en.pdf?__blob=publicationFile. 38. Ministère des Solidarités et de la Santé. Première détection d’un cas de contamination au variant VOC.
271 KB – 26 Pages
PAGE – 1 ============
Suggested citation: European Centre for Disease Prevention and Control. Risk related to spread of new SARS – CoV – 2 variants of concern in the EU/EEA 29 December 2020 . ECDC: Stockholm; 20 20 . © European Centre for Disease Prevention and Control, Stockholm, 20 20 RAPID RISK ASSE SS MENT R isk related to spread of new SARS – CoV – 2 variants of concern in the EU/EEA 29 December 2020 Summary Viruses constantly change through mutation , and so the emergence of new variants is an expected occurrence and not in itself a cause for concern ; SARS – CoV – 2 is no exception. A diversification of SARS – CoV – 2 due to evolution and adaptation processes has been observed globally. While most emerging mutations will not have a significant impact on the spread o f the virus, some mutations or combinations of mutations may provide the virus with a selective advantage, such as increased transmissibility or the ability to evade the host immune response. In such case s , these variants could increase the risk to human health and are considered to be variants of concern . New variants of c urrent c oncern The United Kingdom (UK) has faced a rapid increase in COVID – 19 case rates in the South – East , the East and the London area , which is associated with the emergence of a new SARS – CoV – 2 variant , VOC 202012/01. As of 26 December 2020 , m ore than 3 000 cases of this new variant , confirmed by genome sequencing , ha ve been reported from the UK . An increasing proportion of cases in the South E ast, the East and the London area are due to this variant, but cases have also been identified in other parts of the UK. Although it was first reported in early December, the initial cases were retrospectively identified as having emerged in late September. Preliminary analys e s indicate that the new variant has increased transmissibility compared to previously circulating variants , but n o increase in infection severity has so far been identified . Since 26 December , a f ew VOC 202012/01 cases have al so been reported in other EU/EEA countries (Belgium, Denmark, Finland, France, Germany, Iceland , Ireland, Italy, the Netherlands , Norway, Portugal, Spain and Sweden ) and globally ( A us tralia, Canada, Hong Kong SAR , India, Israel, Japan, Jordan, Lebanon, South Korea, Switzerland, Singapore). In addition to VOC 202012/01 , South Africa has reported another SARS – CoV – 2 variant , designated as 501 .V2 , which is also of potential concern . This variant was first observed in samples from October, and since then more than 300 cases with the 501.V2 variant have been confirmed by whole genome sequencing (WGS) in South Africa , where it is now the dominant form of the virus . Preliminary results indicate that this variant may have an increased transmissibility . However, like the VOC 202012/01 , at this stage there is no evidence that 501.V2 is associated with higher severity of infection . On 22 December 2020, two geographically separate cases of this new variant 501.V2 were detected in the UK . Both are contacts of sympt omatic individuals returning from travel to South Africa . On 28 December 2020, one additional case of this new variant was detected in Finland in a returning traveller from South Africa . Risks a ssociated with new variants of current c oncern ECDC assesses that the probability of SARS – CoV – 2 VOC 202012/01 and 501.V2 being introduced and further spread in the EU/EEA is currently high . Although there is no information that infection s with these strains are
PAGE – 2 ============
RAPID RISK ASSESSMEN T Risk related to spread of new SARS – CoV – 2 variants of concern in the EU/EEA 29 December 20 20 2 more severe , due to increased transmissibilit y th e impact of COVID – 19 disease in terms of hospitalisations and deaths is assessed as high , particularly for those in older age groups or with co – morbidities . The overall risk associated with the introduction and further spread of SARS – CoV – 2 VOC 202012/01 and 501.V2 is therefore assessed as high . The probability of increased circulation of any SARS – CoV – 2 strains and this placing grea ter pressure on health systems in the coming weeks is considered to be high due to the festive season and, higher still, in countries where the new variants are established. T he impact of this increased pressure on health systems i s considered to be high even if current public health measures are maintained . Therefore, the overall risk of an increased impact on health systems in the coming weeks is assessed as high . Maintain ing and s trengthen ing non – pharmaceutical i nterventions Member States are recommended to c ontinue to advise th eir citizens o f the need for non – pharmaceutical interventions in accord ance with their local epidemiological situation and national policies and , in particular , to consider guidance on the avoidance of non – essential travel and social activities. Options for delaying the introduction of variants of concern The options available f o r delay in g the introduction and further spread of a new variant of concern are : to p erform targeted and representative sequencing of community cases to detect early and monitor the incidence of the variant; to i ncrease follow – up and testing of people with an epidemiological link to areas with significantly higher incidence of the variant and to sequenc e samples from such cases; to e nhance targeted contact tracing and isolation of suspected and confirmed cases of the variant; to a lert people coming from areas with significantly higher incidence of the variant to the need to comply with quarantine , as well as getting test ed and self – isolatin g if they develop symptoms ; to recommend a void ing all non – essential travel , in particular to areas with a significantly higher incidence of the variant. Although in the short – to – medium term the roll – out of vaccination s will probably contribute to the response , these immediate measures are essential until such time as doses are available in sufficient number s and have been shown to have a mitigating effect . Increased detection and c haracterisation Member States should c ontinue to monitor for abrupt changes in rates of transmission or disease severity as part of the process of ide ntifying and assessing the impact of variants. Data analysis and assessment of the local, regional and national situation should be performed to identify areas with rapidly changing epidemiology. National public health authorities should notify cases of th e new variant , as well as any other new SARS – CoV – 2 variants of potential concern , through the Early Warning and Response System (EWRS) and The European Surveillance System (TESSy) for case – based surveillance and aggregate reporting, which has been adapted for this purpose. In order to be able to detect introductions of known variants , as well as emergence of new variants of concern, Member States need to perform timely genome sequencing of a significant and representative selection of isolates . The UK has d emonstrated that their sequencing programme is able to detect emerging variants. Ideally, Member States should aim for a similar timeliness and fraction of samples sequenced, although this will depend on the availab ility of resource s . If representative seq uencing on a similar scale to that carried out by the UK is not feasible, samples could be select ed where the involvement of a variant of concern is suspected . Event background Viruses constantly change through mutation , making the emergence of new variants an expected occurrence and not in itself a cause for concern ; SARS – CoV – 2 is no exception. In recent months, a diversification of SARS – CoV – 2 due to evolution and adaptation processes has been observed globally. While most emerging mutations will n ot provide a selective advantage to the virus, some mutations or combinations of mutations may provide the virus with such an advantage . Examples of this could be greater transmissibility due to an increase in receptor binding or the ability to evade the h ost immune response by altering the surface structures recognised by antibodies. In such case s , these variants are of concern and could be a risk to human health. This risk assessment presents the latest available information on the recent emergence of two variant s of potential concern, VOC 202012/01 discovered in the United Kingdom ( UK ) and another variant , 501.V2 identified in South Africa. It also assess es the risk of these variants of concern being introduced and spread in the EU/EEA , as well as the inc reased impact this w ould have on health systems in the coming weeks.
PAGE – 3 ============
RAPID RISK ASSESSMEN T Risk related to spread of new SARS – CoV – 2 variants of concern in the EU/EEA 29 December 20 20 3 Variant of Concern ( VOC ) 202012/01, United Kingdom Over the last few weeks, the UK has faced a rapid increase in COVID – 19 case rates ( Figure 1 and 2 and Figure A 1 in the Annex ). The s even – day case rate has rapidly increas ed from 162 cases per 100 000 pop ulation in week 49 , to 227 during week 50 /2020 (39% increase) and 344 during week 51 / 2020 ( 51 % increase) . Figure 1 . Seven – day COVID – 19 case rates per 100 000 population in the United Kingdom, by specimen date , as of 2 5 December 2020 Note : The rate represents individuals with at least one positive COVID – 19 test result per 100 000 population in the rolling seven – day period ending on the dates shown. The latest data point available is 2 5 December 2020 . Source: D ata adapted from P ublic H ealth E ngland (PHE) data porta l [1] . This increase in the weekly rate per 100 000 population is currently more pronounced in thre e regions: London, the South East and the East of England ( see F igure 2 below ) .
