A large real world study conducted in South Africa has found that 2 doses of the Pfizer-BioNTech COVID vaccine provides 70 percent protection against critical illness and hospitalisation from the Omicron variant.
Although the study authors called it 'very good protection', it is noticeably lower when compared to the 90 percent protection the vaccine was previously found to give against severe illness from the Delta variant.
A recent study published in the journal Lancet just a couple of months ago in October had also confirmed that the vaccine continued to elicit 90 percent protection against critical illness and hospitalisation.
The timing of the study also coincides with the spike in cases of the Omicron variant in South Africa, leading the study researchers to consider a causal link between the two.
The study was conducted by Discover Health, one of South Africa's largest private health insurance administrator, and the preliminary data was made public on Tuesday, 14 December.
What the Study Found
The study looked at 211,000 positive COVID-19 cases. Of these, 78,000 cases recorded between 15 November and 7 December are thought to be of the Omicron variant.
The study looked at breakthrough infections in those who had received the Pfizer vaccine—one of two COVID-19 vaccines being administered in South Africa (the other being Johnson & Johnson).
According to the preliminary results of the study calculated by Discovery Health, the Pfizer BioNTech vaccine was now found to provide,
33 percent protection against infection.
70 percent protection against severe illness and death.
Both figures considerably lower than its performance against other COVID variants.
Although other recent studies from South Africa and elsewhere have shown that the Omicron variant has a higher risk of breakthrough infections, this is the first study to provide some clue as to how the vaccine protection against severe illness holds up in the face of the new variant of concern.
The study also concluded that the risk of hospitalisation in those infected with COVID-19 now is 29 percent lower than at the beginning of the pandemic.
This, in spite of the rate of infections, reinfections and breakthrough infections being higher with the Omicron variant.
Moreover, the study authors also concluded that although the overall instances of COVID in kids is low, this time around, South Africa seems to have a 20 percent higher instance of COVID positive children being hospitalised with complications as compared to the first wave.
A Case for Boosters?
On a slightly optimistic note, on the whole, most infections of Omicron have resulted in just mild symptoms with patients recovering within around three days.
In spite of this, experts warn caution as we are still watching the variant's impact unfold, reiterating that it still has the potential to turn overwhelming in the future if its spread is not effectively curbed.
"The omicron-driven fourth wave has a significantly steeper trajectory of new infections relative to prior waves," Ryan Noach, Discovery Health's Chief Executive Officer was quoted as saying by the Washington Post.
"National data show an exponential increase in both new infections and test positivity rates during the first three weeks of this wave, indicating a highly transmissible variant with rapid community spread of infection."Ryan Noach, CEO, Discorvery Health as quoted as saying by the Washington Post
The findings of this study further bolsters the argument for booster shots of the COVID vaccine to make up for the waning vaccine immunity.
In fact, South Africa also approved booster doses for all adults and immunocompromised children in light of the rise in COVID cases and the Omicron variant.
(Written with inputs from the Washington Post.)