中国疫苗提供的免疫保护较差

中国疫苗提供的免疫保护较差

中国灭活病毒疫苗
对新型冠状病毒提供最低限度的保护。

这项研究
这说明了为什么依赖中国疫苗的国家如此拼命挣扎。

这项研究来自香港
比较了 Sinovac 与 Pfizer-BioNTech 疫苗在医护人员中的疫苗免疫原性。

他们在接种疫苗之前收集了血液样本，

在第二剂之前，以及在第二剂之后 21-35 天。

They tested
for antibodies to SARS-CoV-2 using an ELISA to detect antibodies that bind to the receptor-binding domain of the spike protein.

They also tested
specifically for neutralizing antibodies with a surrogate virus neutralization assay and then a plaque reduction neutralization test with live SARS-CoV-2.

The study team
enrolled 1442 HCWs from public and private hospitals.

In HCWs who received the BNT162b2 vaccine, antibody concentrations

measured by ELISA and sVNT rose substantially after the first dose and then rose again after the second dose of vaccination.

In a subset of 12 participants for whom we also had PRNT results, after the second dose,

the geometric mean PRNT50 titer was 269 and the geometric mean PRNT90 titer was 113.

In contrast,
the healthcare workers who received the inactivated vaccine

had low antibody concentrations by ELISA and sVNT after the first dose, rising to moderate concentrations after the second dose.

In a subset of 12 participants, after the second dose,

the geometric mean PRNT50 titer
was 27 and the geometric mean PRNT90 titer was 8·4.

In summary,
the immune response (aka: immunogenicity) of the Sinovac vaccine is a fraction of what the Pfizer-BioNTech produces.

https://trialsitenews.com/chinese-vaccine-provides-inferior-immune-protection/