No COVID-19 cases in cancer patients 1-year post-vax

There are no COVID-19 cases documented in patients with solid tumours at 1-year post-vaccination with the BNT162b2 vaccine as shown in a prospective study from Israel.

Durable cellular and humoral responses to the vaccine were observed in these patients.

“This analysis was a follow-up report in those with solid tumours who had been receiving active treatment at first vaccination … We’ve found that the BNT162b2 vaccine exerts a cellular and humoral sustainable response that is manifested by a low infectivity rate,” said lead author Dr Ithai Waldhorn from the Division of Oncology, Rambam Health Care Campus, Haifa, Israel.

The majority had metastatic disease

Humoral response has been extensively studied in patients with cancer, but there is scarcity of data regarding cellular immunity and its association with vaccine efficacy, noted Waldhorn.

The researchers prospectively explored cellular and humoral pathways at 6 months post-vaccination in cancer patients receiving active antineoplastic treatment, as well as a subset of patients following receipt of a booster dose. [JAMA Oncol 2022;doi:10.1001/jamaoncol.2022.1467]

One hundred sixty-nine patients (mean age 66 years, 57 percent male) with solid tumours (81 percent with metastatic disease) were included in the study. The most common cancers were gastrointestinal (33 percent), lung (23 percent), breast (17 percent), and genitourinary (12 percent).

All were receiving treatment for cancer at the time of the first vaccination – chemotherapy (57 percent), a biological agent (36 percent), immunotherapy (37 percent), or combination treatment.

Serum samples and peripheral blood mononuclear cells were collected at 6months postvaccination for the entire cohort and additionally after receipt of a booster dose in a subset of patients (22 percent). Humoral responses at 6 months were analysed using an  S1/S2 immunoglobulin G assay. T-cell responses were assessed using an ELISA assay. At 1 year, the patients’ COVID status was evaluated.

Chemo associated with humoral response

Patient age, sex, and tumour type did not predict cellular response to vaccination. Chemotherapy was associated with humoral response, but there was no association between spot-forming units (SFUs) and treatment type. 

The serological response was significantly associated with cellular response. However, five of the patients who were seronegative had SFU levels that were equal to or greater than the mean SFU level of the seropositive patients.

After receiving a booster dose, 67 percent of the patients had a significant increase in cellular immune response (p=0.02), and 100 percent had an increase in antibody levels (p<0.001).

Patients with cancer are prone to COVID-19. “That no one developed COVID-19 infection at 1 year after vaccination suggests protection in this population,” said Waldhorn.

The findings further characterized cellular and humoral responses to the BNT162b2 vaccine following vaccination. “The more data we have that characterize vaccine responses in individual cancer populations, the better we can advise patients,” commented Dr Steven Pergam of the Fred Hutchinson Cancer Research Center in Seattle, Washington, US, and head of the committee that developed the National Comprehensive Cancer Network COVID-19 Vaccination Guide for People With Cancer.