (i.e., ≥2 weeks following receipt of the second dose in a 2-dose series, or ≥2 weeks following receipt of one dose of a single-dose vaccine)
- Are within 3 months following receipt of the last dose in the series
- Have remained asymptomatic since the current COVID-19 exposure
Persons who do not meet all 3 of the above criteria should continue to follow current quarantine guidance after exposure to someone with suspected or confirmed COVID-19.
Notice the 3-month timeframe. It’s likely that protection from the vaccine will last longer than three months, but so far we just don’t know. If you were among the first people to get the vaccine in December, then starting sometime around March you may need to start quarantining again after exposure.
That said, the three-month period will likely be extended if we get data showing that protection lasts longer than that.
Why is this okay?
If you’re confused because you thought the vaccine still allowed people to transmit the disease, let’s take a minute to clarify.
While we’ve known for months that the COVID vaccines (both Pfizer and Moderna) are known to prevent serious disease, the clinical trials didn’t test whether vaccinated people are able to transmit the disease or not. That’s given rise to a myth that the vaccine doesn’t prevent infection, but the truth is that we just didn’t know whether it does, or by how much. Physician Megan Ranney pointed out in a Twitter thread that we actually have several studies hinting that the vaccine may halt or greatly diminish transmission.
The CDC says:
Although the risk of SARS-CoV-2 transmission from vaccinated persons to others is still uncertain, vaccination has been demonstrated to prevent symptomatic COVID-19; symptomatic and pre-symptomatic transmission is thought to have a greater role in transmission than purely asymptomatic transmission. Additionally, individual and societal benefits of avoiding unnecessary quarantine may outweigh the potential but unknown risk of transmission, and facilitate the direction of public health resources to persons at highest risk for transmitting SARS-CoV-2 to others. This recommendation to waive quarantine for people with vaccine-derived immunity aligns with quarantine recommendations for those with natural immunity, which eases implementation.
It’s a bit of a gamble, but so is every one of these high-stakes policy decisions. Requiring vaccinated people to still quarantine has its own downsides: missed work, for one.
If you are vaccinated and able to skip quarantine, the CDC recommends a few measures just in case: you should still make sure to wear a mask around others, observe all other safety protocols (like distancing), and make sure to watch yourself for symptoms. The vaccine is not 100% effective, so there’s a small chance you could get sick anyway.
Expect policies to evolve as we learn more about the vaccines and the new coronavirus variants. Australia, for example, still requires vaccinated people to quarantine before they enter the country. They’ve seen the same evidence as the CDC, but made a different judgment call. We’re all still learning some things about the strength of these vaccines against the virus, so for now the thing to do is abide by whatever rules apply to you, and wait to see how policies change.