PAGE – 4 ============
RAPID RISK ASSESSMEN T Risk related to spread of new SARS – CoV – 2 variants of concern in the EU/EEA 29 December 20 20 4 Figure 2 . Subnational seven – day rolling rates of new COVID – 19 cases per 100 000 population in the UK , as of 21 December 2020 Source: Coronavirus (COVID – 19) in the UK [2] accessed on 27 December 2020. UTLA rate is the Upper Tier Local Authorities rate. Genomic a nalysis of viral seque nce data identified a large proportion of sequenced cases in the South East, the East and the London regions belong ing to a new single phylogenetic cluster [3] . The rapid increase in COVID – 19 cases overall was temporally associated with the emergence of a new variant in this area in November 2020. This variant is referred to as SARS – C o V – 2 V OC 202012/01 (Variant of C oncern , year 2020, month 12, variant 01 , previously designated VUI, Variant under Investigation ). The first instance of VOC 202012/01 was retrospectively identified in a case from 20 September 2020 in the UK [4] . T he number of VOC 202012/01 cases confirmed by sequencing has also increase d , indicat ing that it is present in other regions across England , but currently at much lower levels than in the south east of the country , and also that it i s presen t in Wales (Figure 3 ).
PAGE – 5 ============
RAPID RISK ASSESSMEN T Risk related to spread of new SARS – CoV – 2 variants of concern in the EU/EEA 29 December 20 20 5 Figure 3 . VOC 202012/01 cases confirmed by sequencing, case distribution in the UK , as of 25 December 2020 Source: https://beta.microreact.org/project/vVnFfZG7o3qYUJ6bnDs3Jo – cog – uk – 2020 – 12 – 20 – sars – cov – 2 – in – the – uk [5] Th is increase in case incidence with in the community is also visible in the new hospital admissions rolling rate in the UK ( England and Wales) ( F igure 4 ).
PAGE – 6 ============
RAPID RISK ASSESSMEN T Risk related to spread of new SARS – CoV – 2 variants of concern in the EU/EEA 29 December 20 20 6 Figure 4 . Seven – day COVID – 19 new hospital admissions rates per 100 000 population by nation and specimen date , as of 2 7 December 2020 , United Kingdom Note: The rate represents COVID – 19 patients admitted to hospital per 100 000 population in the rolling seven – day period ending on the dates shown. The latest common data point s available are for 20 December 2020 . Data adapted from PHE data portal [1] . As of 26 December 2020 , the UK reported the d aily number of COVID – 19 patients admitted to hospital as 2 143 (based on the latest available data , which are for 20 December 2020). This represent s an increase of around 200 daily admission s (or 10%) compared to the week before ( on 14 December 2020 the n umber of daily admission s 1 935) [1] . T he overall proportion of VOC 202012/01 among all uploaded virus sequ ences from the UK to the GISAID database has increased substantially, particularly as of week 48/2020 (Figure 5 ). These sequences are , however , derived from community – based sampling and are not geographically representative or representative of hospitalise d cases. Figure 5 . Fraction of UK SARS – CoV – 2 sequences classified as VOC 202012/01 per week, and total sequences per week from the UK, published in GISAID EpiCoV u p to 2 7 December 2020 Source: GISAID EpiCov database. Weeks 51 and 52 are omitted due to very few sequences being available for those weeks ( 252 and 0 respectively). Case n umbers with the variant virus have also been reported from other countries in the EU/EEA and globally (Table 1). Table 1 . Places reporting VOC 202012/01 cases, as of 2 9 December 2020
PAGE – 8 ============
RAPID RISK ASSESSMEN T Risk related to spread of new SARS – CoV – 2 variants of concern in the EU/EEA 29 December 20 20 8 On 22 December, the European Commission adopted a Recommendation on a coordinated approach to travel and transport in response to the SARS – C o V – 2 variant observed in the UK [44] . The aim of the Commission Recommendation is to have a coordinated approach to travel a nd transport in response to the SARS – C o V – 2 variant observed in the UK to ensure free movement during the pandemic , while discouraging all non – essential travel to limit the further spread of the new variants [45] . Variant 501.V2, South Africa As of 19 December 2020, a total of 921 922 confirmed COVID – 19 cases, including 24 691 deaths, had been reported in South Africa [46] . The country is in its second SARS – CoV – 2 epidemic wave (Figure 6 ) [46,47] . On 18 December 2020, the South African government reported the emergence and rapid increase of a new variant designated 501.V2 [48] . The new variant was detected by the Kwazulu – Natal Research Innovation and Sequencing Platform (KR ISP), through routine genomic surveillance of SARS – CoV – 2 from samples collected from over 50 different health facilities in Eastern Cape, Western Cape and KwaZulu – Natal. It has multiple changes in the spike protein, including amino – acid modification N501Y which is also present in VOC 202012/01 [49] . P hylogenetic analysis of 2 589 SARS – CoV – 2 whole genomes from