The majority of US adults at risk of hepatitis B remain
unvaccinated against the potentially life-threatening infection of hepatitis, according to
research published in advance of print in the online edition of Infection.
The research highlighted missed opportunities for
vaccination, especially for individuals who had received health care while in
prison. The authors express concern that hepatitis vaccination programmes targeted at
adults are seriously underfunded.
“In 2005, a total of only 4.5% of the $234,897,000 funds
appropriated for the purchase of vaccines was used for adult populations,
yielding a funding shortfall of approximately $160 million. This translates
into a substantial proportion of uninsured adults being unable to access
recommended immunization services through federally funded vaccination
Separate research conducted in Barcelona and published in BMC Infectious Diseases showed that hepatitis
A vaccination efforts were not preventing periodic outbreaks of the infection
among gay men.
A highly effective vaccine against hepatitis B has been
available since the early 1980s. Nevertheless, incidence of the infection in
the US remains high, with approximately 80,000 new diagnoses each year.
Approximately 75% of newly reported hepatitis B infections
are in specific high-risk groups. These include injecting drug users, gay and
other men who have sex with men, people with a history of sexually
transmitted infections or high numbers of sex partners, and healthcare
workers. With the exception of the latter, vaccination rates in these high-risk
groups are low.
US investigators used results from the 2007 Behavioral Risk
Factor Surveillance Survey (BRFSS) to assess rates of hepatitis B vaccination
in high-risk groups and to see if opportunities for vaccination had been
The BRFSS is a telephone survey which includes a
representative sample of the US population. A total of 15,432 high-risk
individuals were included in the present analysis.
Over half (56%) reported that they had not been vaccinated
against hepatitis B.
Higher rates of vaccination were seen in those aged under 33
years than in individuals aged over 33 (61 vs 33%). A smaller proportion of
individuals who were in a relationship were vaccinated compared to those who
reported not being in a relationship (44 vs 51%).
Use of healthcare was also associated with the likelihood of
hepatitis B vaccination. Higher rates were seen in individuals who had been
vaccinated against influenza and pneumonia than in patients who had not been
immunised against these infections (57 and 61% vs 45 and 44%).
Rates of vaccination were also related to healthcare
provider. Two-thirds of individuals who reported being tested for HIV by a
private doctor had been vaccinated against hepatitis B, as had 60% of
individuals who were tested for HIV at a hospital, 51% tested at a clinic, and
50% at a counselling and testing site.
In contrast, 71% of individuals who had had an HIV test in
prison remained unvaccinated against hepatitis B, as did 66% of individuals
screened for HIV at a drug treatment facility.
Multivariate analysis confirmed the association between the
receipt of immunisations against pneumonia (OR = 2.27; 95% CI, 1.80-2.87) and
influenza (OR = 1.68; 95% CI, 1.39-2.03) and an increased likelihood of
hepatitis B vaccination.
“One could posit that patient who reported receiving the
influenza and/or pneumonia vaccine have a heightened awareness of the utility
and importance of vaccines in disease prevention and therefore were more likely
to accept or request a vaccine against hepatitis B,” suggest the authors.
Patients who reported being unable to see a doctor because
of concerns about cost were 33% less likely to be vaccinated against hepatitis
B (OR = 0.77; 95% CI, 0.60-0.98).
“High costs associated with this vaccine may discourage
uptake in this population,” write the investigators.
HIV testing location was also confirmed as a predictor of
vaccination. Individuals tested in the correctional facility had their chances
of being vaccinated reduced by 40%.
opportunities for hepatitis B vaccination continue to occur in vaccine delivery
settings frequented by high-risk adults, such as prisons and jails and drug
treatment centres,” note the reseachers
They conclude, “the results of this study…underscore the
inadequacy of vaccination coverage in high-risk individuals and highlight areas
of opportunity to bridge gaps in vaccination coverage.”
A separate study showed that current vaccination efforts are
failing to prevent outbreaks of hepatitis A in gay men in Barcelona.
Gay and other men who have sex with men are a known risk
group for hepatitis A.
A vaccine that provides a high level of protection against
hepatitis A is available. Since 1994 health authorities in Barcelona have
recommended that all gay men should receive this immunisation. Starting in
1998, a combined hepatitis A and hepatitis B vaccine has been provided to all
twelve year-olds in the city. In 2004 an outreach programme was launched
offering the vaccine and other sexual health services at gay saunas in the city.
Investigators wished to see if vaccination efforts were
having an impact of on incidence of hepatitis A in Barcelona generally and in
gay men specifically.
Incidence of the infection between 1989 and 2010 was
This showed that the median annual incidence of hepatitis A
was 4.7 per 100,000 females and 11.7 per 100,000 males. Over the period of the
study, incidence of hepatitis A fell significantly in females (p = 0.002) but
remained steady in men.
Three large outbreaks of hepatitis A were identified in gay
men. These occurred between January and December 2002, from mid 2003 to mid
2004, and from September 2008 to June 2009.
The mean age of individuals diagnosed with the infection was
between 31 and 33 years. A significant and unchanging proportion of men were
HIV-positive (21 to 28%).
In 2002 outbreak, 44% of cases were in men who reported
using saunas. This had fallen to 19% in the 2008-2009 outbreak (p = 0.0001).
The investigators believe this shows that their vaccination outreach programme in
saunas was successful.
The proportion of cases involving sex workers also fell from
7 to 0%.
Almost a fifth of patients reported recent travel to another
industrialised country in the six weeks before their diagnosis with hepatitis
A. Circulating genotypes of the infection were similar to those seen in London and
other European cities.
“MSM present consistently high incidence without appearing
to decrease,” conclude the investigators. “Prevention interventions which
effectively reach the whole MSM community are needed.”