In the Ninth chapter of Mesillas Yesharim on Zerizus (Positive Mitzvah Performance), the Ramchal explores the factors that undermine the proper performance of mitzvos. One of the undermining factors he discusses is fear. The Ramchal makes an important distinction between justified fear and excessive fear. Excessive fear creates an atmosphere which inhibits proper mitzvah performance.
In the last month or so, vaccinations have been effective in reducing the health risk of Covid. The CDC website states that if you’ve been fully vaccinated then you can gather indoors with fully vaccinated people without wearing a mask or staying 6 feet apart. They do add the caveat that you should avoid medium or large gatherings.
The difficulty with Covid is that it is travelling across the continuum from justified fear to possible excessive fear, in mostly vaccinated Shuls. There is no exact measurement to determine whether a Covid fear is excessive, and therefore different Shuls have implemented a wide range of mask policies.
Let us pray that we continue on the path of transforming our Shuls from Houses of Fear to Houses of Trust in G-d.