Press release from Pfizer-BioNTech about omicron and neutralising antibody titres after two and three vaccine doses
Press release from Pfizer-BioNTech about omicron and neutralising antibody titres after two and three vaccine doses
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The press release from Pfizer and BioNTech provides an update on the omicron variant from preliminary laboratory studies.
The press release from Pfizer and BioNTech provides an update on the omicron variant from preliminary laboratory studies.
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Expert Comments:
Prof Eleanor Riley
The press release from Pfizer provides reassuring information. Not only does a booster vaccination provide strong antibody-mediated neutralisation of Omicron but also the vast majority of the sites in the spike protein that activate T cells are conserved between Omicron and the vaccine strain. This suggests that a booster should provide high levels of protection against infection and severe disease.
However, the data also show that two doses of vaccine are not sufficient to give high neutralising activity against variant viruses. This means that whilst two doses may be enough prevent severe disease they are not sufficient to control virus transmission.
The message is clear: if we want to control virus transmission and avoid further restrictions, we need everyone who hasn’t yet done so to get vaccinated and to get their booster.
Prof Jonathan Ball
Whilst a relatively small dataset, the fact that neutralising antibody levels against the omicron variant after boosting were similar to levels seen against the original coronavirus strains after two doses of Pfizer vaccine – which we know is good at protecting from serious disease – is reassuring.
We need to understand whether these increased virus-killing antibody levels after boost plays out for all age groups, but these early signs are good. Especially as recent data from the CoV-Boost trial showed that T cells increased too after boosting
Prof Charles Bangham
These encouraging data provide strong support for the campaign to give three doses of vaccine. Emerging data from South Africa indicate that a combination of previous infection (with another variant) and vaccination also gives an enhanced antibody response. The Pfizer press release also reminds us that antibodies are not the only means by which the immune response protects against a virus: they point out that 80% of the regions of the spike protein that are recognized by cytotoxic (killer) T cells are unchanged in the omicron variant. This is likely to be a critical component of the immune response to the vaccine – and the response to previous infection – that protects against severe disease. Finally, antibodies that don’t neutralize the virus in a test tube – in vitro – also make an important contribution to antiviral protection in people.
