Expert worried over swine flu vaccine safety
A leading virologist has raised concern about the safety of the swine flu vaccine that Indian companies are trying to bring out in a hurry at the request of the government.india Updated: Aug 22, 2009 15:58 IST
A leading virologist has raised concern about the safety of the swine flu vaccine that Indian companies are trying to bring out in a hurry at the request of the government.
Health Minister Ghulam Nabi Azad had said on August 10 that the Serum Institute in Pune, Bharat Biotech in Hyderabad and Panacea Biotech in New Delhi are working to develop the vaccine from A (H1N1) virus strains supplied by the World Health Organisation.
Azad had said that the Indian Council for Medical Research has been asked to help the companies to ensure fast-track production of the vaccines. The Serum Institute has started animal trials and expects to bring out the vaccine as early as next month.
"The companies that have been entrusted with the manufacture of influenza vaccine have no experience to manufacture and evaluate a totally new vaccine and that too in such a short time," Kalyan Banerjee, former director of the National Institute of Virology (NIV) in Pune said in an e-mail interview.
The companies do have experience to manufacture well tested and established vaccines but not a totally new vaccine, he cautioned.
Banerjee surmised that the vaccine would be manufactured in "embryonated" hen's eggs.
"Such a vaccine has been used for strains circulating in different years and are of limited use. I wonder whether extensive safety and immunogenic data are available," Banerjee said.
"As desired by the government, the vaccine manufactured by these companies would be for a mass vaccination campaign. I would certainly not get myself vaccinated unless extensive safety and immunogenic data are available and risk benefit ratio is impartially analysed," he added.
Banerjee also questioned the purpose of the H1N1 vaccine.
"By the time the vaccine is well studied and found fit for mass use, the epidemiology of influenza would suggest emergence of a new strain. Suppose it is H2 or H3, N2 or N3 then the whole exercise would be a futile."
Questions about the vaccine's safety have also been raised in the British press. An Aug 15 report in the London Daily Mail said that the British Health Protection Agency (HPA) had on July 29 sent a letter to about 600 neurologists asking them to look for signs of Guillain Barre Syndrome (GBS) in persons receiving the vaccine. GBS attacks the lining of the nerves, causing paralysis and inability to breathe, and can be fatal.
The report said the letter from HPA "is the first sign that there is concern at the highest levels that the vaccine itself could cause serious complications".
According to the news report, the HPA letter refers to the use of a similar swine flu vaccine in the US in 1976 when 500 cases of GBS were detected. The vaccine was withdrawn after just ten weeks when the link with GBS became clear. More than 40 million Americans had received the vaccine by the time the programme was stopped after 10 weeks.
The US government paid out millions of dollars in compensation to those affected. A retrospective study found a possible eight-fold increase in the incidence of GBS following mass vaccinations in the US.
When asked for comments, HPA spokesman David Daley told IANS that GBS "has long been identified as a potential adverse event that would require enhanced surveillance following the introduction of a pandemic vaccine".
He, however, said "there is no evidence to suggest there is an increased risk of GBS from this vaccine."
Daley said that "the HPA is working in collaboration with the Association of British Neurologists Surveillance Unit (BNSU) and the British Paediatric Surveillance Unit (BPSU) to establish enhanced surveillance of GBS".
Rajeev Dhere, director of vaccine production at the Serum Institute of India, did not reply to questions about how his vaccine will address the GBS concerns.