Analysis of information sources in references of the Wikipedia article "Zoster vaccine" in English language version.
You and patients should make every effort to ensure that two doses are administered within the recommended 2–6 month interval. If more than 6 months have elapsed since the first dose, administer the second dose as soon as possible. Do not restart the vaccine series...
The need for booster doses of either Shingrix and Zostavax has not yet been determined.
The Centers for Disease Control and Prevention, which issues vaccine recommendations, says patients who wait longer than six months needn't worry, but they should get that second dose as soon as possible. Be sure not to skip it, because two doses convey the maximum immunity, more than 90%.
The need for booster doses of either Shingrix and Zostavax has not yet been determined.
The Centers for Disease Control and Prevention, which issues vaccine recommendations, says patients who wait longer than six months needn't worry, but they should get that second dose as soon as possible. Be sure not to skip it, because two doses convey the maximum immunity, more than 90%.
You and patients should make every effort to ensure that two doses are administered within the recommended 2–6 month interval. If more than 6 months have elapsed since the first dose, administer the second dose as soon as possible. Do not restart the vaccine series...