HIV Weekly - 22nd January 2014

A round-up of the latest HIV news, for people living with HIV in the UK and beyond.

Vaccinations in people with HIV

People living with HIV are particularly encouraged to receive vaccinations against some illnesses, such as the hepatitis A and B viruses and against flu and pneumococcal disease. There are other vaccinations that are safe for people with HIV and which might be useful or necessary, perhaps because of travel plans.

It is known that, although vaccines are effective in people with HIV, their immune response to vaccines can be reduced, and sometimes a ‘booster’ dose is needed to get the full effect of the vaccine. It has not been clear, however, whether HIV has an impact on the longer-term protective effect of vaccines.

Now an analysis of studies looking at this issue has concluded that the effect of vaccinations does last less time in people with HIV than in HIV-negative people.

A clear effect on hepatitis B vaccination was noted, with only 28% of adults with HIV who had responded to the vaccination still protected by it two years after receiving it. Doubling the initial dose did not make a difference.

There were also reduced rates of protection over time for hepatitis A, tetanus and pneumococcal disease.

Reduced periods of immunity were also seen in HIV-positive children immunised against measles, polio, whooping cough and diphtheria.

As a result of their findings, the researchers have made recommendations for increased doses of, and/or monitoring antibody responses to, key vaccinations for people with HIV. They caution that many of the studies they analysed were small, so their conclusions should be explored in larger studies, as well as feeding in to vaccine research.

Read more about some common illnesses in people with HIV, including winter viral illnesses on aidsmap.  

Self-testing for HIV

In 2012, an HIV test that can be used at home was approved for use in the United States. The same test kit will become legally available in the UK from April this year.

Researchers in the US have developed a model to look at the possible impact of the home-testing kits on rates of HIV infection amongst gay men. They wanted to see if greater use of self-testing, rather than clinic-based HIV tests, had an effect on the numbers of new HIV infections.

The model assumed that clinic-based laboratory tests had a window period (the time after infection when no indicators of infection can be detected) of 15 days and would detect 100% of infections after this. The OraQuick In-Home HIV Test was assumed to have a window period of three months and to detect nearly 92% of infections.

The model was based on a city where most gay men test for HIV once or twice a year – the results will be less relevant in places where men test less often.

Results of the modelling suggest that, if HIV testing just took place in clinics, HIV prevalence would be 18.6%. However, if half of men having a test replaced clinic tests with self tests, prevalence would be over 23%. It would go up to 27.5% if all men self-tested.

This is because a number of men who are have acute HIV infection (that is, they have only recently become HIV positive) would not be diagnosed. People have a very high viral load during acute (primary) HIV infection and there is a much higher risk of HIV being transmitted.

Delays in getting HIV treatment and care for people who test positive could also cause the number of new HIV infections to increase.

The researchers recognised that there could be some situations where the use of self-testing kits could help prevent HIV transmission, such as self-testing sexual partners to avoid the risk of sexual transmission.

The opportunity for self-testing has been welcomed by HIV organisations, although there are concerns that people will not always access treatment and care services after having a positive test result. It is recommended that people who get a positive result go to an NHS sexual health clinic or a testing service to get a follow-up test. This will confirm the result and is also an opportunity to be referred to an HIV clinic for continuing health monitoring and care.

You can find more about types of HIV tests, how they are used, and testing policies and guidelines on aidsmap.com on the HIV testing topic page. Find HIV testing centres on NAM’s e-atlas or by using our HIV test finder.

Injecting drug use and hepatitis C

Across the world, injecting drug use is the most common way people become infected with the hepatitis C virus (HCV). Now a study in Canada has found that people who are diagnosed with hepatitis C are likely to reduce their injecting drug use significantly.

The researchers looked at injecting rates in a group of adults who were active injecting drug users and who did not have HCV at the start of the study. The study participants were tested for HCV every six months, and also received post-test counselling, and referrals to other services if necessary.

There was an association between being diagnosed with HCV and a reduction in injecting of heroin and cocaine, and this reduction lasted over the period of the study. The researchers see the reduced rates of injecting as a response to people being told they had hepatitis C.

During the course of the study, rates of sharing injecting equipment dropped to very low levels for all participants, whether or not they became HCV positive. 

Health monitoring and hepatitis C

Having a low lymphocyte (a type of white blood cell in the immune system) count is linked to an increased risk of infections while people are on treatment for hepatitis C, a study has found.

About 25% of people on hepatitis C treatment develop an infection at some point during the therapy. Currently, standard treatment for hepatitis C includes the drug pegylated interferon alfa. A side-effect of this drug is a reduction in the number of blood cells (cytopenia), and can result in neutropenia, a lack of one type of white blood cell.

The study observed just over 3000 people starting HCV treatment; 36% of study participants developed an infection during the research period, and 19% had moderate, severe or life-threatening illnesses.

The researchers found a strong link between having a reduced lymphocyte count because of HCV treatment and the risk of infection. They suggest doctors should monitor counts of lymphocytes and neutrophils (another type of white blood cell) carefully while people are receiving treatment for hepatitis C.

The study also found that a history of depression was linked to an increased risk of infections, as was being female. The researchers suggest doctors should be aware of the higher rates of infections in women.

Interested in hepatitis and HIV? Visit our hepatitis C topics page for more resources, feature articles and news about hepatitis and HIV co-infection. We’re also working with ELPA, the European Liver Patients Association, on a hepatitis information website for patient advocates and professionals working in hepatitis in Europe – check it out at www.infohep.org