Flu Shots May Accelerate Growth of HIV, Study Finds

UCLA researchers have discovered that even mild stimulation of the immune system, such as a flu vaccination, appears to accelerate the growth of HIV.

Dr. William O’Brien and his colleagues at the UCLA AIDS Institute report in the August issue of the journal Blood that their findings suggest that severely debilitated victims of acquired immune deficiency syndrome should not be immunized with the vaccine.

They note, however, that growth of HIV is stimulated even more when an HIV-positive patient actually catches the flu virus. The team therefore recommended that most HIV patients should still get flu shots, “since actual infection with influenza virus may be more damaging.”

But patients with advanced AIDS generally don’t have a good response to the influenza vaccine “and perhaps these patients should not be vaccinated,” they said.

The team said that the growth of the virus stimulated by the flu vaccine is temporary and that the levels of virus go down after a while.

They caution that any stimulation from the environment, such as an allergy attack, can also cause the growth of HIV to increase temporarily.

“What we think may be happening is that intermittent stimulation from the environment is going to cause frequent small bursts of virus growth and that may lead to disease progression,” the team said.

The researchers studied 20 HIV patients who were given flu shots and a control group of 14 HIV patients who were not vaccinated. Those who received the shots had a tenfold increase in the production of HIV cells, while no similar increases were observed in the control group.