On Thursday the WHO raised its alert on swine flu (H1N1) to the Phase 6 pandemic level, calling further spread of the virus inevitable. The world is now at the start of the 2009 influenza pandemic, the first in 41 years. At present scientists believe that swine flu is no worse that seasonal flu with weak virulence and no comparison to the deadly 1918 Flu pandemic.
The U.S. government will invest $1 billion to kick-start the process of H1N1 vaccine development. The seasonal flu vaccine already in development won't protect against the pandemic virus, so two flu shots may be needed for protection. Stepped-up production of the leading antiviral Tamiflu by Gilead and Roche is already under way.
GlaxoSmithKline (GSK) will start production of a pandemic vaccine in July, which can take six months, and will donate 50 million doses to WHO for poor countries. Additionally, Novartis reported that it has produced its first batch of experimental vaccine. Baxter has also completed testing and evaluation of the H1N1 influenza virus and is now in full-scale production of a vaccine. The firm is working to deliver a pandemic vaccine for use as early as July.
Coinciding with the pandemic flu news, flu vaccine makers have rallied, with European drug makers like GSK, Novartis, AstraZeneca, and sanofi-aventis showing a positive 5% move over the past two days. U.S. drug stocks Abbott Laboratories (ABT), Merck & Co. (MRK), and Pfizer (PFE) also rebounded. A number of smaller developers also have the technology and manufacturing to assist the government, as does some larger drug companies like Crucell, NovaVax, and Vical.
Last month the FDA issued warning letters to three diagnostic manufacturers—Becton Dickinson, Luminex, and Prodesse—for allegedly marketing flu tests for H1N1 virus that had not yet been cleared by the agency. The companies have reportedly now complied with the agency’s instructions.
The diagnostic tests can detect Flu A+B but have not been evaluated for the identification and reporting of specific flu strains such as H1N1. The CDC has the only molecular diagnostic test for H1N1 cleared by the FDA for emergency use only. Of the pure-play diagnostic companies Quidel and Inverness have made the most significant stock rallies on the swine flu news beginning last April.
The swine flu virus is a mix of human, bird, and pig flu gene segments. It can change quickly and could mix with its seasonal cousin and perhaps with the H5N1 bird flu circulating widely in poultry. Vaccine makers are challenged by the constantly mutating HA surface protein of the virus and are looking for a conserved region of the protein that will make a vaccine with more life-long immunity. Mutations in the HA molecule also affect its ability to bind to receptors in the human respiratory tract that are critical for viral transmission. The CDC has sequenced 10 or more complete swine flu viral genomes and hope to have a prototype vaccine in a month.
“Globally we have good reason to believe that this pandemic, at least in its early days, will be of moderate severity,” remarked the director-general of WHO, Margaret Chan, M.D. Although the pandemic is moderate in terms of severity with the majority of patients experiencing only mild symptoms and a full recovery, the new strain is spreading easily from one person to the next as well as from one country to another in more than one region of the world.
The WHO reported 28,774 cases in 74 countries, including 144 deaths with a sharp jump in Australia where 1,263 cases on Thursday and rising numbers in Britain, Japan, and Chile. The U.S. has confirmed more than 13,000 cases with activity in all 50 states.
The new H1N1 virus has occurred in individuals between 30 and 50 years, but overall most cases involve those under 25. Pregnant women are at increased risk for complications. About 57% of the cases are among people aged 5 to 24 with 41 % hospitalized, according to Anne Schuchat, M.D., rear admiral of the CDC.