[7] On 24 August, Minister Ruiz confirmed the participation of Colombian volunteers in the Phase III trials of the Ad26.COV2.S vaccine, developed by Janssen Pharmaceuticals.
[8] On 7 October, the Phase III clinical trials of the vaccine developed by Janssen Pharmaceutica began, with the application of the first dose to a volunteer in Floridablanca.
In the first phase, the objective was reducing mortality and severe case incidence rates from COVID-19, as well as protecting health workers.
Workers of health care companies (EPS) and those who work in control bodies and different organizations that assist, accompany and validate the process of management of the pandemic were prioritized in Stage 2, while people with additional comorbidities such as AIDS, cancer, tuberculosis, obesity and others were included in Stage 3 along with the population aged 50–59.
[28] As planned, intensive care nurse Verónica Machado was the first to be vaccinated on the morning of 17 February, under widespread media coverage.
Duque said that this first batch of vaccines would be destined for front-line health and support personnel, while also confirming that the Colombian government expected the arrival of 1,600,000 additional doses within the following 30 days.
Those three departments border Brazil, and the Colombian government's intent was to epidemiologically "blockade" the Brazilian variant and prevent its arrival in other areas of the country.
This exceptional measure did not cover pregnant women nor people with a COVID-19 positive test result earlier than 90 days.
[41] (The Pfizer vaccine was also effective against the Gamma variant, according to a study published 8 March in the New England Journal of Medicine.
The former health minister Gabriel Riveros acknowledged that the vaccination program remained limited by this relatively low number.
At the same time, the Ministry of Health also requested to extend the interval of the Moderna vaccine (made under the same technology as the Pfizer one) to 84 days.
[51] On 16 September 2021, the Ministry of Health issued new guidelines for vaccine rollout, aiming to achieve the goal of 35 million people immunized by 31 December 2021:[52] On 16 September 2021, accompanying updates to the national vaccination plan, the Ministry of Health approved booster doses for people aged over 70.
[56] The rollout began with people over 70 because this age group has lower immune capacity and higher mortality rates, and for them a third dose can be especially protective.
[60] Polls conducted between January and March 2021 in 23 cities, as analyzed by the Dane found that 76% of men and 70% of women wanted to be vaccinated.
[61] On 6 May 2022, President Duque celebrated having achieved the original goal of vaccinating 70% of the Colombian population, or 35.7 million people.