Viral load of SARS-CoV-2 Omicron BA.5 is lower than that of BA.2 despite the higher infectivity of BA.5.
BA.5
COVID-19
Omicron variant
SARS-CoV-2
viral load
Journal
Immunity, inflammation and disease
ISSN: 2050-4527
Titre abrégé: Immun Inflamm Dis
Pays: England
ID NLM: 101635460
Informations de publication
Date de publication:
Feb 2023
Feb 2023
Historique:
revised:
25
01
2023
received:
08
12
2022
accepted:
30
01
2023
entrez:
25
2
2023
pubmed:
26
2
2023
medline:
3
3
2023
Statut:
ppublish
Résumé
Sublineage BA.5 of the SARS-CoV-2 Omicron variant rapidly spread and replaced BA.2 in July 2022 in Tokyo. A high viral load can be a possible cause of high transmissibility. The copy numbers of SARS-CoV-2 in nasopharyngeal swab samples obtained from all patients visiting the hospital where this research was conducted were measured using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Viral genotypes were determined using PCR-based melting curve analysis. Next, whole-genome sequencing was performed using approximately one fifth of the samples to verify the viral genotypes determined using PCR. Then, the copy numbers of the BA.1, BA.2, and BA.5 cases were compared. Contrary to expectations, the copy numbers of the BA.5 cases (median 4.7 × 10 The results presented here suggest that the increased infectivity of BA.5 is not caused by higher viral loads, but presumably by other factors such as increased affinity to human cell receptors or immune escape due to its L452R mutation.
Sections du résumé
BACKGROUND
BACKGROUND
Sublineage BA.5 of the SARS-CoV-2 Omicron variant rapidly spread and replaced BA.2 in July 2022 in Tokyo. A high viral load can be a possible cause of high transmissibility.
METHODS AND RESULTS
RESULTS
The copy numbers of SARS-CoV-2 in nasopharyngeal swab samples obtained from all patients visiting the hospital where this research was conducted were measured using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Viral genotypes were determined using PCR-based melting curve analysis. Next, whole-genome sequencing was performed using approximately one fifth of the samples to verify the viral genotypes determined using PCR. Then, the copy numbers of the BA.1, BA.2, and BA.5 cases were compared. Contrary to expectations, the copy numbers of the BA.5 cases (median 4.7 × 10
CONCLUSION
CONCLUSIONS
The results presented here suggest that the increased infectivity of BA.5 is not caused by higher viral loads, but presumably by other factors such as increased affinity to human cell receptors or immune escape due to its L452R mutation.
Identifiants
pubmed: 36840495
doi: 10.1002/iid3.783
pmc: PMC9933202
doi:
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
e783Subventions
Organisme : JST-CREST
ID : JPMJCR20H2
Organisme : Japan Agency for Medical Research and Development
ID : 20nk0101612h0901
Informations de copyright
© 2023 The Authors. Immunity, Inflammation and Disease published by John Wiley & Sons Ltd.
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