Dynamics of the level of anti-SARS antibodies within a year after three vaccinations of patients with prostate cancer

Cancer patients are a group particularly vulnerable to various infections, including SARS-CoV-2. Men are more susceptible to severe COVID-19, with a higher mortality rate. Many researchers have shown that immunity after two doses of the vaccine wanes over time, and a third booster dose is necessary to increase protection. Therefore, we undertook to assess the dynamics of anti-SARS-CoV-2 antibodies within a year after three doses of Pfizer-BioNTech vaccine in Polish men with prostate cancer. For this purpose, the titer of anti-SARS-CoV-2 antibodies was examined 3, 6, 9, and 12 months after the third dose of the vaccine. We also analyzed whether the decline in antibody titer depends on the tumor stage (Gleason Score, T stage). The obtained results indicate that the level of anti-SARS-CoV-2 antibody is significantly lower in PCa patients compared to the controls. Twelve months after the third vaccine dose, the seroprevalence among prostate cancer patients was 53.3% (50-59) and 29.8% (60-78), respectively. In the period from 3 to 6 months, as well as from 6 to 9 months after vaccination, a statistically significant decrease in antibody titer was observed in both analyzed age groups. Moreover, their levels were lower in more advanced clinical stages. Conclusion: Due to the fact that in the following months the antibody titer decreased much faster in PCa patients than in people from the healthy control group, it seems reasonable to ask whether PCa patients should be vaccinated with a booster dose more often than once a year.