For decades, dozens of scientific papers have suggested that masks are ineffective at preventing disease transmission. Both the WHO and Dr Fauci corroborated that claim as recently as March 2020. In that same month, there was a sudden flip, we were told that masks would protect us from COVID, despite claims to the contrary from the mask manufacturers. By September 2020 the head of the CDC claimed in testimony before a US Senate subcommittee, that masks were more effective at preventing COVID than vaccines.
Despite the now “conventional wisdom” that masks prevent the spread of viruses, there are numerous studies that show they do not. Interestingly, there is even research showing that operating-room personnel’s face masks during surgery had no effect on whether the patient developed a subsequent infection.
The CDC’s own data reveal that those who wear masks get infected with COVID at the same rate as those who don’t. Indeed,85% of those infected with COVID wore masks some or all of the time before their infection.
Countless jurisdictions that mandated masks actually saw an increase in infections during the mandates compared to non-mandated jurisdictions.
Only two randomized controlled studies were conducted during COVID. The first in Denmark found no benefit in mask-wearing,  and the second conducted in Bangladesh concluded that there was a small benefit to using medical masks, but not with cloth masks. The masked group of 178,322 participants had just 20 fewer symptomatic infections than the control group – over an 8 week period. The study’s methodology and conclusions were criticized from a number of angles.
Even if masks were slightly effective, one must also consider the negative effects of continuous mask-wearing. These include a decrease in oxygen intake levels,    headaches, Mask-Induced Exhaustion Syndrome (MIES), reduced immunity, increased germ load, and skin reactions.
A randomized controlled study conducted prior to COVID compared cloth vs medical vs no mask and concludes “as a precautionary measure, cloth masks should not be recommended.” Since with cloth masks, participants also had “significantly higher rates of ILI [Influenza like Illnesses] compared with the control [who did not use any mask].” 
During COVID, a study of over 35 European countries showed that there was no statistically significant correlation between masks and COVID infections. In addition, the study concludes, "the moderate positive correlation between mask usage and deaths in Western Europe also suggests that the universal use of masks may have had harmful unintended consequences."
More than 150 comparative studies and articles on mask ineffectiveness and harms:
Are Face Masks Effective? The Evidence:
PANDA Infobank on Masks:
The mask scam unmasked:
The CDC’s mask mandate study: debunked:
 35 studies showing mask ineffectiveness
 “This article will show that masks not only fail to protect, but also cause damage”
“Penetration of cloth masks by particles was almost 97% and medical masks 44%”
 “On the contrary, a 50% decrease has been reported after omitting face masks”
“Evidence is lacking to suggest that they confer protection from infection either to patients or to the surgeons that wear them”
 “Masks and face coverings are not effective in preventing the spread of COVID-19, even for those people who consistently wear them”
 “CDC Study Finds Overwhelming Majority Of People Getting Coronavirus Wore Masks”
 “Mask mandates and use are not associated with slower state-level COVID-19 spread during COVID-19 growth surges.”
 “No statistically significant difference between those who wore masks and those who did not”
 N95 masks are estimated to reduce oxygen intake by anywhere from 5 percent to 20 percent. That’s significant, even for a healthy person”
 “SpO2 decreases after the first hour.”
 “Ventilation, cardiopulmonary exercise capacity and comfort are reduced by surgical masks”
“Wearing a surgical mask modifies significantly and clinically dyspnea”
 “81% of them developed headaches when wearing a face mask”
 “This, in turn, reduces the immune response, negatively affects the function of the epithelial cells”
“Wearing a face mask can increase your risk of infection”
https://telegra.ph/The-mask-scam-unmasked-10-01 Source 19 & 20
 “Even masks that were never worn showed a considerable germ spectrum, since they were not sterilely packaged”
https://telegra.ph/The-mask-scam-unmasked-10-01 Source 23 & 24
 “The incidence of adverse skin reactions to the N95 mask was 95.1%”