A published, peer reviewed study that demonstrated the benefits of facial coverings (not specific to professionally fitted N95 respirators) at reducing the odds of becoming infected after exposure to an infected person.
Predictors of Severe Acute Respiratory Syndrome Coronavirus 2 Infection Following High-Risk ExposureClinical Infectious Diseases, 2021Benefits of mask usage were greatest among unvaccinated and partially-vaccinated participants, and in interactions involving non-household contacts or interactions occurring without physical contact.
I view mask use in the same light as social distancing, I use the mask in crowded indoor locations when there is elevated community transmission. Like vaccines or social distancing, it is not 100% effective, but it reduces the risk of infection and can be additive to the other protections.
As the pandemic has continued, science has progressed and become more nuanced about immunity to this evolving virus. Immunity is no longer viewed solely by the measured level of antibodies circulating in the body but now also includes the breadth of circulating antibodies (their targets: specific parts of the RBD, spike, nucleocapsid, and their susceptibility to genetic variation in the virus) and the breadth of antibodies produced by memory cells. Studies have found that repeated exposure to the virus (or parts of the virus in the form of vaccines) increases the breadth of antibodies and breadth of memory cells and therefore future protection to new genetic variants. While circulating antibody levels (from infection or vaccination) may wane, immunity may continue.
It is difficult to know if the virus is really done with us as long as it continues to evolve within those it continues to infect and within the animals we are now learning it also infects (example: white-tailed deer). I for one will enjoy this time of much lower community transmission (where I live) but I will continue to monitor it and be ready to adjust my behaviors to limit my risk of exposure and then potential transmission to higher risk family and friends.
