Effectiveness of an inactivated Covid-19 vaccine with homologous and heterologous boosters against Omicron in Brazil

Abstract The effectiveness of inactivated vaccines (VE) against symptomatic and severe COVID-19 caused by omicron is unknown. We conducted a nationwide, test-negative, case-control study to estimate VE for homologous and heterologous (BNT162b2) booster doses in adults who received two doses of CoronaVac in Brazil in the Omicron context. Analyzing 1,386,544 matched-pairs, VE against symptomatic disease was 8.6% (95% CI, 5.6–11.5) and 56.8% (95% CI, 56.3–57.3) in the period 8–59 days after receiving a homologous and heterologous booster, respectively. During the same interval, VE against severe Covid-19 was 73.6% (95% CI, 63.9–80.7) and 86.0% (95% CI, 84.5–87.4) after receiving a homologous and heterologous booster, respectively. Waning against severe Covid-19 after 120 days was only observed after a homologous booster. Heterologous booster might be preferable to individuals with completed primary series inactivated vaccine.

Effectiveness of CoronaVac, ChAdOx1 nCoV-19, BNT162b2, and Ad26.COV2.S among individuals with previous SARS-CoV-2 infection in Brazil: a test-negative, case-control study

Using national COVID-19 notification, hospitalisation, and vaccination datasets from Brazil, we did a testnegative, case-control study to assess the effectiveness of four vaccines (CoronaVac [Sinovac], ChAdOx1 nCoV-19 [AstraZeneca], Ad26.COV2.S [Janssen], and BNT162b2 [Pfizer-BioNtech]) for individuals with laboratory-confirmed previous SARS-CoV-2 infection. We matched cases with RT-PCR positive, symptomatic COVID-19 with up to ten controls with negative RT-PCR tests who presented with symptomatic illnesses, restricting both groups to tests done at least 90 days after an initial infection. We used multivariable conditional logistic regression to compare the odds of test positivity and the odds of hospitalisation or death due to COVID-19, according to vaccination status and time since first or second dose of vaccines.

COVID-19, vaccine hesitancy and child vaccination: Challenges from Brazil

In the world, the governments' policy decisions in response to COVID-19 were very different. Many countries, including in the Americas, political polarisation in health policies has been used as a tool for ideological dispute, draining out the debate around the right to social protection and health. During 2021, these strategies were used in vaccination policies. The consequences of the dissemination of misinformation about COVID-19 vaccines overflows distrust and hesitation into an entire public health project.

4 EU-funded Zika consortia met in Marseille during the International Symposium to discuss a common strategy for vaccine development

Successful technology transfer of a Zika vaccine developed by Institut Pasteur Shanghai-Chinese Academy of Sciences (IPS-CAS) to Chongqing Zhifei Biological Products Co., Ltd.

Institut Pasteur Shanghai-Chinese Academy of Sciences (IPS-CAS), a partner of the ZIKAlliance consortium, announced that it has entered into a collaborative research agreement with Chongqing Zhifei Biological Products Stock Co., Ltd. (Zhifei) for the clinical studies and commercialization of a recombinant Zika virus subunit vaccine developed by IPS-CAS.