Pregnant and lactating mothers have historically been excluded from clinical trials. To understand the shift from excluding to including this population in COVID-19 vaccine trials, we conducted a review of guidance issued by countries in southern Africa over the last three years. We conducted a review of documents and official statements recorded on Ministries of Health websites, and social media platforms, the World Health Organisation website, the COVID-19 Maternal Immunisation tracker and the African Union official webpage. Search terms included COVID-19 vaccination policies, guidelines for pregnant and lactating women, COVID-19 vaccination trials and pregnant women. We retrieved and reviewed policies, guidelines, and official statements from 12 countries. We found inconsistencies and incomplete guidance in respect to the inclusion of pregnant and lactating mothers in COVID-19 vaccine trials from the selected countries. Of the twelve countries reviewed, Namibia and South Africa had clear guidance on vaccination plans and implementation for pregnant women, and their inclusion in COVID-19 vaccine trials. Explicit and clear guidelines are critical in communicating changes in policy towards those deemed vulnerable for them to participate in vaccine trials. This review provides lessons for future pandemics on managing changes in guidance towards those groups historically excluded from vaccine and clinical trials.