Effectiveness of a bivalent mRNA vaccine dose against symptomatic SARS-CoV-2 infection among U.S. healthcare personnel, September 2022–May 2023

Details

• Alternative Title:
  Vaccine
• Personal Author:
  Plumb, Ian D. ; Hagen, Melissa Briggs ; Wiegand, Ryan ; Dumyati, Ghinwa ; Myers, Christopher ; Harland, Karisa K. ; Krishnadasan, Anusha ; Gist, Jade James ; Abedi, Glen ; Fleming-Dutra, Katherine E. ; Chea, Nora ; Lee, Jane E. ; Kellogg, Melissa ; Edmundson, Alexandra ; Britton, Amber ; Wilson, Lucy E. ; Lovett, Sara A. ; Ocampo, Valerie ; Markus, Tiffanie M. ; Smithline, Howard A. ; Hou, Peter C. ; Lee, Lilly C. ; Mower, William ; Rwamwejo, Fernand ; Steele, Mark T. ; Lim, Stephen C. ; Schrading, Walter A. ; Chinnock, Brian ; Beiser, David G. ; Faine, Brett ; Haran, John P. ; Nandi, Utsav ; Chipman, Anne K. ; LoVecchio, Frank ; Eucker, Stephanie ; Femling, Jon ; Fuller, Matthew ; Rothman, Richard E. ; Curlin, Marcel E. ; Talan, David A. ; Mohr, Nicholas M.
• Corporate Authors:
  Vaccine Effectiveness among Healthcare Personnel Study Team
• Description:
  Background
  
  Bivalent mRNA vaccines were recommended since September 2022. However, coverage with a recent vaccine dose has been limited, and there are few robust estimates of bivalent VE against symptomatic SARS-CoV-2 infection (COVID-19). We estimated VE of a bivalent mRNA vaccine dose against COVID-19 among eligible U.S. healthcare personnel who had previously received monovalent mRNA vaccine doses.
  
  Methods
  
  We conducted a case-control study in 22 U.S. states, and enrolled healthcare personnel with COVID-19 (case-participants) or without COVID-19 (control-participants) during September 2022–May 2023. Participants were considered eligible for a bivalent mRNA dose if they had received 2–4 monovalent (ancestral-strain) mRNA vaccine doses, and were ≥67 days after the most recent vaccine dose. We estimated VE of a bivalent mRNA dose using conditional logistic regression, accounting for matching by region and four-week calendar period. We adjusted estimates for age group, sex, race and ethnicity, educational level, underlying health conditions, community COVID-19 exposure, prior SARS-CoV-2 infection, and days since the last monovalent mRNA dose.
  
  Results
  
  Among 3,647 healthcare personnel, 1,528 were included as case-participants and 2,119 as control-participants. Participants received their last monovalent mRNA dose a median of 404 days previously; 1,234 (33.8%) also received a bivalent mRNA dose a median of 93 days previously. Overall, VE of a bivalent dose was 34.1% (95% CI, 22.6%–43.9%) against COVID-19 and was similar by product, days since last monovalent dose, number of prior doses, age group, and presence of underlying health conditions. However, VE declined from 54.8% (95% CI, 40.7%–65.6%) after 7–59 days to 21.6% (95% CI 5.6%–34.9%) after ≥60 days.
  
  Conclusions
  
  Bivalent mRNA COVID-19 vaccines initially conferred approximately 55% protection against COVID-19 among U.S. healthcare personnel. However, protection waned after two months. These findings indicate moderate initial protection against symptomatic SARS-CoV-2 infection by remaining up-to-date with COVID-19 vaccines.
  
  
• Subjects:
  Case-Control Studies COVID-19 COVID-19 Vaccines Delivery Of Health Care Humans Infant, Newborn MRNA Vaccines RNA, Messenger SARS-CoV-2 Vaccines, Combined
• Keywords:
  Bivalent COVID-19 Vaccines Healthcare Personnel MRNA Vaccines Vaccine Effectiveness
• Source:
  Vaccine. 42(10):2543-2552
• Pubmed ID:
  37973512
• Pubmed Central ID:
  PMC10994739
• Document Type:
  Journal Article
• Funding:
  CC999999/ImCDC/Intramural CDC HHSUnited States/ ; U01 CK000643/CK/NCEZID CDC HHSUnited States/ ; U01CK000480/ACL/ACL HHSUnited States/ ; UL1 TR002537/TR/NCATS NIH HHSUnited States/
• Volume:
  42
• Issue:
  10
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha-512:1139fe9fc3dd83fcacb6307305411665bc7e62914c4302d466ac97db19d18d4d2f3a717ca3c3d9034c7446ada33e0eaa30ca092f0de961aba89179d2848355bb
• Download URL:
  https://stacks.cdc.gov/view/cdc/154087/cdc_154087_DS1.pdf
• File Type:
  [PDF - 330.82 KB ]