As Canada spikes in Omicron cases, a study in South Africa found that the Pfizer vaccine may not be effective at preventing infection by the variant, but against severe disease.
Scientists have been racing to uncover data about Omicron since its arrival was first flagged last month. Daily infections in South Africa have now reached 20,000 COVID-19 infections.
The real-world study is considered preliminary, but offers some evidence as public health officials prepare to deal with the spike.
The five main findings of a case study in South Africa from 15 November to 7 December were:
1. Pfizer’s protection from two doses of mRNA vaccine has been reduced to 33%, from 80% before
2. The vaccine’s ability to protect against severe illness, as measured by hospitalization, is 70%, compared with 93% during the Delta wave of infections
3. Omicron seems to have a higher risk of reinfection than previous episodes
4. Children appear to have a 20% higher risk of hospitalization with complications, but this is very early data, with a small number of cases, so careful follow-up is needed for confirmation.
5. For a clear portrait of Omicron’s impact, scientists say, it’s important to study how this variant behaves in other countries, other populations.