Excluding Participants With Mycobacteria Infections From Clinical Trials: A Critical Consideration in Evaluating the Efficacy of BCG Against COVID-19

In the context of the coronavirus disease 2019 (COVID-19) pandemic, Bacillus CalmetteGuérin (BCG), a tuberculosis (TB) vaccine, has been investigated for its potential to prevent COVID-19 with conflicting outcomes. Currently, over 50 clinical trials have been conducted to assess the effectiveness of BCG in preventing COVID-19, but the results have shown considerable variations. After scrutinizing the data, it was discovered that some trials had enrolled individuals with active TB, latent TB infection, or a history of TB. This finding raises concerns about the reliability and validity of the trial outcomes. In this study, we explore the potential consequences of including these participants in clinical trials, including impaired host immunity, immune exhaustion, and the potential masking of the BCG vaccine’s protective efficacy against COVID-19 by persistent mycobacterial infections. We also put forth several suggestions for future clinical trials. Our study underscores the criticality of excluding individuals with active or latent TB from clinical trials evaluating the efficacy of BCG in preventing COVID-19.

Will Mutations in the Spike Protein of SARS-CoV-2 Lead to the Failure of COVID-19 Vaccines?

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19), which has spread worldwide since it was first identified in Wuhan, China, at the end of 2019. With the global transmission of the virus, a large number of SARS-CoV-2 variants have also appeared, especially, emerging strains that have recently been discovered in the United Kingdom (variant 20I/501Y.V1, lineage B.1.1.7), South Africa (variant 20H/501Y.V2, lineage B.1.351), and Brazil (variant 20 J/501Y.V3, and lineage P.1). The common feature of these variants is that they share the N501Y mutation involving the SARS-CoV-2 spike (S) protein, which is precisely the target of most COVID-19 vaccines. Furthermore, mutations such as N501Y, E484K, and K417N in the S protein may affect viral fitness and transmissibility. However, current research on the impact of these variants on COVID-19 vaccines is still lacking. Herein, we briefly explain why most COVID-19 vaccines target the S protein, update the progress of research regarding S protein-related COVID-19 vaccines, review the latest studies concerning the effects of S protein variants on COVID-19 vaccines, and finally, propose certain strategies to deal with SARS-CoV-2 variants.

Will Mutations in the Spike Protein of SARS-CoV-2 Lead to the Failure of COVID-19 Vaccines?

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19), which has spread worldwide since it was first identified in Wuhan, China, at the end of 2019. With the global transmission of the virus, a large number of SARS-CoV-2 variants have also appeared, especially, emerging strains that have recently been discovered in the United Kingdom (variant 20I/501Y.V1, lineage B.1.1.7), South Africa (variant 20H/501Y.V2, lineage B.1.351), and Brazil (variant 20 J/501Y.V3, and lineage P.1). The common feature of these variants is that they share the N501Y mutation involving the SARS-CoV-2 spike (S) protein, which is precisely the target of most COVID-19 vaccines. Furthermore, mutations such as N501Y, E484K, and K417N in the S protein may affect viral fitness and transmissibility. However, current research on the impact of these variants on COVID-19 vaccines is still lacking. Herein, we briefly explain why most COVID-19 vaccines target the S protein, update the progress of research regarding S protein-related COVID-19 vaccines, review the latest studies concerning the effects of S protein variants on COVID-19 vaccines, and finally, propose certain strategies to deal with SARS-CoV-2 variants.

The 4 year follow-up investigation of cognitive function in patients after acute stroke / 中华老年医学杂志

Objective To investigate the 4-year follow up of cognitive function outcomes and characteristics in patients after stroke.Methods Sixty three cases according with the diagnostic standard of acute unifocal subcortical stroke were consecutively collected in neurological ward from December 2009 to November 2010.They were followed up for average four years.Forty one out of them completed the neuropsychology tests identical to the baseline,which covered the general cognition function,attention,execution,memory,language,spatial,etc.According to the standard of clinical diagnosis,cognition function is divided into five degrees,including normal,VCI-ND,mild VaD,moderate VaD,and severe VaD.The improved group had 13 cases whose cognition function was improved by one or more ranks.The progressive group had 12 cases whose cognition function progressed by one or more ranks.The stable group had 16 cases whose cognition function remained the same as the baseline.Results According to qualitative analysis on the baseline versus 4-year follow-up outcome,in 13 improved cases,8 were VCI-ND and 5 were mild VaD.In 16 stable cases,11 were normal,4 were VCI-ND and 1 was mild VaD.In 12 progressive cases,3 were normal (change to mild VaD after follow-up),5 were VCI-ND (change to mild and moderate VaD after follow-up) and 4 were mild VaD (change to moderate VaD after 4-year follow-up).In the comparison of baseline cognition function among the improved,progressive and stable group,there was only one significantly different score (the right number of SCWT-A) in the improved and progressive group.The cognition function of improved group had significant differences in CFT-copy,right number of SCWT-C and the time of TMT-B before versus after follow-up.The cognition function of progressive group had significant differences in AVLT-Delay Recall and CFT-Recall.Conclusion Long-term cognitive function outcome after stroke is heterogenetic.The location of cognitive impairment or progression is not the same model for different cognitive outcome group.

A comparison study on auditory verbal learning ability among four different brain areas after stroke / 中华老年医学杂志

Objective To compare the ability of auditory verbal learning,memory and retention between each side of thalamus and basal ganglia after stroke.Methods 63 patients with single lesion in thalamus or basal ganglia after stroke,34 patients with amnestic mild cognitive impairment (aMCI)and 34 healthy control subjects received auditory verbal learning test.Results There was an overall decline of immediate and delayed recall,retention ability in patients with single lesion of stroke as compared with the healthy control group(P＜0.05).Both the left thalamic stroke group [(19.0± 3.1)scores]and aMCI group[(17.6 ±3.3)scores]showed similar pattern in damaged recognition ability,while this ability still existed in the other three stroke groups.The ability of auditory verbal learning in the left thalamic stroke group[(2.2 ± 2.0)scores]and right thalamic stroke group[(2.1 ± 1.9)scores]were lower than in the healthy control group[(3.6 ± 1.8)scores](P ＜0.05).The retention ability in the left thalamus stroke group[(2.8±1.7)scores]and the right basal ganglia stroke group[(2.7 ± 1.9)scores]was decreased than in the healthy control group[(1.7±1.4)scores](P＜0.05).Conclusions There is decline of AVLT-learning,memory and retention ability in patients with single lesion stroke,especially in the left thalamus stroke patients.Moreover,the pattern of impairment in the left thalamus stroke is similar to aMCI but different from the other three stroke groups.