07 November 2003

SARS Vaccine Not Expected for Several Years, Experts Say

Any winter outbreak to be met with current "control measures"

A panel of international public health experts concludes that it is not possible to develop a vaccine against severe acute respiratory syndrome (SARS) in less than two to five years. That means if a global outbreak of the flu-like respiratory disease should recur in 2004 as it did in 2003, public health workers will have to rely on the same tools with which they fought the sometimes-fatal illness this year.

"We must be ready to manage a possible resurgence of SARS through the control measures that work -- surveillance, early diagnosis, hospital infection control, contact tracing and international reporting," said Dr. Lee Jong-wook, director-general of the World Health Organization (WHO). His remarks came in a November 5 press release issued after a two-day WHO meeting on SARS held in Geneva.

The meeting convened an international panel of researchers to discuss what they have learned about the disease since it sprang on the world in early 2003 and what they have yet to learn. Identifying the best strategy for formulating a vaccine was also an important topic before the group, according to the release.

The normal development and trial period for a new vaccine runs up to five years. Attempting to accelerate that schedule would require "an unprecedented level of international cooperation," according to WHO vaccine specialist Dr. Marie-Paule Kieny.

Public health experts suspect it is likely that SARS will behave like other coronaviruses to which it is related. These cold and flu-causing microbes tend to become dormant in warmer months and re-emerge in colder months. With those colder months arriving in the Northern Hemisphere, health officials are taking steps to respond more rapidly than during the first outbreak. In September, U.S. Secretary of Health Tommy G. Thompson explained the SARS preparedness effort. The Department of Health and Human Services "is continuing to work with the free market medical community as well as the scientific community to make sure that our nation will be fully prepared if SARS re-emerges," he said.

Following is the text of the WHO press release:

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WORLD HEALTH ORGANIZATION
November 5, 2003

Global search for SARS vaccine gains momentum
Remarkable progress but no vaccine this year say researchers

GENEVA -- More than 50 leading SARS researchers from 15 countries have concluded that a safe and effective vaccine would be an important complement to existing SARS control strategies. Most of the experts agreed, however, that a SARS vaccine will not be available in time should an epidemic reoccur at the end of this year.

The World Health Organization (WHO) Consultation on SARS Vaccine Research and Development reviewed progress in the field and identified ways to accelerate the development and evaluation of SARS vaccines.

"Efforts to develop a safe and effective human vaccine against SARS and the level of international collaboration are very encouraging. But in the immediate term, we must be ready to manage a possible resurgence of SARS through the control measures that work -- surveillance, early diagnosis, hospital infection control, contact tracing and international reporting. Research must continue to determine if, how, and how soon a vaccine will add to these existing control measures," said Dr LEE Jong-wook, Director-General of the World Health Organization.

The two-day meeting, which finalized recommendations this week, reviewed epidemiological information relevant for SARS vaccine development and evaluation, and what is known on how the SARS coronavirus causes disease in humans. The group also discussed the genetic variability of the SARS coronavirus, to identify the best strains to be included in future vaccines. The discussion on SARS vaccine development was guided by extensive information available on vaccines against animal diseases caused by related coronaviruses. Finally, the group reviewed recent work on experimental vaccines in animals, and how that information can be used to initiate future clinical trials in human volunteers.

The first clinical trial on an inactivated SARS vaccine could begin as early as January 2004. However, it is difficult to say when a vaccine might be available. A resurgence of SARS may accelerate the process and result in a vaccine within two years. If there is no big outbreak of SARS then the vaccine will follow the classical development path, and would not be ready for four to five years. "If we are to develop a SARS vaccine more quickly than usual, we have to continue to work together on many fronts at once, on scientific research, intellectual property and patents issues and accessibility. It is a very complicated process involving an unprecedented level of international cooperation which is changing the way we work. However urgent the need for a vaccine, safety and quality must never be compromised. But, it is clear the sooner we can develop a vaccine against SARS the better prepared we will be in case the disease reappears," says Dr Marie-Paule Kieny, Director, WHO Initiative for Vaccine Research.

In addition to the scientific discussions, the group considered how patents and intellectual property issues and their safeguards can help rather than hinder the rapid development of SARS vaccines, and ensure that once developed they are available in both industrialized and developing countries.

Specific regulatory considerations for the clinical evaluation and licensing of SARS vaccines were also brought into focus. In particular, that SARS vaccines might have to be licensed in the absence of efficacy data generated in humans. Indeed, clinical efficacy trials usually conducted to produce such data might prove inappropriate in the case of SARS, given the severity of disease outcome, its relatively rare occurrence so far and the urgency of developing the needed vaccines.

Representatives of public institutions and pharmaceutical companies presented progress in the development and evaluation of candidate SARS vaccines, and meeting participants examined the specific considerations on the development and evaluation of whole-inactivated SARS vaccines.

Further consultations will be held by WHO to review progress and to maintain the present high level of international collaboration.

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