Researchers at the University of Antwerp are currently comparing 4 potential vaccines for H1N1v, also known as swine flu or Mexican flu. 300 to 400 volunteers will be recruited for the tests. “There is a good chance that a Mexican flu vaccine is available early November”, expects vaccine expert prof. dr. Pierre van Damme, director of the Centre for the Evaluation of Vaccination (CEV), a department of the Vaccine & Infectious Disease Institute (VAXINFECTIO) at the University of Antwerp.

“We were contacted by a number of vaccine producers to test their vaccines as soon as they had a test version”, explains Van Damme. “The CEV can look back on more than 20 years of experience in the scientific evaluation of test vaccines for different producers. We have been cooperating with some of these vaccine companies for many years. Obviously, they do not want to lose time now. That is why the number of test centres has been limited.” Together with the University of Antwerp, the University of Ghent and some centres in Finland, France and Germany are involved in the testing.

“Most producers will have their test vaccines ready by the middle or end of August” says Van Damme. “But a vaccine can only be launched on the market when is has been tested on healthy volunteers. This procedure is also followed for other test vaccines. The vaccination of volunteers will take place in the course of August and September, because all test vaccines come with a vaccination scheme of 2 doses.”

Vaccine probably available from beginning of November
Van Damme expects the final test results in October. "Then the test reports will be delivered to the proper authorities (e.g. EMEA) and it is up to them to give the go-ahead to the vaccine. Consequently, the mass production can start and a few weeks later the vaccine can be launched. This means that a vaccine will probably be available by the beginning of November.”

Van Damme points out that the production will not immediately be sufficient to vaccinate everyone. “That’s way most countries are now identifying target groups to be vaccinated first. It concerns people with crucial professions during a pandemic (e.g. health workers), standard high-risk groups (e.g. people aged over 65 with underlying disorders or people who are chronically ill) and potentially also young children because they can play an important role in the spreading of the flu.”

Time pressure
Van Damme confirms that there is time pressure, but emphasises the need to follow the standard evaluation procedure. “Luckily, this procedure is very similar to the one we use with the winter flu, for which we also use a killed or inactivated vaccine. So we know what side effects we can expect, and we can be certain that the test vaccine will not cause flu symptoms.”

Whether the vaccine will be available on time, is an open question. “On the basis of recent epidemiological data, we estimate the chance that the Mexican flu will quietly fade away (as SARS did a few years ago) to be nearly zero. The data from Spain and the United Kingdom clearly show an increasing spread of the Mexican flu. It is still not clear what the course of the disease will be, but currently the disease symptoms and complications seem to be in the order of the annual winter flu. This situation can continue, but there is also a chance that the flu becomes more serious, for instance when the virus mutates or exchanges genetic material with other winter flu viruses that start circulating. We need to be prepared for these scenarios as well.”

(Science Daily, 16/07/2009)