Covid-19: CoronaVac may offer reduced protection in HIV-positive individuals

RIO DE JANEIRO, BRAZIL – A study suggests that the protection of CoronaVac – the principal vaccine against Covid-19 in Brazil- is lower among people infected with HIV, the virus that causes AIDS. As a result, the vaccination guideline must be maintained, including priority for booster doses among this group.

Researchers at the University of São Paulo Medical School (FMUSP) compared the protection of CoronaVac in HIV-infected and non-infected people. The study showed that after being administered the CoronaVac, a person without HIV is 3.21 times more likely to develop antibodies against Covid-19 than an individual infected with the virus.

“It means that the response to the vaccine is somewhat poorer among people with HIV. It [the vaccine] is very important, but its power to generate response is lower in people with HIV compared to those without HIV,” said one of the study’s authors, USP School of Medicine professor Vivian Avelino-Silva.

Despite lower protection levels, this does not mean that people with HIV should not get vaccinated. According to the professor, the lower protection reinforces that this is a priority group and may need further strengthening of the vaccination scheme.

“It’s the kind of situation that clarifies that people with HIV should be prioritized. It suggests that perhaps people living with HIV need more boosters, earlier or in higher numbers, compared to people who don’t have HIV,” Vivian said.

The number of defense cells in the body, called CD4 cells, may help explain the difficulty in producing defenses against the novel coronavirus. People with HIV, but with higher numbers of defense cells, are twice as likely (2.26 times more likely) to develop antibodies as people in later stages of HIV infection.

The study was published as a pre-print, a type of draft in which the study remains open to review and contributions from other scientists before its final publication.

The Butantan Institute reported that two scientific studies published by researchers in Brazil and China have shown that the CoronaVac “is safe and capable of generating high levels of protection against SARS-CoV-2 in people infected with the HIV virus that causes AIDS.” One such study is the FMUSP paper, cited above.

“Four weeks after the second dose of the vaccine, the percentage of participants with positivity for neutralizing SC and NAb antibodies was high for both the group with HIV and the control group. No serious adverse reactions were reported during the study, whether among people with HIV or in the non-immunosuppressed participants,” the institute’s report reads.

Butantan adds in the report that the researchers found differences in immunogenicity parameters among people with HIV, with the group with the weakest immune system having lower immunogenicity against the Covid-19 virus when compared to those with higher defense cell counts after two vaccine doses.

“One possible approach is to use a booster vaccine dose or even administer higher antigen titers per vaccine dose,” the institute reported.