Novartis’s vaccine against H1N1 swine flu gave a strong immune response even after one dose in a pilot trial with 100 volunteers run by Britain’s Leicester University.
It showed a potentially protective immune response in 80 percent of subjects after one dose and more than 90 percent after two doses.
Experts have predicted that two shots will be needed to provide swine flu immunity but last month China’s Sinovac Biotech, the first company worldwide to complete clinical trials for an H1N1 vaccine, said a single dose of its vaccine proved sufficient.
Dr Iain Stephenson, the trial leader said: ‘The results suggest that one vaccine dose may be sufficient to protect against A(H1N1) swine flu, rather than two.
“The aim of the trial was to find out how many doses and what type of vaccine is needed to give protection. These initial results should help to plan vaccination campaigns in the autumn, including doses and timings.”
The trial evaluated the tolerability and immunogenicity of the vaccine. Different schedules and timing between vaccinations were tested. The vaccine schedule comprised one or two doses of 7.5µg MF-59® adjuvanted surface-antigen A/California/2009 vaccine derived from cell-culture. Results showed that the serum antibody responses
were highest among subjects who received two doses of vaccine, however a single vaccine dose also induced responses associated with protection against influenza. Hemagglutination-inhibition titres reached 1:40 or greater in 80 percent and more than 90 percent of those receiving one dose and two doses respectively. These would
satisfy the immunogenicity criteria as set out by European and US regulators. The findings showed that it is possible to induce protective antibodies against A(H1N1) infection within two weeks of administration of a single low-dose adjuvanted vaccine. Non-adjuvanted formulations were not evaluated in the study.
Additional pivotal clinical trials, with larger numbers of subjects and sponsored by Novartis, are already under way around the world. They will include more than 6000 adults and children.
‘The pilot trial results are encouraging,’ said Dr. Andrin Oswald, CEO of Novartis Vaccines and Diagnostics. ‘The study suggests that while two doses seem to provide better protection, one dose of our adjuvanted Celtura vaccine may be sufficient to protect adults against the swine flu. This is important information for public health authorities who prepare for vaccination in the coming months with limited vaccine supply.’
The pilot trial was led by Dr. Stephenson of the Department of Infection, Immunity and Inflammation at the University of Leicester. He is a clinical senior lecturer at the University, and a consultant in infectious diseases at the University Hospitals of Leicester NHS Trust. Dr. Stephenson said ‘the aim of the trial was to find out how
many doses and what type of vaccine is needed to give protection. These initial results should help to plan vaccination campaigns in the autumn, including doses and timings. We concluded that the MF59-adjuvanted A(H1N1) vaccine of low antigen content was well tolerated and generated antibody responses associated with protection against influenza, even after a single dose.’
Novartis is among a host of drug manufacturers racing to produce a vaccine for H1N1, drug makers GlaxoSmithKline (GSK) and AstraZeneca PLC (AZN) are among the companies also trying to produce a vaccine for so-called swine flu.
Novartis is benefiting from the fact that it can produce batches of the H1N1 vaccine through a cell-based method, as opposed to a production system based on eggs. The cell-based method shortens the turnaround time to production to roughly three or four months, from six months for egg-based methods.
