[4] After 2000, Thacker wrote for publications such as The New Republic and Salon and was a staff writer with Environmental Science & Technology, a journal of the American Chemical Society (ACS).
Here he published a series of exposés that a senior ACS official claimed showed an anti-industry bias, culminating in an article on the Weinberg Group that resulted in him being fired by the journal in 2006.
In November 2021, The BMJ published a piece by Thacker alleging there has been "poor practice" at Ventavia, one of the companies involved in the phase III evaluation trials of the Pfizer vaccine.
Questioning Thacker's work in Science-Based Medicine, David Gorski wrote that his article presented facts without necessary context to misleading effect, playing up the seriousness of the noted problems.
Prominent vaccination expert Paul Offit has criticized the issues outlined in the report as being vague and has cautioned against assuming the claims made in it are true.
The award judges said “[t]his was expertly researched and written journalism on a subject of huge national importance.”[24][25] Thacker has been persistently critical of organizations that seek to identify disinformation and dampen its influence.
Thacker was specifically critical of Hotez's call for institutional assistance in supporting the message of vaccine researchers, labeling it as "Police Deployment against "Anti-Vaxxers"".