x

Science

How Quickly Do I Need a Second COVID-19 Vaccine Shot?

The first COVID-19 vaccines in the U.S. require two doses a few weeks apart. 

People should get some degree of protection within two weeks of the first shot, with the second shot bringing about the vaccine's full protection. For the vaccine by Pfizer and Germany's BioNTech, the second shot is supposed to be after three weeks. For Moderna, it's four weeks.

But how closely those guidelines should be followed has been a point of difference for the United States and the United Kingdom, which has been rolling out the Pfizer vaccine and one by Astrazeneca that requires two doses given four weeks apart.

To get more first shots into people and give them at least some degree of protection, the UK says it's OK to delay the boosters for as long as 12 weeks. But that strategy has been nixed in the U.S., where regulators say there's no science backing the approach. 

A major concern is that it's unknown how long the partial protection from one dose can last. "There is no data to demonstrate that protection after the first dose is sustained after 21 days," Pfizer said.

U.S. regulators agreed, saying too few people in the Pfizer and Moderna vaccine studies missed their scheduled boosters to have enough data to show the strategy might work.

The timing of the shots doesn't have to be exact in the U.S., though; the Centers for Disease Control and Prevention says the second shots can be given up to four days earlier or later. 

RELATED

The strong El Nino weather condition that added a bit of extra heat to already record warm global temperatures is gone.

Top Stories

Columnists

A pregnant woman was driving in the HOV lane near Dallas.

General News

NEW YORK – Meropi Kyriacou, the new Principal of The Cathedral School in Manhattan, was honored as The National Herald’s Educator of the Year.

Video

1 of 2 Abducted Louisiana Children is Found Dead in Mississippi after Their Mother is Killed

JACKSON, Miss. (AP) — A Louisiana woman was found dead in her home Thursday, and her two young daughters were abducted and found hours later in Mississippi — one dead and the other alive, police said.

ATHENS – Acknowledging disappointing results in the European Parliament elections for New Democracy, Prime Minister Kyriakos Mitsotakis said there won’t be early elections in Greece and dismissed any idea of taking New Democracy further right.

NEW YORK – This year, Leros New York is the standout team in the Premier Division of the Long Island Soccer Football League (LISFL) – and beyond.

ROME - There were multiple triumphs for Greece this week at at the European Athletics Championships in Rome.

LAUSANNE, Switzerland (AP) — The Spanish team for men's soccer at the Paris Olympics got permission Thursday from the IOC to select two players who previously played for other countries.

Enter your email address to subscribe

Provide your email address to subscribe. For e.g. [email protected]

You may unsubscribe at any time using the link in our newsletter.