Omicron breakthrough infection in individuals vaccinated with BNT162b2 boosts not only neutralizing activity and BMEM cells against Omicron but broadly expands immunity against various variants of concern. Read more about this study under Article 3.
- Article 1: Protection against SARS-CoV-2 after COVID-19 vaccination and previous infection
- Article 2: FcγR-mediated SARS-CoV-2 infection of monocytes activates inflammation
- Article 3: Omicron breakthrough infection drives cross-variant neutralization and memory B cell formation
- Article 4: Molecular consequences of SARS-CoV-2 liver tropism
Article 1: Protection against SARS-CoV-2 after COVID-19 vaccination and previous infection
Previous studies have shown that two doses of the Pfizer-BioNTech vaccine (BNT162b2) provide high short-term protection against SARS-CoV-2 infection. However, this protection wanes significantly after 6 months. This study reports that persons who previously got infected with SARS-CoV-2 and who were subsequently vaccinated were less likely to get another COVID-19 infection as compared to those who did not get vaccinated after their infection. The protection lasted more than 1 year after initial infection. In summary: Persons infected with COVID-19 who are vaccinated have a higher protection against another infection than unvaccinated persons.
Article 2: FcγR-mediated SARS-CoV-2 infection of monocytes activates inflammation
The study indicates that two types of white blood cells (macrophages in the lungs, and monocytes in the blood) trigger inflammation once infected with the SARS-CoV-2 virus. The authors provide evidence that the virus can infect and replicate in immune cells. They were also able to show how SARS-CoV-2 can enter immune cells; the virus entered lung macrophages through the limited number of ACE2 receptors and monocytes through the Fcγ receptor, another surface protein. In summary: Immune cells infected with SARS-CoV-2 can trigger a massive inflammatory response that contributes to severe COVID-19.
Article 3: Omicron breakthrough infection drives cross-variant neutralization and memory B cell formation
The B cell memory pool is a critical determinant of an individual’s ability to respond to newly emerging variants. Memory B cells (BMEM) are the basis of the recall response upon antigen reencounter either by infection or booster vaccination. Omicron breakthrough infection in individuals vaccinated with BNT162b2 boosts not only neutralizing activity and BMEM cells against Omicron but broadly expands immunity against various variants of concern. In summary: Breakthrough infection in individuals double- and triple-vaccinated with BNT162b2 leads to protection against various variants of concern and memory B cell formation.
Article 4: Molecular consequences of SARS-CoV-2 liver tropism
Previous studies described SARS-CoV-2 as a multi-organ virus. This study shows that the virus directly affects the liver. Elevated liver values were detected in COVID-19 patients (majority without a history of liver disease) on admission to the hospital. In some cases, the virus could be isolated from the liver as an active pathogen. Molecular and bioinformatics analyses showed that SARS-CoV-2 infection can significantly alter cellular programs in the liver, similar to different forms of hepatitis. In summary: COVID-19 affects the liver, leading to inflammation and altered metabolic programs that could have long-term consequences.
 Hall V et al. Protection against SARS-CoV-2 after Covid-19 Vaccination and Previous Infection. N Engl J Med. 2022 Mar 31;386(13):1207-1220. doi: 10.1056/NEJMoa2118691. Epub 2022 Feb 16. PMID: 35172051; PMCID: PMC8908850. https://www.nejm.org/doi/10.1056/NEJMoa2118691
 Junqueira C et al. FcγR-mediated SARS-CoV-2 infection of monocytes activates inflammation. Nature. 2022 Jun;606(7914):576-584. doi: 10.1038/s41586-022-04702-4. Epub 2022 Apr 6. PMID: 35385861. https://www.nature.com/articles/s41586-022-04702-4
 Quandt J et al. Omicron BA.1 breakthrough infection drives cross-variant neutralization and memory B cell formation against conserved epitopes. Sci Immunol. 2022 Jun 2:eabq2427. doi: 10.1126/sciimmunol.abq2427. Epub ahead of print. PMID: 35653438; PMCID: PMC9162083. https://www.science.org/doi/10.1126/sciimmunol.abq2427
 Wanner N et al. Molecular consequences of SARS-CoV-2 liver tropism. Nat Metab. 2022 Mar;4(3):310-319. doi: 10.1038/s42255-022-00552-6. Epub 2022 Mar 28. PMID: 35347318; PMCID: PMC8964418. https://www.nature.com/articles/s42255-022-00552-6