EFFECTIVENESS, SAFETY AND IMMUNOGENICITY OF THE HALF DOSE OF THE VACCINE ChadOx1 nCoV-19 (AZD1222) for COVID-19

Summary

This study is clinical trial (intervention study with external comparison group) to test vaccination with reduced dose (half dose) of ChAdOx1 nCoV-19 (AZD1222), in a 2-dose schedule with an interval of 8 weeks, including all adults aged 18 to 49 years from Viana city - Espírito Santo (ES)/Brazil, on the incidence of new cases over 12 months following treatment, compared to an external group from same state and adjusted for socio-demographic and epidemiological variables.

Timeline

Start

2021-06-01

Primary completion

2022-06-01

Completion

2022-10-30

Publications

• Medeiros-Junior NF, Gouvea MDPG, Camacho LAB, Villela DAM, Lima SMB, Schwarcz WD, Azevedo AS, Neto LFP, Domingues CMAS, Fantoni RNDS, Forechi L, Ruchdeschel T, Albertino LF, Pereira M, Rizzi RB, Muniz SM, Santos HCD, de Oliveira Roza TL, Oliveira YGP, Dias LH, Miyamoto ST, Tapia KRL, Lyra DGP, Jubini JD, Burian APN, Moulaz IR, Araujo MF, Tort LFL, Oliveira ACA, Oliveira Prado R, Pereira AAS, Miranda VHS, Speziali E, Costa-Pereira C, Alves CC, Carvalho KRA, Dos Santos LM, Oliveira-Carvalho N, Oliveira G, Santos TMAFD, Figueiredo ACC, Costa-Rocha IA, Campi-Azevedo AC, Peruhype-Magalhaes V, Garcia CC, Siqueira MM, Antonelli LRDV, Coelho-Dos-Reis JGA, Teixeira-Carvalho A, Mill JG, Martins-Filho OA, Valim V. Third Booster Half Dose of ChAdOx1-nCov-19 Is Effective, Safe, and Induces Long-Duration Humoral and Cellular Immune Response to Omicron: 1-Year Follow-Up of Viana Study. Vaccines (Basel). 2025 Oct 30;13(11):1113. doi: 10.3390/vaccines13111113.

Drugs

Indications