News Scan for Oct 08, 2013

News brief

GSK reports malaria vaccine follow-up, eyes regulatory application

At a malaria conference in South Africa today, researchers reported more promising findings for a vaccine that is furthest along in development, and GlaxoSmithKline (GSK) officials said they now intend to submit a regulatory application for it to the European Medicines Agency (EMA) in 2014, according to a company press release.

The study is the latest phase 3 trial of the RTS,S malaria vaccine candidate, which contains an AS01 adjuvant. The most recent phase of the ongoing studies, which have included more than 15,000 children from seven African nations, focuses on the vaccine in young infants and assesses protection for 18 months. According to GSK, the vaccine halved the number of malaria cases in children aged 5 to 17 months at first vaccination, and it reduced by a quarter the number of infections in infants 6 to 12 weeks old at first vaccination.

Vaccine efficacy declined over time but was statistically significant at all sites in young children and at four sites in infants. GSK said that over the 18-month follow-up the vaccine continued to show an acceptable safety and tolerability profile. The company said it will continue to closely monitor a previously reported meningitis signal during the rest of the trial. A report on 32-month follow-up and the impact of a fourth booster dose is expected in 2014.

Andrew Witty, chief executive officer of GSK, said that though researchers have seen a decline in efficacy over time, the number of children affected by malaria means that the vaccine can help prevent a large number of cases. "These data support our decision to submit a regulatory application for the vaccine which, if successful, would bring us a step closer to having an additional tool to fight this deadly disease," he stated.

The company said the World Health Organization (WHO) has signaled that if the EMA gives a positive opinion and if additional phase 3 studies show the vaccine is safe and effective, it may make a policy recommendation that could pave the way for large-scale implementation in African countries.

The WHO said in background information on malaria vaccine development that the vaccine would be evaluated as an addition to, not a replacement for, existing preventive, diagnostic, and treatment measures.
Oct 8 GSK press release
WHO malaria vaccines
Oct 18, 2011, CIDRAP News story "Study: malaria vaccine halved cases in young kids"


New York City unveils new plan to battle hepatitis C

The nearly 150,000 people in New York City who have chronic hepatitis C, half of them unaware of their infection, are in for "a very hopeful time," said New York Health Commissioner Thomas Farley in a press release yesterday announcing a new action plan to ensure they are all evaluated for treatment.

The disease, which may have few or no symptoms until life-threatening complications such as liver cancer or end-stage liver disease develop decades after initial infection, has since 2007 caused more deaths in the United States than HIV, says the release from the New York City Department of Health and Mental Hygiene (DOHMH).

The new plan, titled Hepatitis in New York City: State of the Epidemic and Action Plan, states that about 146,000 New Yorkers have chronic hepatitis C virus (HCV) infection, the majority living in neighborhoods with high rates of poverty. Even when the disease is diagnosed, many HCV patients receive no treatment, in part because few healthcare providers are sufficiently knowledgeable about management, the DOHMH said.

The action plan spells out seven public health objectives that DOHMH will undertake to help improve the situation:

  • Enhance public awareness of HCV
  • Enhance provider awareness and capacity to provide HCV management and treatment
  • Promote HCV testing
  • Enhance HCV surveillance
  • Improve linkage between HCV-infected persons and sources of care
  • Promote HCV prevention
  • Collaborate with other organizations to develop, promote, and advance policies and regulations to support goals of the new strategy

HCV is spread when blood from an infected person enters the body of someone else. Certain behaviors, such as injection drug use, are risk factors. "After many years in which the infection was very difficult to treat, hepatitis C can now be cured," said Farley in the release.
Oct 7 press release about the plan
Full text of plan (pdf—52 pages)


Study spells out benefits of second varicella vaccine dose

A study to measure the impact of adding a second dose of varicella vaccine to childhood immunization schedules found that illnesses, outbreaks, and hospitalizations dropped in the 5 years following the change.

The analysis covered two communities, Antelope Valley, Calif., and West Philadelphia, Pa. The research team included health officials from the two states, plus the US Centers for Disease Control and Prevention (CDC). The findings were published yesterday in an early online edition of Pediatrics.

The study looked at varicella incidence, severity, and outbreaks in the two regions from 1995 to 2010. Federal vaccine advisors recommended the second dose in 2006 after observing that while disease activity steeply declined after the vaccine was introduced, outbreaks still continued to occur, even in school populations that had high vaccine coverage.

Between 2006 and 2010 the team saw a 76% drop in infections in Antelope Valley and a 67% decline in West Philadelphia. For both sites the decline since 1995 was 98%. The group saw declines across all age-groups, even in babies too young to be vaccinated. Hospitalization rates fell by more than 40% after the second dose was recommended.

Researchers concluded that the findings show the benefits of high levels of immunity in the population.
Oct 7 Pediatrics abstract


Vaccines provide suboptimal protection against H5N1 in ducks

Two commercial H5N1 avian flu vaccines widely used in poultry in Vietnam were found to provide inadequate protection in domestic ducks in a study to appear in the Oct 9 issue of Vaccine, demonstrating that routine monitoring of vaccine efficacy is necessary.

The researchers, from the United States and Vietnam, tested the Re-1 vaccine, containing A/goose/Guangdong/1/1996 hemagglutinin (HA) clade 0 antigens, and Re-5, containing A/duck/Anhui/1/2006 HA clades 2.3.4 antigens. Ducks received one of the vaccines at age 7 days and again at 14 or 21 days. At 30 days of age they were challenged with H5N1 viruses isolated between 2008 and 2011 in Vietnam.

Re-1 was effective against HA clades 1.1 and viruses isolated in 2008, with no virus shedding after challenge. Both vaccines were 90% to 100% protective against the 2010 HA clade virus, but the ducks shed the virus for 7 days after challenge.

Both vaccines gave partial protection against HA clades and viruses isolated in 2011, but a high proportion shed the viruses for 10 days after challenge, and the ducks given Re-1 and challenged with the virus had a 50% mortality rate. All of the viruses used in the challenge caused severe clinical signs and mortality in unvaccinated control ducks, with the exception of one 2011 virus.

When the HA gene sequences of the two vaccines were compared with those from the challenge viruses, more differences were found in the 2011 viruses than in the 2008 and 2010 viruses. This correlates with the poorer vaccine protection against the 2011 viruses and demonstrates the importance of ongoing vaccine efficacy testing in view of the increasingly divergent H5N1 viruses circulating, the authors wrote.
Oct 9 Vaccine study abstract

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