Clinical science is catching up with the West African Ebola outbreak that has killed more than 11,000 people since last year in countries such as Guinea, Sierra Leone and Liberia.
An experimental Ebola vaccine — rVSV-EBOV — is proving highly effective against the deadly virus. And yet, almost everything that is going right with this historic, global-health initiative stands in direct contrast to the fear-mongering and anti-government sentiment we’ve seen recently from domestic anti-vaccinationists such as actor Jim Carrey.
As parental protests surged in April against a California bill that strictly limits childhood vaccination waivers, a coalition of governments, private industry and charitable organizations had already launched an Ebola vaccine trial in Guinea.
Now, the researchers — reporting with lightning-fast speed on vaccination data as recently as July 20 — have unveiled a stunning success: 100% protection against the Ebola virus, according to the criteria laid out in the trial design.
Meanwhile, back in California, the parents who oppose similarly effective vaccines are trying to recall the state senator (and pediatrician), Dr. Richard Pan, who introduced the childhood vaccination bill in the wake of his state’s easily preventable measles outbreak that began in December. Gov. Jerry Brown signed the bill into law June 30.
Many California parents just don’t buy the advice of doctors and government leaders. They share Carrey’s attitude that vaccines are the work of greedy corporations and politicians — an apparatus more interested in making money than safe products.
Unfortunately, such anti-vaccine sentiment isn’t limited to educated, well-off Americans who benefit from the hard-won herd immunity around them. We see the same phenomenon in developing countries as well. In 2003 and 2004, five Nigerian states boycotted the polio vaccination after the spread of unfounded rumors claiming the vaccine damaged fertility and was part of an international conspiracy to limit the Muslim population.
The worldwide polio eradication campaign suffered a serious blow when a large polio outbreak ensued from 2003 to 2006. Getting the campaign back on track cost hundreds of millions of dollars.
Such anti-vaccine beliefs are sticky, and even a decade later about a third of polio vaccine opponents in Nigeria claimed the vaccine was somehow harmful.
So it’s disturbing to see that even in Ebola-stricken Guinea, about a third of the 3,035 Ebola contacts eligible for immediate vaccination either refused the vaccine or were absent for it. Thirty-four people consented to vaccination, only to change their minds before getting the injection.
In the trial’s comparison arm, where people could receive the vaccine three weeks later than the immediate group, 450 of the 2,380 eligible people declined the vaccination or weren’t around to get it.
We’re talking about people who were either direct contacts of someone who had just been diagnosed with Ebola, or contacts of those contacts. It’s hard to imagine a more motivating situation.
Yet the power of rumor knows few bounds. An investigator for the STRIVE trial — which is testing the same rVSV-EBOV vaccine under a different study design in Sierra Leone — told PBS Newshour that rumors about the vaccine’s safety became a hurdle when launching the trial in that country as well.
The paper, just published in The Lancet, a medical journal, relates the fantastic initial results of the phase III trial. That’s the type of large study required for drug licensing.
While longer-term data is needed — it appears the vaccine can stop outbreaks, but how long its protection lasts and how many people need to be vaccinated to produce herd immunity is still undetermined — the vaccine already received an important vote of approval from the body overseeing the study. The delayed vaccination arm is ending, and it’s no longer considered ethical to withhold the vaccine from anyone who’s a candidate.
No contacts who received the vaccine immediately after the identification of an infected patient developed the Ebola virus disease by the study’s 10-day criteria. And indeed, none of the 3,512 vaccinated people — whether the vaccine was immediate or delayed — developed Ebola more than 6 days after vaccination. That’s a meaningful marker, because it probably takes that period of time for the vaccine to start fully working.
So now that rVSV-EBOV manufacturer Merck seems poised to gather the necessary licensing data, vaccine skeptics must be expecting an enormous payday for the company. It’s hard to imagine the vaccine becoming a cash cow for anyone, given its target population in West Africa. Indeed, a charitable foundation — Gavi, The Vaccine Alliance — will step in to fund much of the initial immunizations, should the vaccine make it to market.
In California, the government is doing what it must to protect the people, just as Guinea is doing what it must in supporting this trial. Leaders such as Dr. Pan deserve praise, not recall attempts, as do the numerous organizations backing the Ebola vaccine trials.