Mary Wilson
Well-known member
Published 30 November 2022
doi: https://doi.org/10.1136/bmj-2022-073070
Juan Manuel Castelli, infectious disease specialist1, Analia Rearte
, professor, epidemiologist1 2, Santiago Olszevicki, data scientist1, Carla Voto, infectious disease specialist1, María Del Valle Juarez, epidemiologist1, Martina Pesce, epidemiologist1, Agustina Natalia Iovane, epidemiologist1, Mercedes Paz, epidemiologist1, María Eugenia Chaparro, epidemiologist1, Maria Pia Buyayisqui, epidemiologist1, María Belén Markiewicz, epidemiologist1, Mariana Landoni, information systems engineer1 3,
Carlos María Giovacchini, epidemiologist1 3, Carla Vizzotti, minister of health1
Abstract
Objective To estimate the effectiveness of a two dose vaccine schedule (mRNA-1273, BNT162b2, and BBIBP-CorV) against SARS-CoV-2 infection and covid-19 related death and short term waning of immunity in children (3-11 years old) and adolescents (12-17 years old) during periods of delta and omicron variant predominance in Argentina.
Design Test negative, case-control study.
Setting Database of the National Surveillance System and the Nominalized Federal Vaccination Registry of Argentina.
Participants 844 460 children and adolescents without previous SARS-CoV-2 infection eligible to receive primary vaccination schedule who were tested for SARS-CoV-2 by polymerase chain reaction or rapid antigen test from September 2021 to April 2022. After matching with their corresponding controls, 139 321 (60.3%) of 231 181 cases remained for analysis.
Exposures Two dose mRNA-1273, BNT162b2, and BBIBP-CorV vaccination schedule.
Main outcome measures SARS-CoV-2 infection and covid-19 related death. Conditional logistic regression was used to estimate the odds of SARS-CoV-2 infection among two dose vaccinated and unvaccinated participants. Vaccine effectiveness was estimated as (1–odds ratio)×100%.
Results Estimated vaccine effectiveness against SARS-CoV-2 infection was 61.2% (95% confidence interval 56.4% to 65.5%) in children and 66.8% (63.9% to 69.5%) in adolescents during the delta dominant period and 15.9% (13.2% to 18.6%) and 26.0% (23.2% to 28.8%), respectively, when omicron was dominant. Vaccine effectiveness declined over time, especially during the omicron period, from 37.6% (34.2% to 40.8%) at 15-30 days after vaccination to 2.0% (1.8% to 5.6%) after ≥60 days in children and from 55.8% (52.4% to 59.0%) to 12.4% (8.6% to 16.1%) in adolescents.
Vaccine effectiveness against death related to SARS-CoV-2 infection during omicron predominance was 66.9% (6.4% to 89.8%) in children and 97.6% (81.0% to 99.7%) in adolescents.
Conclusions Vaccine effectiveness in preventing mortality remained high in children and adolescents regardless of the circulating variant. Vaccine effectiveness in preventing SARS-CoV-2 infection in the short term after vaccination was lower during omicron predominance and decreasing sharply over time.
Trial registration National Registry of Health Research IS003720.
https://www.bmj.com/content/379/bmj-2022-073070
doi: https://doi.org/10.1136/bmj-2022-073070
Juan Manuel Castelli, infectious disease specialist1, Analia Rearte
, professor, epidemiologist1 2, Santiago Olszevicki, data scientist1, Carla Voto, infectious disease specialist1, María Del Valle Juarez, epidemiologist1, Martina Pesce, epidemiologist1, Agustina Natalia Iovane, epidemiologist1, Mercedes Paz, epidemiologist1, María Eugenia Chaparro, epidemiologist1, Maria Pia Buyayisqui, epidemiologist1, María Belén Markiewicz, epidemiologist1, Mariana Landoni, information systems engineer1 3, Carlos María Giovacchini, epidemiologist1 3, Carla Vizzotti, minister of health1
Abstract
Objective To estimate the effectiveness of a two dose vaccine schedule (mRNA-1273, BNT162b2, and BBIBP-CorV) against SARS-CoV-2 infection and covid-19 related death and short term waning of immunity in children (3-11 years old) and adolescents (12-17 years old) during periods of delta and omicron variant predominance in Argentina.
Design Test negative, case-control study.
Setting Database of the National Surveillance System and the Nominalized Federal Vaccination Registry of Argentina.
Participants 844 460 children and adolescents without previous SARS-CoV-2 infection eligible to receive primary vaccination schedule who were tested for SARS-CoV-2 by polymerase chain reaction or rapid antigen test from September 2021 to April 2022. After matching with their corresponding controls, 139 321 (60.3%) of 231 181 cases remained for analysis.
Exposures Two dose mRNA-1273, BNT162b2, and BBIBP-CorV vaccination schedule.
Main outcome measures SARS-CoV-2 infection and covid-19 related death. Conditional logistic regression was used to estimate the odds of SARS-CoV-2 infection among two dose vaccinated and unvaccinated participants. Vaccine effectiveness was estimated as (1–odds ratio)×100%.
Results Estimated vaccine effectiveness against SARS-CoV-2 infection was 61.2% (95% confidence interval 56.4% to 65.5%) in children and 66.8% (63.9% to 69.5%) in adolescents during the delta dominant period and 15.9% (13.2% to 18.6%) and 26.0% (23.2% to 28.8%), respectively, when omicron was dominant. Vaccine effectiveness declined over time, especially during the omicron period, from 37.6% (34.2% to 40.8%) at 15-30 days after vaccination to 2.0% (1.8% to 5.6%) after ≥60 days in children and from 55.8% (52.4% to 59.0%) to 12.4% (8.6% to 16.1%) in adolescents.
Vaccine effectiveness against death related to SARS-CoV-2 infection during omicron predominance was 66.9% (6.4% to 89.8%) in children and 97.6% (81.0% to 99.7%) in adolescents.
Conclusions Vaccine effectiveness in preventing mortality remained high in children and adolescents regardless of the circulating variant. Vaccine effectiveness in preventing SARS-CoV-2 infection in the short term after vaccination was lower during omicron predominance and decreasing sharply over time.
Trial registration National Registry of Health Research IS003720.
https://www.bmj.com/content/379/bmj-2022-073070