Weekly epidemiological update on COVID-19 - 14 December 2022
Edition 122
14 December 2022
| Emergency Situational Updates
Overview
Globally, the number of new weekly cases remained stable (+2%) during the week of 5 to 11 December 2022 as compared to the previous week, with over 3.3 million new cases reported . The number of new weekly deaths increased by over 10% as compared to the previous week, with over 9700 new fatalities reported. As of 11 December 2022, over 645 million confirmed cases and over 6.6 million deaths have been reported globally.
In this edition, we include:
- The COVID-19 epidemiological update at the global and regional levels.
- An update on the circulating SARS-CoV-2 variants of concern (VOCs) and Omicron subvariants under monitoring, in addition to, impact of vaccines.
- An update on hospitalizations and ICU admissions related to COVID-19.
SARS-CoV-2 variants of concern and Omicron subvariants under monitoring
Geographic spread and prevalence
Globally, from 24 October to 20 November 2022,i 204 995 SARS-CoV-2 sequences were shared through GISAID.
Among these, 204 042 sequences were the Omicron variant of concern (VOC), representing 99.5% of sequences reported globally.
BA.5 descendent lineages remain predominant, with a prevalence of 73.7% as of epidemiological week 46 (14 to 20November 2022), followed by BA.2 descendent lineages, with a prevalence of 10.4%.
BA.4 descendent lineages havedeclined in prevalence, accounting for 2.0% of sequences within the same reporting period.
XBB and descendent lineages account for 3.9%, a trend that is rising.
Unassigned sequences (presumed to be Omicron subvariants) account for 9.9% of sequences submitted to GISAID in week 46.
The evolution of Omicron descendent variants continues to show genetic diversification and has resulted in more than 540 descendent lineages, and more than 61 recombinants. However, only some of these descendent lineages continue to increase in prevalence, while others remain at only a few sequence detections. Among the more relevant variant lineages, specific substitutions are accumulating, a genetic pattern referred to as convergent evolution.
Five Omicron subvariants are under monitoring (VUM) due to relevant genetic variation, rise in prevalence, and/or an observed and continued impact on case incidence in more than one country.
As of week 46, these five pooled
Omicron subvariants under monitoring have replaced previous BA.5 descendent lineages and account for 63.5% of prevalence at a global level. The replacement pattern of these subvariants points to a potential role of specific mutations in growth advantage, probably by immune escape properties (Figure 5).
Omicron subvariants under monitoring have replaced previous BA.5 descendent lineages and account for 63.5% of prevalence at a global level. The replacement pattern of these subvariants points to a potential role of specific mutations in growth advantage, probably by immune escape properties (Figure 5).
• BA.2.75* carries the substitutions S:D339H, S:G446S, S:N460K and the S:Q493R reversion. Two notable BA.2.75 variants with additional mutations of interest within the Spike protein are BA.2.75.2 (BA.2.75 + S:R346T, S:F486S, and S:D1199) and CH.1.1 (BA.2.75 + S:R346T, S:K444T, S:L452R, and S:F486S).
BA.2.75 was first identified on 31 December 2021 and began to spread in a few countries in the South-East Asia Region. Since its emergence, BA.2.75 has been reported from 85 countries. The five countries reporting the highest prevalence of BA.2.75 are
Thailand (53.8%), Australia (25.1%), Malaysia (22.5%), China (18.8%), and New Zealand (16.3%).
Thailand (53.8%), Australia (25.1%), Malaysia (22.5%), China (18.8%), and New Zealand (16.3%).
BA.2.75* became rapidly dominant in India and in Bangladesh; but was then replaced by XBB* without an indication of a significant rise in reported case incidence. From currently available evidence, BA.2.75* has not shown a significantly different
phenotype as compared to other Omicron variants in countries where it has become widespread.
phenotype as compared to other Omicron variants in countries where it has become widespread.
• BA.5 with one or several of the 5 mutations S:R346X, S:K444X, S:V445X, S:N450X, and/or S:N460X is monitored as these mutations have been associated with or are suspected to have an important functional role to the virus (e.g., resistance to neutralization, increased transmissibility). This class of variants has risen rapidly and is detected
in 119 countries, accounting for a global prevalence of 15.0%. The five countries reporting the highest prevalence of BA.5 are South Africa (75.4%), Costa Rica (70.9%), Peru (53.5%), Mexico (49.8%), and Brazil (42.4%).
• BQ.1* is a BA.5 descendent lineage with additional substitutions S:K444T and S:N460K. The BQ.1 descendent lineage with the highest prevalence is BQ.1.1, and carries the additional mutation S:R346T.
BQ.1* is one of the fastest growing variants and has spread to 90 countries, with a prevalence of 33.9% as of week 46. The five countries reporting the highest prevalence of BQ.1* variants are Ecuador (65.5%), Portugal (56.7%), Spain (54.1%), France (48.7%), and Colombia (46.8%).
This reporting period was used to account for an average turnaround time of 21 days from sample collection to sequence submission to GISAID.
Includes all descendent lineages.
Includes all descendent lineages.
• XBB* is a recombinant of the BA.2.10.1 and BA.2.75 sublineages, first reported on 13 August 2022. Relevant mutations in this recombinant are S:G339H, S:R346T, S:L368I, S:V445P, S:G446S, S:N460K, S:F486S and S:F490S.
As of week 46 , XBB* has a global prevalence of 3.8% and it has been detected in 70 countries. The five countries with the highest prevalence of XBB* are India (62.5%), the Dominican Republic (48.2%), Singapore (47.3%),
Malaysia (40.9%), and Indonesia (29.3%).
• BA.2.30.2 carries the mutations S:K444R, S:N450D, S:L452M, S:N460K and S:E484R. As of week 46, BA.2.30.2 has a global prevalence of 0.3%. Countries with the highest prevalence are Iceland (4%), Slovenia (2%), Australia (1.1), Colombia (0.9%) and the Republic of Korea (0.6%).
As presented above, Omicron subvariants under monitoring (VUM) share several relevant mutations but show different patterns of geographic spread. BA.2.75 and XBB emerged and increased in prevalence mainly in countries in the South-East Asia and Western Pacific regions. Both variants are rising slowly in prevalence, but current data do not
suggest a consistent association with an increase in new infections. Co-circulation of BA.2.75 and XBB occurs in multiple countries.
BQ.1 and BA.5 + 5 mutations have emerged, risen in prevalence, and spread to many countries rapidly. Whether the increased immune escape capacity of this new series of Omicron descendent variants is sufficient to drive new infection waves appears to depend on the regional immune landscape, the size and timing of previous
Omicron waves, and the COVID-19 vaccination coverage. While further studies are needed, the current data do not suggest that there are substantial differences in disease severity for BA.2.75, BA.5 + 5 mutations, BQ.1, and XBB.
Omicron waves, and the COVID-19 vaccination coverage. While further studies are needed, the current data do not suggest that there are substantial differences in disease severity for BA.2.75, BA.5 + 5 mutations, BQ.1, and XBB.
Figure 5. Panel A and B: The number and percentage of SARS-CoV-2 sequences, from 1 June to 12 December 2022
(Ps. tässä linkissä on selkeitä kuvia varianttien dominanssista viimeksi kuluneena puolena vuotena. Kaikki ovat kuitenkin omikroneita. Eli ei ole tarvittu uutta kreikkalaista erisnimeä).
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