One vaccine dose enough for COVID survivors? new study investigates

NCT ID NCT04824638

Completed ⭐️ VACCINE ⭐️ Sponsor: ANRS, Emerging Infectious Diseases Source: ClinicalTrials.gov ↗

First seen Jun 27, 2026 · Last updated Jun 27, 2026

Summary

This study looked at whether people who had COVID-19 more than 5 months ago need only one dose of the Pfizer mRNA vaccine, instead of the usual two. It included 267 healthy adults aged 18-45 or 65 and older, some with prior infection and some without. Researchers measured antibody levels to see if a single dose provides strong and lasting protection.

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Conditions

The condition(s) this trial relates to.

Infections infectious disease COVID-19 prevention target

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

HEALTHY IMMUNIZATION; INFECTION

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

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