South Africa collected between 5 March and 25 November 2020 identified 190 sequences of the variant from samples collected between 15 October and 25 November 2020 . This analysis indicate s that th e variant emerged in early August in Nelson Mandela Bay , located on the coast of the Eastern Cape Province. By early November, it was the dominant variant in the Eastern Cape and Western Cape Provinces [50] . Preliminary results indicate that th is variant is associated with a higher viral load and faster spread which may be related to higher transmissibility . No evidence is available yet on whether the infection severity is different [51] . T he variant emerged in South Africa during the summer season, despite a previously – observed decrease in the circulation of the virus during the summertime in other parts of the world ( e.g. Europe ) . South Africa ha s sequenced and published the genomes for 912 samples collected between 1 September and 25 December 2020, with an a verage delay of 38 days from sampling to publication. So far more than 300 cases with the variant have been confirmed in South Africa [52] . According to analysis performed by KRISP, the variant accounted for almo st all cases analysed by genome sequencing in mid – November 2020 [51] . On 22 December 2020, two geographically separate cases of this new variant were detected in the UK [53] . Both are contacts of symptomatic individuals returning from South Africa. On 28 December 2020, one case of this new variant was detected in Finland in a returning traveller from South A frica [30] . Figure 6 . Epidemic curve of confirmed COVID – 19 cases by day ( seven – day moving average), South Africa Source: National I nstitute for Communicable Diseases of South Africa – accessed on 25 December 2020.
PAGE – 9 ============
RAPID RISK ASSESSMEN T Risk related to spread of new SARS – CoV – 2 variants of concern in the EU/EEA 29 December 20 20 9 Epidemiological situation in the EU/EEA and the UK Detailed epidemiological information on laboratory – confirmed cases reported to The European Surveillance System (TESSy) is published in COVID – 19 surveillance report and the overview of the epidemiological situation of the COVID – 19 pandemic by country is also published in – 19 country overview . Overall s ituation In ECDC surveillance report , b y the end of week 51 (ending Sunday 20 December 2020), most countries ha d been seeing a stabilisation or reduction in test positivity and hospital or ICU admissions and/or occupancy due to COVID – 19. However, absolute values of these indicators remain high, even where they are stable or decreasing, suggesting that transmission is still widespread (Figure A2, Annex) . Trends in reported cases and testing For week 51 , increases in case notification rates were observed in 14 countries (Cyprus, Czechia, Denmark, Estonia, France, Germany, Ireland, Latvia, Lithuania, the Netherlands, Slovakia, Spain, Sweden and the UK ) . C ase rates among older age groups continued to increase in 12 countries . Among 24 countri es in which weekly t est positivity was high (at least 3%) , seven countries (Estonia, Ireland, Latvia, Lithuania, the Netherlands, Romania and the UK) observed an increase in test positivity , while it remained stable or had decreased in 17 countries (Austria, Belgium, Bulgaria, Croatia, Cyprus, Czechia, France, Germany, Greece, Hungary, Italy, Luxembourg, Poland, Portugal, Slovakia, Slovenia and Sweden) [54] . Hospitalisation and ICU For week 51, h ospital and/or ICU occupancy and/or new admissions due to COVID – 19 were high (at least 25% of the peak level during the pandemic) or had increased compared with the previous week in 30 countries (Austria, Belgium, Bulgaria, Croatia, C yprus, Czechia, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta , the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden and the UK [54] . Mortality Among 29 countries with high 14 – day COVID – 19 death rates (at least 10 per million), increases were observed in ten (Croatia, Denmark, Estonia, Finland, Germany, Latvia, Lithuania, the Netherlands , Slovakia and United Kingdom ) . For week 52/2020, all – cause excess mortality data from EU/EEA countries and the UK reported to the Eu r oMoMo network identified a recent substantial increase in mortality , mainly affect ing those aged 45 years and above [55] . Disease background For additional information on the latest scientific evidence relating to COVID – 19, SARS – CoV – 2, virus transmission, diagnostic testing, infection, clinical characteristics, risk factors and risk groups, immunity, and vaccines and treatment please visit ECDC website: https://www.ecdc.europa.eu/en/covid – 19/latest – evidence . Em ergence of SARS – CoV – 2 variant viruses Many thousands of variants of SARS – CoV – 2 are circulating , and more will emerg e over time , most of which will probably h ave no effect on transmission or disease characteristics. T able 2 summarises selected variants that are , or have been , under inve stigation (although it is not a comprehensive list of all SARS – CoV – 2 variants investigated ) .
