About vaccines

New study findings highlight the need for a rapid booster vaccine campaign to prevent COVID-19 caused by the Omicron variant since the neutralization of Omicron by the two-dose BNT162b2 vaccine is not effective in controlling the spread of the infection. // 30.12.2021

New study findings showed that the SARS-CoV-2 breakthrough infections are rare and show mild or asymptomatic profiles generally. The breakthrough infection occurs early after vaccination in almost 50% of the cases within 70 to 80 days post full vaccination. // 30.12.2021

A new study found increases in resting memory B cell subsets showed strong cross-reactivity against several variants, including Omicron. // 29.12.2021

Researchers assess the real-world effectiveness of a third booster dose of the Pfizer-BioNTech BNT162b2 vaccine against the initial two-dose regimen. // 29.12.2021

Researchers evaluate vaccine effectiveness against SARS-CoV-2 Omicron and Delta variants. // 29.12.2021

New U.K. data suggest steep drop-off in protection, potentially giving Omicron more power // 28.12.2021

Research suggests that a single booster dose of NVX-CoV2373 given approximately six months after the primary series induced significant increases in humoral antibodies, while also exhibiting an acceptable safety profile. // 29.12.2021

A new study shows that Omicron is more infectious than any of the other variants and that booster vaccines, especially mRNA vaccines, are capable of neutralizing Omicron variants of pseudoviruses. // 29.12.2021

A new study found that the presence of a subset of antibodies with broad neutralizing activities against all circulating variants of concern in the three-dose vaccines' memory B-derived antibody repertoire suggests that the Omicron/future variants infection may elicit selective and rapid recall of humoral responses, conferring secondary protection directed by memory etched in the immune system. // 29.12.2021

Researchers assess vaccine effectiveness of two and three doses of BNT162b2 against SARS-CoV-2 infections and COVID-19-related hospital admission. // 28.12.2021

A new preprint* research paper under consideration at Nature Portfolio Journal assesses the susceptibility of the Omicron variant to neutralizing antibody response after booster immunization. // 28.12.2021

The findings reveal that the Omicron neutralizing titers induced by the third vaccine dose are comparable to that achieved against the original Wuhan strain (wild-type SARS-CoV-2) by the two-dose regimen. // 28.12.2021

A new research letter evaluates whether the estimated vaccine effectiveness changes against infection over time. // 28.12.2021

New findings suggest that the Pfizer-BioNTech mRNA COVID-19 vaccines provide extra protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) than AstraZeneca. // 24.12.2021

The Omicron variant of concern (VOC) is a rapidly spreading variant of SARS-CoV-2 that is likely to overtake the previously dominant Delta VOC in many countries by the end of 2021. We estimated the transmission dynamics following the spread of Omicron VOC within Danish households during December 2021. We used data from Danish registers to estimate the household secondary attack rate (SAR). Among 11,937 households (2,225 with the Omicron VOC), we identified 6,397 secondary infections during a 1-7 day follow-up period. The SAR was 31\% and 21\% in households with the Omicron and Delta VOC, respectively. We found an increased transmission for unvaccinated individuals, and a reduced transmission for booster-vaccinated individuals, compared to fully vaccinated individuals. Comparing households infected with the Omicron to Delta VOC, we found an 1.17 (95\%-CI: 0.99-1.38) times higher SAR for unvaccinated, 2.61 times (95\%-CI: 2.34-2.90) higher for fully vaccinated and 3.66 (95\%-CI: 2.65-5.05) times higher for booster-vaccinated individuals, demonstrating strong evidence of immune evasiveness of the Omicron VOC. Our findings confirm that the rapid spread of the Omicron VOC primarily can be ascribed to the immune evasiveness rather than an inherent increase in the basic transmissibility. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement Frederik Plesner Lyngse: Independent Research Fund Denmark (Grant no. 9061-00035B.); Novo Nordisk Foundation (grant no. NNF17OC0026542); the Danish National Research Foundation through its grant (DNRF-134) to the Center for Economic Behavior and Inequality (CEBI) at the University of Copenhagen. Laust Hvas Mortensen is supported in part by grants from the Novo Nordisk Foundation (grant no. NNF17OC0027594, NNF17OC0027812). Matthew Denwood, Lasse Christiansen and Carsten Kirkeby receive funding from Statens Serum Institut as part of the Expert Group for Mathematical Modelling of COVID-19. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The data used in this study are available under restricted access due to Danish data protection legislation. The data are available for research upon reasonable request to The Danish Health Data Authority and Statens Serum Institut and within the framework of the Danish data protection legislation and any required permission from Authorities. We performed no data collection or sequencing specifically for this study. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. // 27.11.2021

A new study suggests that the immune response against severe acute respiratory syndrome coronavirus 2 is greater with a three-dose regimen than a two-dose regimen. // 24.12.2021

New research reported in the journal The Lancet examines the temporal association between the two-dose ChAdOx1 nCoV-19 (Oxford-AstraZeneca) vaccination regimen and the risk of severe outcomes from COVID-19 in Scotland vs. Brazil, where the Delta variant of SARS-CoV-2 was dominant and rare, respectively. // 21.12.2021

In a recent study, published in the Annals of Internal Medicine, scientists conducted a target trial emulation study and documented that among the elderly in the U.S. (with significant comorbidities), the efficacy of messenger RNA (mRNA) vaccines was much lower in terms of preventing infection, than previously reported. // 21.12.2021

Researchers determined IgG titers of vaccinated healthcare workers 11 months following primary COVID-19 vaccination. // 21.12.2021

Researchers recently developed an immunodiagnostic T cell assay to classify T cell immune responses of the subjects based on their coronavirus disease 2019 infection and vaccination history. // 21.12.2021

A new study discusses the necessity and role of pneumococcal immunization in strengthening the global health system amid the current COVID-19 pandemic. // 22.12.2021

Meilahden sairaalassa diagnosoitiin aivoverenkiertohäiriöitä koronavirusrokotusten aikana vähemmän kuin vastaavana aikana ennen epidemian alkua. Huoli tukosten lisääntymisestä on aiheeton. // 22.12.2021

Nature Reviews Neurology - Rare neurological complications can occur after COVID-19 vaccination, but recent studies show that such complications are much more common after SARS-CoV-2 infection.... // 20.12.2021

Some people may not know they are infected when they get boosted // 17.12.2021

The authors highlight that their research confirms the effectiveness of two doses of mRNA-1273 against SARS-CoV-2 infection. // 16.12.2021

A new study suggests that low GBS incidence in vaccinated patients compared to non-vaccinated people should encourage the active propagation of vaccination against SARS-CoV-2. // 14.12.2021

A new preprint describes the results of a study examining this aspect of the disease. // 14.12.2021

A recent observational study in Israel evaluates the efficacy of a Pfizer vaccine booster dose in reducing the mortality rate of COVID-19. // 12.12.2021

Study reveals that the most beneficial vaccination strategy is to distribute all available doses of COVID-19 vaccines predominantly for primary vaccinations and the remaining doses for boosters. // 12.12.2021

Nature Communications - The UK extended the interval until the second COVID-19 vaccine dose up to 12 weeks. // 10.12.2021