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Thursday 17 Aug 2017 | 07:46 | SYDNEY
Thursday 17 Aug 2017 | 07:46 | SYDNEY

Zika: We haven't done enough

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COMMENTS

24 October 2016 17:33

In February, the WHO declared the Zika virus a Public Health Emergency of International Concern (PHEIC). Determined to avoid another Ebola-like failure, it called for a coordinated international response to improve Zika surveillance, detection and diagnostics, vector control and expedited development of vaccines. How effective has the response been?

The virus continues to spread rapidly, from 23 countries (mainly in Latin America) in February to 67 countries as of 13 October, including 47 countries in the Americas, seven in the Western Pacific and three in Southeast Asia. Moreover, 22 countries have reported microcephaly and other Zika-associated symptoms and 19 countries have reported an increased incidence of Zika infection among Guillain-Barré syndrome (GBS) cases. The WHO has not released updated global estimates of Zika cases, though earlier this month the US Centres for Disease Control and Prevention (CDC) reported 3936 cases in US states (878 in pregnant women), and 25,871 cases in US territories (1806 in pregnant women).

What do these figures and the cross-regional spread of Zika indicate about the effectiveness of the response so far? Have governments and international organisations failed the populations they seek to protect? Not necessarily.

The first point to make is that it is difficult to assess the effectiveness of public health interventions. This is because (a) it is hard to determine what would have happened if the public health response was different and (b) there are a multitude of extrinsic, often volatile factors beyond decision-makers’ control (such as environmental factors, relative population density, and the way a disease or virus behaves and adapts).

A more valuable approach, therefore, is to examine factors over which decision-makers do have control (such as the haste, extent and combination of interventions) with a view to finding where the response has been effective; where, why, and how it failed; and, perhaps most importantly, who is accountable. This process allows us to see where opportunities were leveraged or lost and to highlight the true successes and failures in the response so far.

To start with, good public health policy responses are evidence-based. So, what to do when, as in the case of Zika, we do not have a strong knowledge base on which to form our response? We start from scratch. 

This required the ‘coordinated international response’ requested by the WHO. Overall, this call was answered. Supranational organisations, governments, NGOs, industry, scientists, and healthcare workers collaborated. Supranational organisations provided guidance that was adapted as needed and implemented at national and local levels, mainly in the form of prevention efforts (such as mosquito spraying and removal of stagnant water) and communicating key public health messages based on best available knowledge. But this initial response did not secure funding for more consequential action. Herein lay the first battle.

Ultimately, funding depends on political/donor will, and such will requires impetus. In April, the CDC provided such impetus by confirming Zika is a cause of microcephaly and other severe foetal brain defects. Establishing this causal relationship was vital. The scientific community's consensus was an early success and a major win in the battle against Zika, as it allowed decision-makers to allocate funds, drive prevention efforts, focus research activities, and justify and inform public health messages about the risks of Zika.

At the supranational level, the Zika-microcephaly link allowed the WHO and partners to justify and define a strategic response to Zika and allocate funding to prevent and manage its associated medical complications. WHO estimates that US$122.1 million is necessary to effectively implement the Zika Strategic Response Plan from July 2016 to December 2017. However, as of earlier this month, donor contributions totalled approximately US$24 million, less than 20% of the requested amount. 

Resource mobilisation efforts have also struggled to reach targets at national levels. In February, the White House requested US$1.9 billion in emergency funding from Congress to respond to Zika, but the request repeatedly stalled due to disputes over how it would be paid for, family planning controversies (read: Zika-related abortions) and other issues. As a result, it took nearly eight months for US$1.1billion (US$800 million less than requested) to be attached to a bill that temporarily extends funding into the 2017 fiscal year, a short-term solution.

Therefore, one could argue that resource mobilisation efforts at both supranational and national levels have failed to yield the financial commitment required to effectively manage Zika. However, the real test is not whether key actors can mobilise a seemingly arbitrarily defined amount, but rather whether they can mobilise enough resources and maximise efficiencies to create a response that works. If so, the resource gap does not necessarily equate to failure.

When considering the efficacy of the Zika response within the framework of the WHO’s call to action, we must also consider progress in terms of detection, prevention, support and research efforts, all of which are dependent on the aforementioned funding.

The WHO’s Strategic Response Plan addresses all four of these factors to support national governments and communities in their Zika response.

Most countries have implemented efforts to improve detection. In light of the virus’s emergence in Southeast Asia, all countries in the region have accelerated prevention procedures and have the laboratory capacity to conduct Zika virus testing and identify microcephaly. Thailand recently confirmed two cases of Zika-related microcephaly, illustrating that procedures are being followed.

Zika and microcephaly prevention efforts span from vector control to contraception. Promisingly, at-risk states have designed and implemented Zika Preparedness and Response Plans, aligned with WHO’s. However, consistent with history, the poorest are the most vulnerable and lack ability to pay for repellents, bed nets and contraception, often available only via the private market and less accessible in rural areas. Furthermore, Latin America has the highest proportion (56%) of unintended pregnancies worldwide.

On 9 March, the WHO prioritised research and development efforts, which now focus on diagnostics, vaccines, and innovative vector control tools. Meanwhile, as of 2 March, 67 companies and research institutions were already working on a number of products (31 on diagnostics, 18 on vaccines, eight on therapeutics, ten on vector control). In fact, by August the first early-stage study had commenced to evaluate a vaccine’s safety and efficacy.

Eventually this surge of research will be of value, but in the meantime, significant knowledge gaps remain. Consider now that more than half the world’s population lives in areas infested with Aedes aegypti, the mosquito responsible for spreading Zika, and that researchers recently detected Zika in monkeys and in female Aedes albopictus mosquitoes, a species that can survive temperate winters. It is clear that Zika has immense potential and could expand far beyond the initial geographic estimates, and that we need to fill knowledge gaps quickly.

Overall, the initial response to Zika was both prompt and coordinated. Though it has failed (as yet) to mobilise the finances sought, the WHO is demonstrating its ability to lead a collaborative global health response. Likewise, even resource-constrained countries appear to be leveraging cost-effective control, prevention and detection campaigns, though require additional support to reach the most vulnerable populations. The scientific community and pharmaceutical industry (the latter albeit enticed by market forces) responded hastily and in line with the WHO’s call. The most significant failure so far is the delayed US response and lack of stewardship within the region, though this is symptomatic of the reliance on political lobbying in US decision-making processes.

Moving forward, the efficacy of prevention, detection and supportive efforts will depend on the extent to which donors and local agencies continue to monitor and report cases, spur and leverage political will and support resource-constrained communities.

Photo courtesy of Flickr user Agência Brasília

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