From the Curator-in-Chief's Desk—May 14, 2021

This week, the CDC issued new mask guidance for fully immunized individuals, recommending that individuals do not need to wear a mask for indoor or outdoor activities 2 weeks after their final vaccine dose. Over 35% of the U.S. population is fully immunized. However, the CDC still recommends everyone continue to wear a mask at medical facilities and when traveling using public transportation.

Adolescents are also now eligible for a COVID-19 vaccine. This past week, the U.S. Food and Drug Administration (FDA) expanded the emergency use authorization of the Pfizer and BioNTech BNT162b2 vaccine to include those aged 12 to 15 years old. The BNT162b2 vaccine was found to be 100% effective in this age group at preventing COVID-19. Using real-world data from Israel, Haas, E., et al. demonstrated the BNT162b2 vaccine is over 90% effective at preventing symptomatic and asymptomatic COVID-19. The authors also found the vaccine effective against the B.1.1.7 variant lineage, which matches with Abu-Raddad, L., et al. estimated BNT162b2 vaccine efficacy of 89.5% against the B.1.1.7 variant lineage and 75% against the B.1.351 variant lineage. Additionally, Liu, Y., et al. analyzed neutralization of sera from BNT162b2 vaccinated individuals against the B.1.526 and B.1.429 variant lineages, finding neutralization levels were similar as compared to neutralization of the SARS-CoV-2 reference strain. These data indicate that vaccines may be effective against circulating variants.

To increase vaccine efficacy against variants, Wu, K., et al. administered a booster mRNA vaccine encoding the B.1.351 lineage spike protein to 20 individuals previously fully vaccinated with the Moderna mRNA-1273 vaccine. After the booster vaccination, the authors reported increased neutralization titers to the SARS-CoV-2 reference strain, as well as to the B.1.351 and P.1 lineage strains, than before the booster. Researchers also are developing a pancoronavirus vaccine effective against multiple coronaviruses that infect humans. Saunders, K., et al. developed a multimeric SARS-CoV-2 receptor-binding domain nanoparticle vaccine to induce a known cross-reacting, neutralizing antibody. In nonhuman primates, immunization with this vaccine elicited neutralizing antibody responses against the SARS-CoV-2 reference strain, B.1.1.7, P.1 and B.1.351 variant lineages, SARS-CoV-1, as well as bat-specific coronaviruses. Based on these results, the authors suggest that current COVID-19 vaccines can induce cross-neutralizing antibody responses that may protect against future zoonotic coronaviruses.

This year, ASM Microbe is part of World Microbe Forum, a collaboration between ASM, FEMS, ASLM and ASV, taking place online 20-24 June 2021. This unique, global, online meeting will bring together researchers, industry professionals, students, educators and leaders in the microbial sciences from across the world all in one place. The registry will host the session “COVID-19 Research Registry: A Year of Progress” where some of our curators will provide an update on the advancement of SARS-CoV-2 research. Registration is open, and we hope you can join us at World Microbe Forum.

Lynn Enquist, Ph.D.

 

 

 

May 7, 2021

By Catherine J. Pachuk, Ph.D., Chief Science Officer, Marizyme, Inc., Jupiter, Fla. Dr. Pachuk is one of the curators of the Registry.
 
“Neutralizing Response against Variants after SARS-CoV-2 Infection and One Dose of BNT162b2” by Lustig, Y., et al., published in The New England Journal of Medicine on April 7, 2021.
 
Several vaccines have been authorized in the U.S. and elsewhere for prevention of COVID-19 disease; however, concerns exist regarding the potential for emerging viral variants to escape vaccine protection. The concerns are largely driven by reductions in variant-specific neutralizing antibody (Ab) titers in vaccinated and convalescent individuals compared to responses directed against the original lineage virus. Relative reductions in neutralizing Ab titers vary depending upon the variant, ranging from only modest reductions observed for B.1.1.7 to more significant reductions observed for B.1.351.
 
Recently, Lustig et al. reported substantial increases in neutralizing responses to original and variant viruses in previously infected individuals following administration of a single dose of the Pfizer BNT162b2 vaccine. Neutralizing Ab titers were measured in serum samples obtained from subjects 1-12 weeks following natural infection, immediately prior to vaccination and 1-2 weeks after single dose vaccine administration, in microneutralization assays using isolates of the original virus or variants. Geometric mean titers for neutralizing activity in serum samples collected post-natural infection were 456, 256, 71 and 8 respectively for the original B1 lineage virus, B.1.1.7, P1 and B.1.351. Prior to vaccination, titers dropped to 81, 40, 36 and 7, but following vaccination substantially increased to 9195, 8192, 2896 and 1625 respectively for B.1, B.1.1.7, P1 and B.1.351. These data demonstrate the potential of the current vaccine, when administered to those with prior infection, to drive high neutralizing Ab titers against current variants of concern, including B.1.351 for which there was low to undetectable neutralization activity prior to vaccination.
 
Likewise, a previously published study documented significant increases in anti-spike Abs following a single dose of the Pfizer vaccine in individuals with prior infection. It is not known if prior infection is required to achieve these increased responses post-vaccination or whether a series of vaccine boosters can achieve similar results. The study, although limited by small sample size, minimally underscores the importance of vaccinating previously infected individuals.

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