When we updated our review of the evidence of pre and asymptomatic transmission of SARS CoV-2, our first search was carried out on 31 March 2021. This identified 145 possible studies for inclusion. Using our framework as a measure of the study design's reliability, we could discard all but 18, or 12.5% of the total. A year later, we updated the search, showing the ratio was 5 to 1.

Share

In the context of research waste, these findings alone pose several problems.

First, they suggest that as the spotlight moves away, so does researcher’s interest: a shallow, fallow indictment of the seriousness and probity of some of our colleagues.

Second, as we have pointed out countless times, the quality of research was abysmal, as evidenced by our attrition rate to find studies that could answer the question.

The evidence from systematic reviews reported that Mass Testing With Contact Tracing was low-quality. The Low-quality evidence mainly consisted of models relying on assumptions, not what happens on the ground. However, this didn't stop experts from modelling all sorts of claims in August Journals, such as weekly COVID-19 testing with household quarantine and contact tracing, which would “probably end the epidemic”. 

Third, to our knowledge, no attempt has been made to standardise methodologies in molecular epidemiology married to clinical medicine and epidemiology to study transmission despite the formidable tools to do so now in our grasp.

Fourth, our conclusions on whether pre and asymptomatics can transmit SARS-CoV-2 are based on a few better studies in heterogeneous situations. The knowledge base should be expanded considerably, not just on one agent but on several, in fact, all known ones.

Fifth, the issue of pre and asymptomatic transmission is not an ivory tower obsession of two old geezers. The rationale for the mass testing that in England cost 37 billion GBP was based on the presence of symptomless spreaders, akin almost to medieval “untori”, as we have explained and will do again in the Riddle series. 

The possibility of the existence of untori and the fear the concept generated -  the viral assassin striking in the dark, was a major weapon to control the populace and ensure they obeyed the rule of the day. 

Readings

Jefferson T, Heneghan CJ, Spencer E, Brassey J, Plüddemann A, Onakpoya I, Evans D, Conly J. A Hierarchical Framework for Assessing Transmission Causality of Respiratory Viruses. Viruses. 2022 Jul 22;14(8):1605. doi: 10.3390/v14081605. 

Tom Jefferson, Elisabeth A Spencer, Jon Brassey, Carl Heneghan, Viral Cultures for Coronavirus Disease 2019 Infectivity Assessment: A Systematic Review, Clinical Infectious Diseases, Volume 73, Issue 11, 1 December 2021, Pages e3884–e3899, https://doi.org/10.1093/cid/ciaa1764

Jefferson T, Spencer EA, Onakpoya IJ, Plüddemann A, Conly JM, Heneghan CJ. Transmission of SARS-CoV-2 from pre and asymptomatic infected individuals: a systematic review update. Clin Microbiol Infect. 2022 Nov;28(11):1511-1512. doi: 10.1016/j.cmi.2022.06.016. Epub 2022 Jun 28. PMID: 35777603; PMCID: PMC9238017.