PAGE – 10 ============
RAPID RISK ASSESSMEN T Risk related to spread of new SARS – CoV – 2 variants of concern in the EU/EEA 29 December 20 20 10 Table 2 . Selected SARS – CoV – 2 variants Variant Definition (amino acid changes) Potential public health impact of variant Geographic al spread References VOC 202012/01 S: del 69 – 70 , del 144, N501Y , A570D, P681H, T716I, S982A, D1118H Report of increased transmissibility from the UK. Prevalent in parts of the UK, cases increasingly detected in other countries. [56] 501.V2 S: D80A, D215G, E484K, N501Y and A701V . Report of increased transmissibility from South Africa . Domina nt in South Africa, two cases recently detected in the UK. [50,51,57] Danish mink variant S: del 69 – 70 , Y453F Transmission from mink to humans and community spread confirmed, no changes in transmissibility reported. Prevalent in Denmark. Not detected elsewhere. [58] Danish mink cluster 5 S: del 69 – 70 , Y453F, I692V, M1229I Preliminary report of moderate reduction of neutralisation by convalescent sera. Denmark, not observed since September 2020. [58] Various variants with s pike amino acid change N439K S: N439K , often with del 69 – 70 Reports of minor reduction of neutralisation by convalescent sera. Common in Czechia, Denmark, Ireland, found in lower proportions in many countries . [59 – 62] Nextstrain cluster 20A.EU1 S: A222V Rapid increase in Spain and then the rest of the EU/EEA at the start of the second wave, probably due to random events and travel patterns. First observed in Spain, the most common variant in the EU/EEA . [60] Nextstrain cluster 20A.EU2 S: S477N N: A376T Rapid increase in France at the start of the second wave, probably due to founder effects. First observed in France, prevalent also in Belgium, Cz echia, Denmark, Hungary, the Netherlands, Switzerland . [60] D614G S: D614G Rapid increase during the early stages of the pandemic in the EU/EEA and then worldwide, probably due to a mix of founder effects and increased transmissibility. Worldwide. All other variants described here are descendant from this one. [63 – 66] P roperties of VOC 202012/01 VOC 202012/01 is defined by multiple spike protein changes (deletion 69 – 70, deletion 144, N501Y, A570D, D614G, P681H, T716I, S982A, D1118H) as well as by mutations in other genomic regions [67] . One of the changes (N501Y) is located within the receptor binding domain (RBD) . The variant belongs to Nextstrain clade 2 0B [68,69] , GISAID clade GR [4,70] , lineage B.1.1.7 [71,72] . Laboratory findings Preliminary findings show that there may be an association between infection with the variant and increased viral load. The UK New and Emerging Respiratory Virus Threats Advisory Group ( NERVTAG ) reports that there is a decrease in RT – PCR threshold cycle (Ct) value by around two for th is variant compared to other variants, corresponding to an increased viral load by a factor of around four [73] . This evidence is also supported by the number of unique sequencing reads , providin g an estimate in increased viral load by around a factor of three [74] , though such estimates tend to be less reliable than estimates from RT – PCR. Increased viral load in respiratory samples is likely to be associated with increased shedding of virus and incre ased transmissibility , but this remains to be confirmed . There is some evidence indicat ing that the amino acid change N501Y is associated with increased ACE2 receptor binding strength. A study screened all possible spike protein RBD substitutions using a yeast – surface – display platform, finding an increased binding strength measured as log 10 increase in spike – ACE2 complex dissociation constant of 0.24 [75] . This was the third highest increase measured in the study , with only Y453F and N501F providing larger increases. N o clear relationship has been established between ACE2 binding and increased transmissibility, but it is plausible that such a relationship exists.
