evidence: Several studies have shown that booster doses are effective in people with HIV and other immunocompromised people, leading to substantial increases in antibody levels. A large US study that covered the period when the Delta and Omicron variants were circulating in the United States showed that immunocompromised people – including people living with HIV – who received a third vaccine dose were significantly less likely to be admitted to hospital with severe COVID-19 or experience a breakthrough infection when compared to immunocompromised people who had been vaccinated without boosting (Sun). An Israeli study of the effects of a fourth vaccine dose showed that by the sixth week after receiving this fourth dose, recipients were 77% less likely to develop severe COVID-19 disease than people of the same age who had only received three doses (Bar-On). [...] - COVID-19 vaccines are safe in people with HIV. There is no evidence that people with HIV have a higher rate of side effects after vaccination or unusual side effects. There is no evidence that any COVID-19 vaccine interacts with HIV treatment or causes HIV viral load to increase. - COVID-19 vaccines are effective in most people with HIV. They stimulate strong antibody responses in people with HIV with higher CD4 counts. People with lower CD4 counts (below 200) have weaker responses to vaccination and their antibody responses after vaccination may dwindle faster than those of people with higher CD4 counts.