WHO Director-General Tedros Adhanom Ghebreyesus Ph.D. said on 29 June 2022, COVID-19 cases are rising in 110 countries, driven by BA.4 and BA.5 in many places, causing overall global cases to increase by 20%, and deaths have risen in three of the six WHO regions.
The SARS-CoV-2 variants BA.4 and BA.5 were first detected in South Africa in January and February 2022 and became dominant locally in May 2022. As of 12 May 2022, ECDC reclassified Omicron sub-lineages BA.4 and BA.5 from variants of interest to variants of concern. According to the European Centre for Disease Prevention and Control report, most European Union/European Economic Area (EU/EEA) countries have detected the SARS-CoV-2 variants BA.4 and BA.5, and many have seen an increase in recent weeks. In Portugal, for example, BA.5 has become the dominant SARS-CoV-2 variant, and a surge in COVID-19 cases has accompanied the increasing proportions of BA.5. The growth advantage reported for BA.4 and BA.5 suggests that these variants will become dominant throughout the EU/EEA, probably resulting in an increase in COVID-19 cases in the coming weeks. According to the sequences submitted to GISAID, the percentage of BA.4 increased from 9% to 12%, and BA.5 increased from 28% to 43%.
The increased infection is due to the ability of BA.4 and BA.5 to evade immune protection against infection induced by prior infection and/or vaccination, particularly if this has waned over time. Based on preliminary in-vitro data from preprints, BA.4 and BA.5 are antigenically distant from the ancestral virus and, compared to BA.1 and BA.2, they are less efficiently neutralized by sera from individuals vaccinated with three doses of COVID-19 vaccine (Vaxzevria or Comirnaty), or by sera from BA.1 vaccine breakthrough infections.
For persistent infection, keep testing.
Bioperfectus aims to provide our customers with high-quality and reliable total solutions of molecular diagnostics to SARS-CoV-2. We keep closely tracking the reported COVID-19 variants. After analysis and experiment, the performance of our COVID-19 detection products, including SARS-CoV-2 Real-time PCR kits and rapid antigen tests, will not be affected by BA.4 and BA.5. For more information, kindly find the Declaration Letter.
- Willett BJ, Kurshan A, Thakur N, Newman J, Manali M, Tyson G, et al. Distinct antigenic properties of the SARS-CoV-2 Omicron lineages BA.4 and BA.5. bioRxiv. 2022.05.25.493397. Available at: http://biorxiv.org/content/early/2022/05/25/2022.05.25.493397.abstract.
- Tuekprakhon A, Huo J, Nutalai R, Dijokaite-Guraliuc A, Zhou D, Ginn HM, et al. Further antibody escape by Omicron BA.4 and BA.5 from vaccine and BA.1 serum. bioRxiv. 2022.05.21.492554. Available at: http://biorxiv.org/content/early/2022/05/23/2022.05.21.492554.abstract
- Khan K, Karim F, Ganga Y, Bernstein M, Jule Z, Reedoy K, et al. Omicron sub-lineages BA.4/BA.5 escape BA.1 infection elicited neutralizing immunity. medRxiv. 2022.04.29.22274477. Available at: http://medrxiv.org/content/early/2022/05/01/2022.04.29.22274477.abstract