Yes, you need the second shot

By The Health News Team | June 1, 2021
Doctor in white protective gloves putting adhesive bandage on man's arm after injection of vaccine.

A new real-world study of the Pfizer and Moderna COVID-19 vaccines found both to be highly effective in preventing COVID-19. So effective, that after just 1 dose of the 2-dose vaccines, participants' risk of coronavirus infection was reduced by 82% after 2 or more weeks post-vaccination.

However, experts are clear: don't skip the second shot. While the protection offered after just 1 dose is substantial, the vaccines are most effective when both doses are received as recommended. The study, performed by the Centers for Disease Control and Prevention (CDC), included front-line workers who have an increased risk of exposure due to their professions. It found the vaccines' effectiveness increased to 94% after 2 or more weeks from when the second dose was received.

The importance of that second shot
This increase in efficacy is because the second dose significantly boosts the level of antibodies and T-cells the body produces to fight the virus. What's more, while
additional studies have shown that the full dose of the vaccines provides protection for at least 6 months - a time frame that will likely increase as the vaccines are in use longer - it is unknown how long protection is provided from just 1 dose of the 2-dose vaccines.

"We have been concerned, and still are, that when you look at the level of protection after 1 dose, you can say it's 80%, but it is somewhat of a tenuous 80%," says Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. "When you just leave it at 1 dose, the question is: How long does it last?"

Additionally, to reach optimal effectiveness, the CDC reports the vaccine doses should be received within the recommended intervals. For the Pfizer vaccine, the interval between doses is 21 days, and the Moderna vaccine calls for a 28-day interval between the first and second dose. However, up to 42 days between doses for both vaccines is permissible when a delay is unavoidable.

First-dose side effects no excuse to skip second
While some may be hesitant to go back for their second dose of a COVID-19 vaccine if they experienced side effects after the first, the CDC says that is no excuse to skip it. People should get the second dose even if they had side effects after the first dose, unless otherwise advised by their doctor.

Possible vaccine side effects, which may include soreness at the injection site and mild flu-like symptoms, can be uncomfortable but should go away within 1 to 3 days. Over-the-counter (OTC) medications, such as ibuprofen, acetaminophen and aspirin, taken after vaccination can help relieve any pain and discomfort.

On the other hand, if someone had a severe allergic reaction, such as anaphylaxis, after getting the first dose of a COVID-19 vaccine, the CDC recommends that they do not get a second shot of that vaccine. The same is true for people who had an immediate allergic reaction - such as hives, swelling and wheezing - within 4 hours after getting the first dose, even if their allergic reaction was not severe enough to require emergency care. These individuals should talk to their doctor about any concerns they may have about getting the second dose.

After you've received your second dose
Once people have received both doses of the vaccine, and 2 or more weeks have passed after the second dose, the benefits of vaccination beyond stopping the spread of COVID-19 become clear. Several activities people participated in before the start of pandemic can once again be enjoyed.

According to the CDC, once people are fully vaccinated and in non-health care settings, they can:

  • Resume activities without wearing masks or physically distancing, except where required by federal, state or local rules and regulations, such as in face covering, where the mask mandate will remain in effect until June 15

  • Travel without a pre- or post-travel COVID-19 test, unless required by their destination, and without quarantining after travel

  • Refrain from quarantine and COVID-19 testing following a known exposure, as long as you are without any COVID-19 symptoms, known as being asymptomatic (with some exceptions for specific settings)

  • Refrain from routine COVID-19 screening testing

"We all want normalcy in America," Dr. Fauci says. "The highway to that normalcy is vaccination. And every single day, as we get 3 to 4 million people vaccinated, we get closer and closer to that normalcy."

However, medical experts emphasize that because it may still possible to become infected and spread the virus after vaccination, everyone should continue to practice COVID-19 prevention measures where appropriate. This is especially important when around people who are unvaccinated and at greater risk for severe COVID-19 illness and in crowded indoor settings, such as when using public transportation.

Get COVID-19 vaccine information and access to COVID-19 resources from Sharp HealthCare.

Get the best of Sharp Health News in your inbox

Our weekly email brings you the latest health tips, recipes and stories.