Multiple SARS-CoV-2 variants escape neutralization by vaccine-induced immunity(medrxiv.org)
medrxiv.org
Multiple SARS-CoV-2 variants escape neutralization by vaccine-induced immunity
https://www.medrxiv.org/content/10.1101/2021.02.14.21251704v2
13 コメント
Once again, this study looks exclusively at the neutralizing effects of the antibodies in sera, and is unable to account for t-cells:
>>>One important aspect of immunity not addressed by our work is cellular immunity contributed by cytotoxic lymphocytes, including T and NK cells. Even in the absence of neutralizing humoral immunity, previous studies have suggested that cellular immunity can mitigate severe or prolonged infection (Le Bert et al. 2020). In convalescent individuals, T-cell immunity would not be restricted to spike-derived epitopes, but also from other more abundant proteins such as nucleocapsid. As such, it would be reasonable to assume that T-cell-mediated immunity elicited by infection would remain largely intact for circulating variants including B.1.351. Indeed, although recent studies by Johnson & Johnson have demonstrated reduced overall efficacy in South Africa, there was substantially more protection against severe or fatal disease than for mild-to-moderate disease (Herper et al. 2021). However, with the exception of killed whole virus vaccines, all currently available vaccine designs only provide spike protein as the target immunogen, thus limiting T-cell immunity to spike epitopes. Notwithstanding, one recent study has demonstrated that mutations in spike epitopes do not impair T-cell responses despite escaping neutralizing antibodies (Skelly et al. 2021).
So... the jury is still out on if the vaccines generate a significant enough t-cell response to engender protection against a variant that may be able to elude the antibodies the vaccine confers, though it appears that the t-cell response is still durable from naturally infected individuals.
>>>One important aspect of immunity not addressed by our work is cellular immunity contributed by cytotoxic lymphocytes, including T and NK cells. Even in the absence of neutralizing humoral immunity, previous studies have suggested that cellular immunity can mitigate severe or prolonged infection (Le Bert et al. 2020). In convalescent individuals, T-cell immunity would not be restricted to spike-derived epitopes, but also from other more abundant proteins such as nucleocapsid. As such, it would be reasonable to assume that T-cell-mediated immunity elicited by infection would remain largely intact for circulating variants including B.1.351. Indeed, although recent studies by Johnson & Johnson have demonstrated reduced overall efficacy in South Africa, there was substantially more protection against severe or fatal disease than for mild-to-moderate disease (Herper et al. 2021). However, with the exception of killed whole virus vaccines, all currently available vaccine designs only provide spike protein as the target immunogen, thus limiting T-cell immunity to spike epitopes. Notwithstanding, one recent study has demonstrated that mutations in spike epitopes do not impair T-cell responses despite escaping neutralizing antibodies (Skelly et al. 2021).
So... the jury is still out on if the vaccines generate a significant enough t-cell response to engender protection against a variant that may be able to elude the antibodies the vaccine confers, though it appears that the t-cell response is still durable from naturally infected individuals.
Isn't that being a little optimistic? After all if this was good news, it wouldn't be news :-)
Fully appreciating the point: antibody response is not the only response of the immune system.
The other story on HN right now is "AstraZeneca vaccine doesn't prevent B1351 Covid in early trial" – a finding consistent with the results of this study (yes, yes, AZ vaccine != Pfizer/Moderna).
https://www.cidrap.umn.edu/news-perspective/2021/03/astrazen...
So what becomes interesting is: does the AZ vaccine not produce the same T-cell response as Pfizer/Moderna, or are these vaccines in fact broadly similar (mutants don't affect T-cells but affect antibodies). The latter wouldn't be consistent with Skelly 2021.
Fully appreciating the point: antibody response is not the only response of the immune system.
The other story on HN right now is "AstraZeneca vaccine doesn't prevent B1351 Covid in early trial" – a finding consistent with the results of this study (yes, yes, AZ vaccine != Pfizer/Moderna).
https://www.cidrap.umn.edu/news-perspective/2021/03/astrazen...
So what becomes interesting is: does the AZ vaccine not produce the same T-cell response as Pfizer/Moderna, or are these vaccines in fact broadly similar (mutants don't affect T-cells but affect antibodies). The latter wouldn't be consistent with Skelly 2021.
plutonorm(3)
https://www.sciencedirect.com/science/article/pii/S009286742...