A claim is circulating, particularly across social media, that Vaccine-acquired immunodeficiency syndrome (or Vaccine-AIDS or VAIDS), which is falsely claimed to be a condition similar to AIDS, is caused by the COVID-19 vaccines and boosters. Vaccine-AIDS is not a known medical condition. Any such claim that VAIDS as it relates to COVID-19 vaccines or booster shots is unproven.

AIDS or Acquired Immunodeficiency Syndrome is caused by a virus called HIV (Human Immunodeficiency Virus). HIV is the virus that can cause infection, whereas AIDS is a condition caused by HIV; not all people who get infected with HIV will go on to have AIDS. Someone AIDS, also known as stage 3 of HIV, develops when an HIV infection gets severe enough that it starts damaging the immune system.

Some other known ways of acquiring immunodeficiency (also called secondary immunodeficiency disorder) include chronic conditions like cancer, malnutrition, environmental toxins, certain drugs, and genetic disorders.

Research has shown that protection from a COVID-19 vaccine (two doses in the case of some vaccines) reduces over time, which is why after studying the effects of a booster dose, it is now recommended, especially for those who are immunocompromised. Studies show that vaccine efficacy following a third booster dose increased back to over 90% against Delta and Omicron variants in reducing hospitalizations.

Reduced effectiveness of a vaccine does not mean that it is causing people immunodeficiency disorders. Millions of people have been vaccinated and the vaccines are continuously monitored for their effectiveness. So far, there is no evidence to prove this claim.

False claims have been circulating that COVID-19 vaccines and boosters cause “VAIDS” or “vaccine-acquired immunodeficiency syndrome.” Not only is this information false but there is no known medical condition called VAIDS. This claim was first made for COVID-19 vaccines in general and is now being circulated for booster shots.

There are a number of places that this claim may have stemmed from. One place this claim may have stemmed from is from legitimate concerns that some scientists have about COVID-19 vaccines made with a recombinant adenovirus type-5 (Ad5) vector potentially increasing susceptibility to an HIV infection.

These concerns stem from two studies that researched the efficacy of an Ad5 vectored vaccine in preventing HIV infection. The researchers of both studies found an increased risk of HIV among vaccinated men. These results have led some experts to caution against the deployment of vaccines that use similar vectors. These experts are especially concerned about the use of such vaccines in areas where there is already high HIV prevalence out of concern that the vaccines could lead to more HIV cases.

These concerns are legitimate, but there are a few reasons that they don’t apply to the WHO-approved vaccines being rolled out:

1. Most importantly, none of the WHO-approved vaccines use an Ad5 vector. Three of the vaccines are using adenoviruses, but not Ad5. Those three are the AstraZeneca vaccine, the Johnson & Johnson vaccine, and the Covishield vaccine (Oxford/ AstraZeneca formulation). Other types of adenovirus vaccines have not been shown to increase risk of HIV or any other immunodeficiency risk.

2. It is unclear if the same increase in HIV risk would be the same with a COVID-19 vaccine.

3. Related to point two, the vaccines that led to increase in HIV risk did not have an “HIV envelope” – which is the outside coat of HIV made of fats. HIV uses protein "spikes" embedded in its envelope to enter host cells. HIV vaccine studies that did have an HIV envelope did not lead to an increase in HIV risk. As a result, not only is it possible that this increased HIV risk may only occur with HIV-specific vaccines, but it’s also possible that this HIV risk may only occur with HIV-specific vaccines that use the HIV envelope.

Sputnik V and CanSino’s Convidicea COVID-19 vaccines both use Ad5. Neither of these are WHO-approved vaccines but they are being rolled out in multiple countries. There is no current data showing increased HIV risk with these two vaccines; however, South Africa, a country with high HIV rates, has not approved either of these vaccines due to concerns.

These very specific concerns – that do not apply to any WHO-approved vaccines or the majority of COVID-19 vaccines, and might not end up being real concerns for the two vaccines that use Ad5 – are likely one of the reasons that false claims have started circulating that COVID-19 vaccines can cause HIV, AIDS, or VAIDS (a fake condition).