How long after the second dose of the COVID-19 vaccine is it effective?

Nexstar Media Wire

Updated: Mar 13, 2021 / 12:02 PM CST

FILE – In this Thursday, March 11, 2021, file photo, a health worker loads syringes with the vaccine on the first day of the Johnson & Johnson vaccine being made available to residents at the Baldwin Hills Crenshaw Plaza in Los Angeles. California officials say much of the state will be able to reopen next week to indoor activities as coronavirus case rates remain low. At the same time, more than 4 million residents with certain disabilities or health concerns become eligible for a vaccine. (AP Photo/Damian Dovarganes, File)

(NEXSTAR) — When you receive the second and final shot of the Pfizer and Moderna vaccines, you must wait some time before the vaccines reach full effectiveness.

The Centers for Disease Control and Prevention says it takes about two weeks after the second shot of both the Pfizer and Moderna vaccines for them to be effective.

After the first shot, you’re only somewhat protected.

Studies have shown that a single shot of the Pfizer vaccine is 52-percent effective at preventing COVID-19 infection.

The Moderna vaccine is thought to be 80.2-percent effective after a single dose, according to a document the vaccine manufacturer submitted to the FDA.

After receiving two doses of either shot, you should be 95-percent protected.

On Monday, the CDC released new guidelines that say it is safe for fully vaccinated people to gather without masks. Those guidelines, however, don’t apply until the vaccine has reached full efficacy.

The CDC guidance is designed to address growing demand, as more adults have been getting vaccinated and wondering if it gives them greater freedom to visit family members, travel, or do other things like they did before the COVID-19 pandemic swept the world last year.

“With more and more people vaccinated each day, we are starting to turn a corner,” said CDC Director Dr. Rochelle Walensky.

During a press briefing Monday, she called the guidance a “first step” toward restoring normalcy in how people come together. She said more activities would be OK’d for vaccinated individuals once caseloads and deaths as the country nears herd immunity and the science emerges on the ability of those who have been vaccinated to get and spread the virus.

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The CDC is continuing to recommend that fully vaccinated people still wear well-fitted masks, avoid large gatherings, and physically distance themselves from others when out in public. The CDC also advised vaccinated people to get tested if they develop symptoms that could be related to COVID-19.

The CDC guidance did not speak to people who may have gained some level of immunity from being infected, and recovering from, the coronavirus.

About 31 million Americans — or only about 9% of the U.S. population — have been fully vaccinated with a federally authorized COVID-19 vaccine so far, according to the CDC.

The Associated Press contributed to this report.