A One Health issue...
Yellow fever still spreading in Luanda, Angola
By *Jack Woodall, PhD – Provided to One Health Initiative website May 27, 2016
As of 25 May 2016, Angola has reported 2536 suspected cases of yellow fever with 301 deaths. Among those cases, 747 have been laboratory confirmed. This is 33% more cases in the week since the previous World Health Organization (WHO) update of 20 May, a significant increase. Despite vaccination campaigns in Luanda, Huambo and Benguela provinces, circulation of the virus persists in some districts. Vaccination campaigns started on 16 May in Cuanza Sul, Huila and Uige provinces (after the disease spread there weeks ago). Lunda Norte has reported, for the first time since the beginning of the outbreak, 5 autochthonous laboratory confirmed cases in 2 districts.1
Nobody is going to see why yellow fever is a global threat when that relatively small number of cases and deaths is perpetuated by the media. Ignored since March is a report from WHO expert Sergio Yactayo after a visit to Angola that the official statistics were an undercount by a factor of 10, so that at that early stage there were already thousands of cases and hundreds of deaths.2
Nevertheless, it is of considerable concern that after nearly 3 months of trying, Angola has not yet succeeded in vaccinating the whole of the capital district of Luanda, and used up 17 million doses of scarce vaccine.
On 16 April 2016 a group of yellow fever experts headed by international vaccine expert **Thomas Monath [MD] published an article in Lancet online calling for use of a one-fifth dose of the vaccine to expand a five-dose vial to protect 25 people instead of only five.3 They reference two independent papers published in 2013, backed up by a modeling paper published this month (May) online, which have shown that a one-fifth dose is still protective for adults. Angola received 11.7 million doses of yellow fever vaccine on 18 May to supplement its ongoing campaigns. But this could be expanded to more than 58 million if the one-fifth dose were to be authorized now.
WHO has some legitimate concerns about the protective effect of the lower dose for children, and the Wellcome Trust is willing to fund a field test to confirm this, but waiting for its execution and evaluation will take months, during which full-strength vaccine will be irrevocably used up, perhaps unnecessarily. It should be borne in mind that half the population of Angola is under 15 years old (UNICEF’s definition of a child) and many will have already been immunized against yellow fever during the last 10 years through the Angola national EPI program, so that a lower dose would at the least boost their immunity. For those who missed their EPI dose it would very probably give them sufficient immunity to protect them from fatal infection.
WHO has the authority to declare an EUAL (Emergency Use Assessment and Listing) allowing use of that lower dose, even without declaring a PHEIC (public health emergency of international concern) -- which, on the advice of an expert committee meeting on 19 May, it has decided not to do. Instead, WHO has commissioned a White Paper on vaccine sparing, postponing a decision until June or later, which means more full-strength vaccine irrevocably used up every day.
WHO expects manufacturers to produce a few million more doses by August, but unless they start conserving vaccine now by lowering the dose, it will be too late to take full advantage of it.
Doesn’t anybody see that there is a vaccine emergency, even if there isn’t a public health emergency?
1. WHO Situation Report Yellow Fever 26 May 2016 http://apps.who.int/iris/bitstream/10665/207328/1/yellowfeversitrep_26May2016_eng.pdf?ua=1 Accessed 27 May 2016
2. Voice of America Vaccinations Needed to Stop Yellow Fever Outbreak in Angola 18 Mar 2016 Accessed 27 May 2016 http://www.voanews.com/content/measures-needed-to-stop-spread-of-yellow-fever-from-angola/3243747.html Accessed 27 May 2016
3. Monath, TP, Woodall JP, et al. Lancet. Yellow fever vaccine supply: a possible solution. 2016 Apr 16; 387(10028):1599-600. doi: 10.1016/S0140-6736(16)30195-7. Epub 2016 Apr 14. Accessed 27 May 2016
*Dr. Woodall is a co-founder of ProMED-mail and a former member of the One Health Initiative team
**Dr. Monath is a co-founder member of the One Health Initiative team