One vaccine against multiple coronaviruses
Chimeric spike mRNA vaccines protect against Sarbecovirus challenge in mice
Using chimeric spike designs, we demonstrate protection against challenge from SARS-CoV, SARS-CoV-2, SARS-CoV-2 B.1.351, bat CoV (Bt-CoV) RsSHC014, and a heterologous Bt-CoV WIV-1 in vulnerable aged mice. Chimeric spike mRNAs induced high levels of broadly protective neutralizing antibodies against high-risk Sarbecoviruses. In contrast, SARS-CoV-2 mRNA vaccination not only showed a marked reduction in neutralizing titers against heterologous Sarbecoviruses, but SARS-CoV and WIV-1 challenge in mice resulted in breakthrough infections.
SARS-CoV-2 mass vaccination: Urgent questions on vaccine safety that demand answers from international health agencies, regulatory authorities, governments and vaccine developers
[Preprint.] It cannot be ignored that even accounting for the number of vaccines administered, according to the US Vaccine Adverse Effect Reporting System (VAERS), the number of deaths per million vaccine doses administered has increased more than 10-fold. With few exceptions, SARS-CoV-2 vaccine trials excluded the elderly, making it impossible to identify the occurrence of post-vaccination eosinophilia and enhanced inflammation in elderly people. Studies of SARS-CoV vaccines showed that immunized elderly mice were at particularly high risk of life-threatening Th2 immunopathology. Despite this evidence and the extremely limited data on safety and efficacy of SARS-CoV-2 vaccines in the elderly, mass-vaccination campaigns have focused on this age group from the start.
SARS-CoV-2 Breakthrough Infections in Fully Vaccinated Individuals
[Preprint.] From February 10, 2021 to May 10, 2021, we performed 2,551 nucleic acid amplification tests from samples from fully vaccinated individuals, and of these, 14 represent breakthrough infections (0.55%, 95% CI: 0.30 to 0.92). In comparison, we tested 65,877 samples from unvaccinated/partially vaccinated individuals during the same time period, of which 1,482 were positive by NAAT (2.25%, 95% CI: 2.14 to 2.37).
SARS-CoV-2 R.1 lineage variants prevailed in Tokyo in March 2021
[Preprint.] Nasopharyngeal swab samples from 108 patients who visited our hospital between February and April 2021 were analyzed. The ratio of cases showing the 501N+484K mutation rapidly increased from 8% in February to 46% in March. WGS revealed that the viruses with 501N+484K mutation are R.1 lineage variants. Evidence of increased disease severity related to the R.1 variants were not found.
The SARS-CoV-2 B.1.351/V2 variant is outgrowing the B.1.1.7/V1 variant in French regions in April 2021
[Preprint.] We analyzed 36,590 variant-specific RT-PCR tests performed on samples collected between April 12 and May 7, 2021 in France to compare variant spread. Contrarily to January to March 2021, we found that the V2 variant had a significant transmission advantage over V1 in some regions (15.1 to 16.1% in Île-de-France and 16.1 to 18.8% in Hauts-de-France). This shift in transmission advantage is consistent with the immune evasion abilities of V2 and the high levels of immunization in these regions.