RESUMO
The SARS-CoV-2 Omicron variant has demonstrated enhanced transmissibility and escape of vaccine-derived immunity. While current vaccines remain effective against severe disease and death, robust evidence on vaccine effectiveness (VE) against all Omicron infections (i.e. irrespective of symptoms) remains sparse. We addressed this knowledge-gap using a community-wide serosurvey with 5,310 subjects by estimating how vaccination histories modulated risk of infection in Hong Kong (which was largely infection naive) during a large wave of Omicron epidemic during January-July 2022. We estimated that Omicron infected 45% (41-48%) of the Hong Kong population. Three and four doses of BNT162b2 or CoronaVac were effective against Omicron infection (VE of 47% (95% credible interval 34-68%) and 70% (43-99%) for three and four doses of BNT162b2 respectively; VE of 31% (1-73%) and 59% (10-99%) for three and four doses of CoronaVac respectively) seven days after vaccination, but protection waned with half-lives of 15 (3-47) weeks for BNT162b2 and 5 (1-37) weeks for CoronaVac. Our findings suggest that booster vaccination can temporarily enhance population immunity ahead of anticipated waves of infections.
RESUMO
BackgroundPatients with kidney diseases are at risk of severe complications from COVID-19, yet little is known about the effectiveness of COVID-19 vaccines in children and adolescents with kidney diseases. MethodsWe investigated the immunogenicity and safety of an accelerated, 3-dose primary series of COVID-19 vaccines among 64 pediatric chronic kidney disease patients (mean age 12.2; 32 male) with or without immunosuppression, dialysis, or kidney transplant. CoronaVac was given to those aged <5 years, 0.1ml BNT162b2 to those aged 5-11 years, and 0.3ml BNT162b2 to those aged 11-18 years. ResultsAntibody responses including S-RBD IgG (90.9-100% seropositive) and surrogate virus neutralization (geometric mean sVNT% level, 78.6-94.0%) were significantly elicited by 3 doses of any vaccine. T cell responses were also elicited. Weaker neutralization responses were observed among kidney transplant recipients and non-dialysis children receiving rituximab for glomerular diseases. Neutralization was reduced against Omicron BA.1 compared to wild-type (post-dose 3 sVNT% level; 84% vs 27.2%; p<0.0001). However, T cell response against Omicron BA.1 was preserved, which likely confer protection against severe COVID-19. Hybrid immunity was observed after vaccination in infected patients, as evidenced by higher Omicron BA.1 neutralization response among infected patients receiving 2 doses than those uninfected. Generally mild or moderate adverse reactions following vaccines were reported. ConclusionsOur findings support that an accelerated 3-dose primary series with CoronaVac and BNT162b2 is safe and immunogenic in young children and adolescents with kidney diseases. TRIAL REGISTRATIONClinicaltrials.gov NCT04800133 SIGNIFICANCE STATEMENTLittle is known about the effectiveness of COVID-19 vaccines in children and adolescents with kidney diseases. This paper describes the antibody and T cell responses of 3 doses of CoronaVac or BNT162b2, the top 2 COVID-19 vaccines distributed worldwide, by an accelerated regimen in patients with kidney diseases aged 1-18 years. Antibody and T cell responses were significantly elicited by either vaccine. Neutralization was reduced against Omicron while T cell response was preserved, which likely confer protection against severe COVID-19. Rate of severe adverse reactions was low in the study. Results confirm that accelerated 3-dose primary series with CoronaVac and BNT162b2 is safe and immunogenic in young children and adolescents with kidney diseases.
