When Second Shot Pfizer?

You should get your second shot as close to the recommended 3-week or 4-week interval as possible. However, your second dose may be given up to 6 weeks (42 days) after the first dose, if necessary. You should not get the second dose early.

What is the interval between the first and second doses of the Pfizer and Moderna COVID-19 vaccines?

* The recommended interval between the first and second dose is 21 days for Pfizer-BioNTech and 28 days for Moderna; in this study, second doses received 17–25 days (Pfizer-BioNTech) and 24–32 days (Moderna) after the first dose were included.

How long after Pfizer COVID-19 vaccine booster is it effective?

The authors explain: “In this study, we estimated effectiveness starting from day 7 after the third dose, which is similar to the period used to define full vaccination after the second dose. Our choice is supported by high concentrations of antibodies in individuals 7 days after administration of the third dose.”