The COVID-19 pandemic antimaskers like to try to cite scientific sources that support their position. Of course they ignore all the other data (cherry picking) and even more often don't even bother to read the actual study and check it out.
One such study being spread around is: https://onlinelibrary.wiley.com/doi/pdf/10.1111/eci.13484
OK, so it appears to be peer-reviewed, but I'm having trouble finding the actual peer review of it. It could be because I simply can't access that part. I am not sure. Regardless I'll still check some things myself.
So let's look at the journal itself. European Journal of Clinical Investigation. The impact factor for this journal is under 3 which is rated barely as good. Above 10 is rated as excellent. It is ranked 3792. Not great, but not bad.
Ok, so let's look at the study
That study doesn't even make sense. They contradict themselves continuously with wrong information/conclusions.
For one example they state "Empirical data for the characteristics of fatalities in the later wave before mrNPIs were adopted as compared with the first wave (when mrNPIs had been used) shows that the proportion of COVID-19 deaths that occurred in nursing homes was often higher under mrNPIs rather than under less restrictive measures. This further suggest that restrictive measures do not clearly achieve protection of vulnerable populations." They cite another study as proof.
Well looking at that study ( https://www.medrxiv.org/content/10.1101/2020.11.28.20240366v1 ) they cite it states: "COVID-19 deaths that were accounted by nursing home residents decreased in the second wave, and the decrease was significant and substantial (relative risk estimates: 0.28 to 0.78) in 7/9 countries...the contribution of COVID-19 deaths in nursing home residents to total fatalities has decreased in most countries in the second wave."
They also fail in many other areas including taking in consideration things like population densities being a factor (Sweden 25/km2, England 275/km2). Also differences in elderly care are a factor. Home health care is popular in Sweden, which can be a factor compared to large LTC homes which can become problematic once an infection enters the "closes" system. One also should consider the general make-up of households in Sweden where a large proportion are single person dwelling homes which then means transmission within a bubble is reduced and contact tracing/quarantining is more efficient. Of course Sweden compared to Norway and Finland shows an very much higher spread and death rate of COVID-19.
Overall, if one does not cherry-pick, the scientific consensus is that lockdowns do help slow down the spread. It doesn't mean that they are a good idea (that's a political/economical/subjective analysis), it just means that they are effective in reducing the spread of an infectious disease.