PAGE – 11 ============
RAPID RISK ASSESSMEN T Risk related to spread of new SARS – CoV – 2 variants of concern in the EU/EEA 29 December 20 20 11 Impact on diagnostic assays The S – gene deletion at genomic positions 217 65 – 21770 , corresponding to residues 69 – 70 in the spike protein in variant VOC 202012/01 and other variants carrying this mutation, such as mink – related variants from Denmark, may cause some RT – PCR assays targeting the S – gene to produce a negative result (S – gene drop – out). The tri – target (ORF1ab, N, S) COVID – 19 TaqPath assay from Thermo Fischer has been reported by the UK to have S – gene dropout for this deletion. The S – gene drop – out is unlikely to cause an overall false – negative result for SARS – CoV – 2 as the S – gene is generally not used by itself for detection of the virus . The S – gene drop – out can be used to s creen for VOC 202012/01 and , in settings with high prevalence of the variant with little or no co – circulation of other variants that cause S – gene drop – ou t, it can be used as a proxy measure of the incidence of the variant. Sequencing of the S – gene as a minimum is still required to confirm the presence of the variant. If RT – PCR assays specific to signature mutations for variants of concern become available, these can be used for more rapid and comprehensive screening for specific variants. If such assays are implemented, it is important that the assays are validated for their purpose and that the results are interpreted by staff with molecular biology traini ng. Results should be confirmed by sequencing if possible. If prevention of importation of a variant is a priority, development of such RT – PCR assays is crucial. Until now, there has not been any report that the new variant viruses would negatively impact r apid a ntigen d etection t ests . Since most of the commercially available r apid a ntigen d etection t ests are based on the detection of the SARS – CoV – 2 nucleoprotein protei n , their performance should not be affected by changes in the spike protein . A few r apid a ntigen d etection t ests are based on detection of the spike protein and therefore it cannot be ruled out that the identified mutations will not have an effect on them . However, a ccording to the UK, five lateral flow devices, all targeting the nucleocapsid protein which has two amino acid changes for VOC 202 012/01 (D3L and S235F) , validated by the UK still meet minimum performance criteria for this variant [76] . Evidence for increased transm issibility of VOC 202012/01 Several recent modelling studies based on epidemiological data, including the proportion of VOC 202012/01, indicate that the variant is significantly more transmissible than previously circulating variants , even though there are significant uncertainties regarding the magnitude of the increase . The estimates are given either as an additive increase in the reproductive number (R) or as a multiplicative increase in the transmissibility. It is important to note that any est imated increase in R is specific to the situation where it was measured, in this case the situation in South – East England during the period October December 2020. Preliminary findings that there may be an association between infection with the variant and increased viral load indicate the likelihood of i ncreased viral load in respiratory samples , which is probably associated with increased shedding of virus and greater transmissibility . Modelling s tudies on the variant VOC 202012/01 NERVTAG reported that ba sed on preliminary analysis of genomic data , an increase could be expected in the case number growth rate f o r VOC 202012/01 of 71% (95% CI: 67% – 75%) , which was higher than that for other SARS – C o V – 2 variants. In addition, correlation studies estimated an absolute increase in the R – value of between 0.39 and 0.93 . Using a mixed regression model, the variant frequency was significantly associated with an increase of the time – dependent reproductive nu mber (Rt), estimated by a Bayesian semi – mechanistic transmission model. The increase in Rt was estimated to be 0.74 [95% CI: 0.44 – 1.29] using a random effect model [56] . Complementary analysis by the Centre for Mathematical Modelling of Infectious Diseases (CMMID) using a n age – and regionally structured mathematical model with multiple epidemiological indicators across seven National Health Service (NHS) England regions an d genomic surveillance from the COVID – 19 Genomics UK Consortium estimated that the variant is 56% more transmissible (95% CI: 50 – 74%) than pre – existing circulating variants of SARS – CoV – 2 . The study does not report that VOC cases were more likely to require hospitalisation or die than cases resulting from pre – existing variants . In addition, four alternative scenarios (increased infectiousness, immune escape, increased susceptibility among children and shorter generation time) have been evaluated against the observed data. The increase d infectiousness of the variant was the best able to reproduce the observed relative growth rate of VOC 202012/01 [77] and fit the observed increase in hospitalisations in the NHS regions throughout the East of England, London and the South East in Decembe r 2020. Modelling studies using S – gene drop – out as a proxy for the frequency of VOC 202012/01 Using S – gene drop – out as a proxy for the frequency of VOC 202012/01 during weeks 44 49 2020, the ratio of the weekly growth factors of the S – gene negative cases against S – positive cases was 1.47 (95% CI: 1.34 – 1.59) [56] . Following a dditional analysis applying the Bayesian semi – mechanistic transmission model methodology above , the estimated a dditive effect in a mixed regression model was of the same range , estimated at 0.60 ( 95% CI: 0.48 – 0.73 ) [56] . Possible impact of VOC 202012/01 on vaccine match and effectiveness There is currently not enough information available to assess whether VOC 202012/01 poses a risk to vaccine match and effectiveness. No phenotypic data ar e available for the new variant and no data are available on the ability of antibodies
271 KB – 26 Pages