Facebook, Instagram and YouTube have removed a video by President Jair Bolsonaro of Brazil in which he claimed that COVID-19 vaccines are linked to the development of AIDS, the Brazilian news site GloboNews and Reuters reported yesterday.

“We removed a video from Jair Bolsonaro’s channel for violating our medical disinformation policy regarding COVID-19 for alleging that vaccines don’t reduce the risk of contracting the disease and that they cause other infectious diseases,” YouTube said in a statement.

YouTube also suspended Bolsonaro for seven days, the reports added. The company previously removed other videos in which the Brazilian leader, who had mild COVID-19 in July, recommended using hydroxychloroquine and ivermectin, medications that have not been proved effective for treating the disease.

According to GloboNews, Bolsonaro’s claim was based on a rumor circulated on social media and published by a conspiracy website stating that official reports from the United Kingdom had shown that people vaccinated against COVID-19 are developing AIDS faster than expected—purportedly because the vaccines progressively weaken immune response. The U.K. Department of Health and Welfare told GloboNews that this is not true and stressed that AIDS is caused by HIV, not vaccines.

The Brazilian Society of Immunology issued a statement saying that “no vaccine developed against COVID-19 can cause AIDS and neither can any vaccine have the potential to transmit the HIV virus.” (The one exception could be if needles for vaccine injections are reused on more than one person.) In another statement, the Brazilian Society of Infectology concurred, advising that people living with HIV/AIDS should be completely vaccinated, including a booster dose if appropriate.

As discussed on social media and summarized by the Questão de Ciência Institute (a Brazilian organization devoted to correcting scientific misinformation), the idea that COVID-19 vaccines are associated with increased HIV risk may have arisen from a pair of failed HIV vaccine studies.

In the STEP and Phambili trials, people who received a Merck vaccine based on an adenovirus type 5 (Ad5) vector were more likely to acquire HIV. The greater risk was particularly seen in uncircumcised men who were previously infected with this adenovirus, which causes the common cold. In light of these findings, the National Institute of Allergy and Infectious Diseases held a summit in 2013 to discuss the safety of adenovirus vector vaccines for people at risk for HIV, as the Treatment Action Group reported. The reasons for the elevated risk remain unclear, but it may be related to the increased presence of T cells susceptible to HIV infection.

A similar risk increase was not seen in another trial of the Ad5 HIV vaccine nor in studies of experimental HIV vaccines using the less common adenovirus type 26 (Ad26) as a vector. One large trial of an Ad26 HIV vaccine was recently shut down after it became clear that the vaccine was not effective, but there were no safety concerns.

While the Ad5 HIV vaccine candidate was scrapped, prominent vaccine researchers raised concerns last year in The Lancet about using the same adenovirus vector for COVID-19 vaccines. “If I were in a sub-Saharan African country and making a decision as to what I would want for my country for a general population use of a SARS-CoV-2 vaccine, I don’t see why I would pick an Ad5 vector [vaccine] when there are many other alternative choices,” coauthor Lawrence Corey, MD, of the Fred Hutchinson Cancer Research Institute, told Science magazine.

The Chinese CanSino COVID-19 vaccine uses the Ad5 vector, and the Russian Sputnik V vaccine uses both Ad5 and Ad26. The Johnson & Johnson vaccine uses Ad26 only. The AstraZeneca-Oxford COVID-19 vaccine uses a chimpanzee adenovirus. The Pfizer-BioNTech and Moderna messenger RNA (mRNA) vaccines do not use adenovirus vectors.

Given these concerns, authorities in South Africa—where HIV incidence is high—this month declined to authorize the Sputnik V vaccine, and Namibia recently suspended its use.

Completely unrelated, an experimental Australian COVID-19 vaccine was discontinued last year after recipients produced antibodies against an HIV protein fragment used to stabilize the SARS-CoV-2 spike protein—the vaccine’s intended target. Study participants were not actually infected with HIV, and they did not develop AIDS, but they tested positive for HIV antibodies, which could create problems for HIV screening efforts if the vaccine was widely used.

The bottom line is that none of the available COVID-19 vaccines have ever been linked to increased risk of HIV acquisition or progression to AIDS in clinical trials or in real-world use. 

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Click here for a POZ feature on the state of HIV vaccine research.