A retrospective study published in JAMA concluded that the BNT162b2 vaccine from Pfizer (NYSE:PFE) and BioNTech (NSDQ:BNTX) offered statistically significant protection against SARS-CoV-2 infection. The pivotal trial Pfizer used to win emergency use authorization for the vaccine excluded pregnant women. COVID-19, however, increases the risk of pregnancy-related complications — particularly in the third trimester. To determine how…