Researchers from King’s College, London and the Francis Crick Institute undertook a real-world study on 205 cancer patients and found that a single dose of the Pfizer-BioNTech COVID-19 vaccine protected 39% of persons with cancer when compared with 97% of those who had no cancer related diseases.

The researchers concluded that a 12-week wait for the second dose could increase vulnerability to the coronavirus among these patients. Although this study is not peer reviewed, it has brought up a few relevant issues.

The study consisted of 151 people with cancer and 54 were in the control group. The results showed that cancer patients, who received the second dose of the Pfizer vaccine in the three week time recommended by Pfizer, had a better immune response. 95% of the persons with solid tumors had detectable antibodies.

The team said that the recent decision to leave up to a 12-week gap between the first and second dose, which is currently occurring in the U.K., is increasing the vulnerability of cancer patients to COVID-19.

Cancer Research U.K. has commented that the study group was relatively small and that people should continue to follow their doctor’s advice.

A Department of Health and Social Care spokesman said that they are focused on saving lives and that the antibody response is only part of the protection that the vaccine provides.

It said that the independent Joint Committee on Vaccination and Immunization advises the government on vaccine use and prioritization; reviews data and evidence on vaccine efficacy and effectiveness.

Although the real world study on cancer patients is small and not peer reviewed, it has highlighted the importance of following a three week gap between two doses of the Pfizer vaccine instead of the current up to 12 week gap between the first and second dose; to get a good immune response COVID-19.