If I’m vaccinated, why do I need to get a COVID test?
If you’ve been around someone who has COVID-19, you need to get tested even if you’re vaccinated.
The latest guidance from the U.S. Centers for Disease Control and Prevention says people who are fully vaccinated should get tested three to five days after a potential exposure, even if they don’t have symptoms. That change comes two months after the agency eased its initial testing guidance.
In May, the CDC said vaccinated people face very little risk of serious illness and don’t need to be tested in most cases, even if exposed to someone who was sick. The thinking was that vaccinated people also weren’t likely to spread COVID-19 to others.
But the agency says it’s reversing that guidance because of the more contagious delta variant, which now accounts for most COVID-19 infections.
The COVID-19 vaccines are still very good at protecting people from getting seriously ill, but the CDC says new data shows vaccinated people infected with the delta variant could spread it to others.
Doctors, nurses and other healthcare workers should consult with their employers, some of whom may require routine testing for their staff. People working in prisons and homeless shelters are also generally subject to stepped-up testing requirements.
U.S. citizens returning from abroad still have to present a negative COVID-19 test before boarding their flights home, regardless of their vaccination status. Anyone who tests positive for COVID-19 should still isolate for 10 days, the CDC says.
What is meant by a ‘breakthrough’ case of COVID?
A “breakthrough infection” is when a fully vaccinated person gets infected with the coronavirus.
In studies, the two-dose COVID-19 vaccines by Pfizer and Moderna were around 95% effective at preventing illness, while the one-shot Johnson & Johnson shot was 72% effective, though direct comparisons are difficult.
So, while the vaccines are very good at protecting us from the virus, it’s still possible to get infected with mild or no symptoms, or even to get very sick.
If you do end up getting sick despite vaccination, experts say the shots help reduce the severity of the illness — the main reason to get vaccinated.
But the understanding of how vaccinated people who are infected might spread the virus to others is changing.
Previously, health officials believed vaccinated people who get breakthrough infections were unlikely to spread the virus. But with the more contagious delta variant that is now dominant, the CDC said new data shows people who get infected could carry enough virus in their noses and throats to spread it to others.
The agency recently cited that data when recommending vaccinated people go back to wearing masks indoors in areas where the virus is surging.
“It is concerning enough that we feel like we have to act,” said CDC Director Dr. Rochelle Walensky.
Still, health experts say the vaccines provide strong protection against serious illness. In the U.S., people who weren’t vaccinated make up nearly all hospitalizations and deaths from COVID-19.