One vaccine dose enough for COVID-19 survivors?

NCT ID NCT04824638

First seen Apr 05, 2026 · Last updated May 15, 2026 · Updated 7 times

Summary

This study looked at whether people who had COVID-19 more than 5 months ago need only one dose of the Pfizer vaccine, while those who never had it need two doses. Researchers measured immune responses in 267 healthy adults aged 18-45 or 65+. The goal was to see if a single shot provides strong protection for those with prior infection.

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This is a summary of the original study . Summaries may miss details or leave out important information. Before applying or accepting participation, make sure you have read and understood the full study. Curemydisease.com takes no responsibility whatsoever for anything missed, misunderstood, or acted upon as a result of our summary — we know it does not capture everything.

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Contacts and locations

Locations

  • CIC 1405 , CHU Clermont-Ferrand

    Clermont-Ferrand, 63000, France

  • CIC 1427, Hopital Saint-Louis

    Paris, 75010, France

  • CIC1412, CHRU Brest

    Brest, 29609, France

  • CIC1413 , Hôtel Dieu - CHU Nantes

    Nantes, 44093, France

  • CIC1415, CHRU Tours Hôpital Bretonneau

    Tours, 37044, France

  • CIC1417, hôpital Cochin

    Paris, 75 679, France

  • CIC1430, Hôpital Henri Mondor

    Créteil, 94000, France

  • CIC1434, Nouvel Hôpital Civil - Hôpitaux Universitaires de Strasbourg

    Strasbourg, 67091, France

  • Centre de Recherche Clinique, CHU Côte de Nacre

    Caen, 14000, France

  • Service des maladies infectieuses, CHU de Caremeau

    Nîmes, 30029, France

  • URCI, Hôpital Lyon Sud

    Pierre-Bénite, 69310, France

Conditions

Explore the condition pages connected to this study.