The Zika virus, it appears, is here to stay. At the end of November, the WHO reclassified the Zika virus from a “public health emergency of international concern” to an ongoing threat. That doesn’t mean Zika is no longer a problem. Just the opposite: it means the WHO expects Zika to remain a problem for the long haul.
Zika is now endemic in many new populations. Cases continue to appear. In New York City, for example, there have been five babies born with Zika-related brain malformations since this July. Four cases of Zika were confirmed this fall in Ireland; in the same time period, sixteen pregnant women in Singapore were diagnosed with Zika. Fifty-eight countries are currently reporting active Zika transmission.
Transmission of Zika goes beyond just mosquitoes. Zika, we now know, is sexually transmitted. Like Ebola, it can be transmitted even after a patient has returned to normal health. This means that eradicating mosquitoes and promoting the use of repellants isn’t enough interrupt the spread of the virus. Consistent condom use will be required as well. And, like Ebola, we do not yet know how long condoms remain necessary after the infection passes.
There is still no useful guidance for couples who want to get pregnant and live in Zika-endemic areas. The Centers for Disease Control and Prevention, for example, offers advice to travelers to Singapore: “If you are thinking about pregnancy, talk with your health care provider and wait to become pregnant…You also should use condoms after travel to protect your sex partners from Zika even if you are not pregnant or trying to become pregnant.” What happens to the people who live in Singapore and want to get pregnant? The Ministry of Health of Singapore website offers no advice; its section on Zika and pregnancy is aimed at women who are already pregnant.
We’re a long way away from a vaccine.
The US National Institutes of Health launched a clinical trial in August of a Zika vaccine, but it’s an early stage trial of an early stage product. This kind of early stage trial looks at two things – 1) is the vaccine safe, and 2) does it create an immune response in the human body. Even if it is safe and it does create a response, it will need a second trial to discover if the response it generates actually protects against Zika.
WHO removed Zika from the list of public health emergencies because the virus needs its own response and its own funding. It cannot simply be lumped in with emergencies and expected to pass with time.
Zika needs an active, global response, akin to programs like Polio Eradication or Measles and Rubella Initiative. We will see if the international system can produce one.