Meningitis B tests raise hope of vaccine

[Al-khiyal]

Meningitis B tests raise hope of vaccine

May 15, 2008 -- A vaccine against one of the most feared childhood diseases, meningitis B, looked a little closer yesterday after scientists revealed that a second stage of trials, in babies, had been successful.

Parents are warned by medical staff to look out for the tell-tale signs of meningitis B - in particular a rash that does not disappear when the skin is pressed down with a glass. Within 24 hours a child can become severely ill and without the right antibiotics might die. Children are now routinely immunised against meningitis C, which used to be the most lethal form of the disease, and the Hib and pneumococcal vaccines prevent other strains. But so far meningitis B, a bacterial strain, has eluded efforts.

Yesterday, doctors involved in the development of a possible vaccine by the Swiss company Novartis told a meeting in Graz, Austria, they had successfully concluded phase II trials in 150 babies in the UK and had moved on to large-scale trials that will show whether the vaccine is protective in everyday life.

"The prospect of one vaccine that protects infants worldwide against meningococcal serogroup B would be a key achievement in global disease prevention of our time," said Dr Ray Borrow, head of the vaccine evaluation department at Manchester Royal Infirmary, who helped organise the study, which took place in the UK.

The babies were injected with the new vaccine at two, four and six months of age, with a booster at 12 months. Blood samples were taken a month after the third dose and again a month after the booster. Antibodies showed the children had developed good immune responses against certain strains of meningitis B bacteria. The phase III trial will involve immunising thousands of babies to see if the vaccine protects in real life when babies are in contact with the disease. Scientists will want to know whether the vaccine protects against more strains of meningitis B than those specifically included.

"The problem with producing a vaccine against meningitis B is that there are so many different strains," said Dr Andrew Pollard, head of the Oxford Vaccine Group at the University of Oxford, who helped run the study. "These initial results show that the vaccine induces an immune response against strains containing the vaccine components. The next step is to find how broad these responses are against other strains. There is still a long way to go, but a vaccine that gave broad protection against meningitis B would be hugely significant."

There are more than 1,000 cases of group B invasive meningococcal infections each year in the UK, usually in babies and young people. The bacteria either affect the membranes around the brain and spinal cord or get into the blood stream, causing septicaemia. Death can occur in 24 hours, and does so in 10% of cases, while 20% suffer damage.

Christopher Head, chief executive of the Meningitis Research Foundation, said the results were encouraging. "Meningitis and septicaemia remain diseases which continue to threaten the health and lives of people throughout the world."

Harriet Penning of the Meningitis Trust said: "It is at an early stage and there is a long way to go, but this is potentially huge."

[Al-khiyal]

Meningitis: defeated at last?

May 15, 2008 -- The annual scourge of deaths and severe illness caused by meningitis could be consigned to the history books after scientists announced startling results from trials of a potential vaccine.

In the most significant advance in a decade, researchers say they have obtained powerful immune responses in 150 British infants on whom the vaccine was tested, suggesting it would be protective against the group B type of the disease.

An effective vaccine against meningitis B is the holy grail of meningitis research and could virtually eliminate the devastating bacterial infection from Britain and other European countries. Vaccines against group C meningitis, which was introduced in 1999, and Hib meningitis in 1992, have reduced these causes of the disease by more than 90 per cent.

Ray Borrow, the head of the vaccine evaluation department at the Health Protection Agency in Manchester, said: "I believe we should be very excited indeed. Ten years ago we had success with a vaccine against group C disease but, so far, we have had no real prospect of controlling group B disease.

"There are 20,000 to 80,000 cases of meningitis B globally and roughly 1,200 cases in the UK each year, of which 10 per cent result in death. The prospect of one vaccine that protects infants worldwide against [meningitis B] would be a key achievement in global disease prevention of our time."

Generations of parents have lived in terror of meningitis because it targets the young, strikes with unnerving speed and ferocity, and kills one in 10 of those it infects. Among those who survive, many suffer permanent disability including deafness, neurological problems and loss of fingers and limbs.

The meningitis bacterium lives harmlessly in the noses and throats of one in 10 people but, for reasons that are not fully understood, can erupt into a life-threatening illness that causes inflammation of the membrane around the brain – the "meninges" – and leads to death within hours. With vaccines already available against group C and Hib meningitis, group B is the dominant strain in England, accounting for 84 per cent of the 1,283 cases of meningococcal disease recorded last year.

Developing an effective group B vaccine has presented a much bigger challenge because there are scores of different strains circulating in Europe and most parts of the world. Group B vaccines have been developed and are in use in Cuba and New Zealand but these are only effective against the single strains circulating in those countries.

The new vaccine contains multiple "antigens" – bacterial proteins designed to counter different strains – developed from a study of 85 strains of group B disease. It has so far been tested against three "representative" strains in the current trial.

The 150 babies in the study were given the vaccine at ages two, four, six and 12 months. Laboratory tests on blood samples showed they had better than 85 per cent protection against the three strains. The vaccine, developed by the Swiss multinational pharmaceutical company Novartis, is being tested by an independent team led by Elizabeth Miller, the head of the immunisation department at the Centre for Infections – part of the Health Protection Agency (HPA).

Dr Borrow, who heads the regional HPA laboratory in Manchester and is a member of the team, presented the findings to the European Society of Paediatric Infectious Diseases in Austria yesterday. He said the laboratory results for the group B vaccine were as good as those for the group C vaccine a decade ago "and we have now virtually eliminated group C disease". He added: "I am confident this vaccine will provide broad protection against a range of strains of group B disease. We have full data on three strains and partial data on two more strains which are representative of other components of the vaccine."

A third and final trial, involving hundreds of British children, began earlier this year. Assuming these tests are successful, it would still be "some years" before a vaccine was introduced, Dr Borrow said.

Andrew Pollard, the head of the Oxford Vaccine Group at Oxford University, said the initial results required confirmation to show the extent of the protection provided. "There is still along way to go but a vaccine that gave broad protection against meningitis B would be hugely significant, because this strain causes the most cases and the most deaths from meningitis in Britain and around the world."

A spokesman for the Meningitis Research Foundation said: "This is really exciting news. It is what we have been working towards. If it goes through phase three trials [successfully], we will have cracked the holy grail. It will be virtually the end of the story on meningitis and it will put organisations like ours out of business."

The vaccine was developed using a method called "reverse vaccinology" in which the genetic make-up of a single strain was first decoded. This yielded 600 novel proteins from which the vaccine was constructed, using genetic engineering to pick those that showed the greatest ability to stimulate the immune system.