'Cautious optimism' after initial Omicron studies; here's what we know
Early studies on the Omicron variant of coronavirus reportedly present a less grim picture than previously imagined. While the variant does evade immunity, there is not a complete loss of immunological protection, research from South Africa, Sweden, Germany, and others found. COVID-19 vaccines produced by Pfizer and BioNTech may be less effective against Omicron, but booster doses can help.
- The Omicron variant is the most heavily mutated strain detected yet and it could alter the trajectory of the pandemic.
- Governments worldwide are ramping up COVID-19 vaccinations and issuing preventive measures amid the scare.
- Preliminary evidence suggests Omicron is milder than the Delta variant.
- However, experts caution it may be too early to draw conclusions.
"We can prevent Omicron from becoming a global crisis," World Health Organization Director-General Dr. Tedros Adhanom Ghebreyesus said. The collective commitment to combat the pandemic must not change, even if the virus does, he said. "Certain features of Omicron, including its global spread and a large number of mutations, suggest it could have a major impact on the course of the pandemic," he added.
The WHO will review the findings of a recent study by Pfizer-BioNTech on how their vaccines work against Omicron, said the director of immunization and vaccines, Kate O'Brien. The Delta variant remains dominant and vaccination with existing shots continues to be a priority, she said.
The study compared neutralizing antibody levels in subjects carrying Omicron against those carrying the original strain after receiving two vaccine doses. It found a 25-fold reduction in antibody levels with Omicron, i.e., the new variant does escape immunity to some extent. Antibody levels were noted to increase with booster doses. A similar South African study on Pfizer-BioNTech vaccines reported a 41-fold drop in protection.
A German study also corroborated these findings, noting a 37-fold reduction in antibodies against Omicron compared to the Delta variant. Another study by Stockholm's Karolinska Institute, however, indicated only a slight decline in vaccine protection between Omicron and Delta strains.
The findings are preliminary and the precise amounts of immune evasion could alter, Alex Sigal—the head of research at the Africa Health Research Institute—told Bloomberg. Omicron is more resistant to antibody neutralization than the Beta strain, he said. The question as to whether existing vaccines need to be modified remains. Regardless, Pfizer has said an Omicron-targeted shot would be ready by March 2022.
According to the WHO, Omicron cases have been found in 57 countries, although no deaths have been reported. In Asia, the new variant has been detected in India, Japan, Malaysia, Singapore, Sri Lanka, South Korea, etc.