Does flu vaccine provide adequate and better protection for people with HIV. Yes, if the results of a study carried out in the
is any indication. United States
A research study in the
has found that quadruple-dose flu vaccine for the elderly can be used for providing better protection for people with HIV. US
The study was part of a programme to find out results of research involving high-dose vaccine injected into people who have compromised or reduced immune systems.
The team of researchers were from
Philadelphia institutions and they are now asking a federal advisory committee in the to recommend high-dose vaccination for HIV-positive people. US
Incidentally, the Food and Drug Administration (FDA) in late 2009 had licensed Fluzone High-Dose, manufactured by Sanofi Pasteur in
, for use in people aged 65 and older. Swiftwater, Pa.
There was limited research on other groups, such as people with HIV.
The elderly and people with compromised immune systems account for the vast majority of the thousands of deaths from seasonal influenza in the
. Such people suffer from decreased immune levels and they are prone to severe complications. Such people also produce a weaker response to standard vaccine, making them more likely to catch flu. US
The study found a higher dose of vaccine more immunogenic, and more surprisingly the stronger immune response was found in people with HIV. This proved to be similar to that produced by older people with Fluzone High-Dose. It also matched the response in healthy younger adults to the standard vaccines.
Medical experts and researchers have been trying to devise ways to give better protection from the flu to people with HIV, cancer, rheumatoid arthritis, renal failure and other diseases wherein treatment suppresses the immune system.
Philadelphia study was led by Noah McKittrick, then at Penn and now at . It involved researchers at Penn and also at Thomas Jefferson University . Drexel University
Under the study, 190 HIV positive adults were enrolled at Penn's MacGregor Clinic during the 2010-11 flu season. The trials were conducted between October 27, 2010 to March 27, 2011. Half the enrolled got a high dose (60mcg); the other half the standard version of Fluzone (15 mcg of antigen per strain).
The high-dose group produced more antibodies than the standard group against all three influenza. Both groups had started the season with relatively high levels of protection.
More than 90 per cent of high-dose group produced immune responses considered protective against each of the three strains. No serious adverse events or side effects were reported. An increase in minor reactions, such as pain at the injection site, was similar to that seen in the elderly.
Now the question is whether the vaccine will actually prevent the flu. This study actually measured the level of antibodies to protect against the flu - not the flu itself- and therefore studies on prevention would require more studies.
What were the actual results of the study.
In all, 195 participants had enrolled and of them 190 completed the study (93 in the standard-dose group and 97 in the high-dose group).
The seroprotection rates after vaccination were higher in the high-dose group for the H1N1 (96 per cent versus 87 percent treatment difference, 9 percentage points [95 per cent CI, 1 to 17 percentage points]; P = 0.029), H3N2 (96 per cent versus 92 per cent treatment difference, 3 percentage points [CI, -3 to 10 percentage points]; P = 0.32), and influenza B (91 per cent vs. 80 per cent treatment difference, 11 percentage points [CI, 1 to 21 percentage points]; P = 0.030) strains. Both vaccines were well-tolerated, with myalgia (19 per cent), malaise (14 per cent, and local pain (10 per cent) the most frequent adverse events.
The main limitation of the study was that the effectiveness of the vaccine in preventing clinical influenza was not evaluated. The number of participants with CD4 counts less than 0.200 × 109 cells/L was also limited.Moreover, the objective of the study was to compare the immunogenicity of high-dose influenza vaccine with that of standard dosing in HIV-positive participants and the participants included those over 18 year of age who were HIV infected.