How Long Do You Need To Wait For The COVID-19 Vaccine To Work?

The COVID-19 vaccines are quite effective at preventing the virus, about 95 percent for the Moderna vaccine and the Pfizer-BioNTech vaccine, which are the two options at the moment — but they don't give you full protection immediately. You have to get two shots of either vaccine for them to work properly, and those two doses have to be given at specific intervals (via the CDC). 

If you get your first vaccine shot from Moderna, you'll need to get your second shot 28 days later. If you get your first shot from Pfizer-BioNTech, you'll need to get your second shot 21 days later. Doctors giving the vaccines are making sure they stick to these guidelines as closely as they possibly can. You need to get both doses from the same manufacturer, so if you get your first dose from Moderna, you need to get your second dose from them as well.

Your body needs time to build up immunity from COVID-19 with these vaccinations. It doesn't happen right away, but about a few weeks after getting your second dose, the vaccine should be doing its job. But remember, everyone is different, and this time frame can vary from person to person. That's why you need to continue to take precautions (via the CDC).

Keep protecting yourself and others after your vaccine

You need to continue taking all of the recommended precautions to protect yourself and others, even after getting both shots of the COVID-19 vaccine. That means continuing to wear a masksocial distanceavoid crowded or poorly ventilated spaces, and frequently washing your hands (via the CDC). 

Why? This virus and the vaccines are new. While the vaccines will protect you from getting COVID-19, and it's up to 95 percent effective when completed, experts don't know how long that protection lasts or if that keeps you from spreading the virus. You could be a carrier of the virus or have an infection with no symptoms, possibly transmitting it to others. 

More and more studies are being done on people who have and haven't been vaccinated to examine how long it's effective and whether the vaccines protect those completely vaccinated from spreading COVID-19 to others. There are also new strains of COVID-19 popping up, and experts need to study those and how effective the vaccines are against them. Until experts know more, everyone needs to keep taking the precautions listed above.