Publications by authors named "Sally Felle"
Objectives: Evaluation of the safety and humoral immunogenicity of ChAdOx1 nCoV-19 as a fourth dose booster in individuals who have had two initial doses of the vaccine and a third dose of BNT162b2.
Methods: COV009 is a safety follow-up study of volunteers enroled in the pivotal pre-licensure ChAdOx1 nCoV-19. In this sub-study, 149 eligible participants were given a fourth dose of ChAdOx1 nCoV-19.
Article Synopsis
- A phase 4 study in Brazil evaluated the effectiveness of fractional doses of heterologous COVID-19 vaccines in adults who had received two doses of the CoronaVac vaccine at least four months prior.
- Participants were divided into three groups, receiving either a full or half dose of ChAdOx1-S or a half dose of BNT162b2, but the study did not achieve the primary objective of an 80% seroresponse rate, with recorded rates being 34.3%, 27.1%, and 71.2% respectively.
- Despite the lower than expected seroresponse rates, all vaccine types showed robust immune responses and were well tolerated, indicating that these heterologous boosters are safe and
Article Synopsis
- Individual immune responses to the SARS-CoV-2 vaccine vary, with differences linked to specific genetic markers related to the major histocompatibility complex (MHC) class II alleles.
- A significant association was found between the HLA-DQB1*06 allele and both higher levels of antibodies against the virus's receptor-binding domain and reduced risk of breakthrough infections.
- The study suggests that variations in HLA types could influence vaccine efficacy and may inform the development of future vaccines.
Background: There are known differences in vaccine reactogenicity and immunogenicity by sex. Females have been shown to report greater reactogenicity and generate higher humoral and cellular immune responses than males following vaccination with several different vaccines. Whether this is also the case for COVID-19 vaccines is currently unknown, as COVID-19 vaccine study data disaggregated by sex are not routinely reported.
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