he World Health Organization on Friday announced an end to the public health emergency of international concern over Zika, though it cautioned that the virus remains a significant and enduring health challenge.
The decision comes nine months after the UN agency first declared an emergency over Zika and its associated complications, which include devastating brain defects in babies infected in the womb and a paralyzing condition called Guillain-Barré syndrome in some people after infection.
Officials stressed, however, that the virus remains a threat wherever it can be transmitted by mosquitoes or through sex with an infected individual and that health officials must not let down their guard.
“We are not downgrading the importance of Zika,” said Dr. Peter Salama, executive director of the WHO’s health emergencies program. “Zika is here to stay, and the WHO’s response is here to stay.”
Salama said the WHO’s assessment of the risk posed by Zika is not altered by the decision to call an end to the public health emergency.
Some observers fear the decision could make it harder to garner funding for Zika research that they believe remains a high priority. They also worry that efforts to detect and report spread around the world will ease.
“I think WHO’s decision is unwise,” said Lawrence Gostin, an international health law expert at Georgetown University. “The international response to Zika has always been lethargic, and we still don’t have effective mosquito control, vaccines, or treatment. WHO’s decision will give countries even less reason to invest in critically important preparedness and research.”
Still, an expert committee advising the WHO on Zika concluded that a “public health emergency of international concern,” as its known in the agency’s vernacular, was no longer needed. Instead, a strong and ongoing Zika response must become part of the WHO’s regular operations, said Dr. David Heymann, chair of the committee that advised the WHO on the issue.
Heymann, a longtime former WHO official who now teaches infectious diseases epidemiology at the London School of Hygiene and Tropical Medicine, admitted the committee was concerned that lifting the emergency would lower the priority given to Zika by governments and other funders.
“But by escalating this to a program that is of much greater importance within WHO, a robust program with a technical advisory group, it’s thought that this should not decrease the resources,” he said.
Maintaining vigilance against the virus is critical, said Dr. Thomas Frieden, director of the Centers for Disease Control and Prevention.
“I think it would be very unfortunate if this action by WHO resulted in governments, health workers, pregnant women, or their sexual partners thinking that Zika is any less serious than they thought it was yesterday. Because it’s not,” he told STAT.
“And, in fact, the more we learn about Zika, the more concerned we are.”
The CDC also stressed in a statement that the WHO’s decision does not obviate the need for pregnant women to avoid travel to places where Zika is spreading.
The WHO’s designation of a public health emergency was made on Feb. 1. In practical terms, it meant that its recommendations aimed at curbing the spread of Zika, minimizing economic impacts or promoting collaborative research carried more clout among member states.
Since then, 27 more countries have reported Zika-related birth defects. The actual number of affected births has fallen far short of expectations, though Salama warned that there is likely a significant underreporting of cases.
Early estimates of upward of 6,000 affected births in Brazil have been revised sharply downward, to about 2,100 at last count. Globally the total is about 2,300.
Of the 27 other countries that have reported cases of Zika-related birth defects, Colombia has recorded the second highest tally, 57. In most countries, the cases are in the single digits.