Debate on vaccine safety rages as Nigeria nears polio-free status

FRESH concerns over vaccine safety have been blamed for the recent measles epidemic in the United States even as Nigeria enters the seventh month without any new case of the Wild Polio Virus (WPV).

     Experts are worried that the rise in measles cases in the United States due to refusal of the vaccine by most of the citizens may trigger global epidemic of the disease and the return of other diseases that have been eradicated with vaccines such as small pox.

     It is also feared that the rejection of vaccination may spread to developing nations such as Nigeria where refusal of the polio vaccine in the 1990s led to unprecedented spread of the virus.

    Latest figures from the United States Food and Drug Administration (FDA) show that, in 2000, measles was declared eliminated in the US. But last year saw a record number of measles cases, 644, over 27 US states. This year is unlikely to be any better, with 102 cases reported so far. 

     According to the CDC, the Measles Mump and Rubella (MMR) vaccine is 93 to 97 per cent effective at preventing measles.

   Measles is a highly contagious respiratory disease caused by infection with the morbillivirus. Onset of the disease usually begins with a fever, cough, inflamed eyes, runny nose and sore throat, before a red, blotchy rash appears all over the body.

     Common complications of the virus include ear infections and diarrhea, while more severe complications include pneumonia – the most common cause of measles-related death in children, and swelling of the brain, known as encephalitis, which can cause convulsions, deafness and brain damage.

     Meanwhile, according to the Weekly Polio Update published last week by the Global Polio Eradication Initiative (GPEI), no new wild poliovirus type 1 (WPV1) cases were reported in the past week. Nigeria’s total WPV1 case count for 2014 remains six, compared to 53 in 2013. The most recent case had onset of paralysis on July 24, 2014 in Sumaila Local Government Area (LGA), southern Kano state.

    However, one new type 2 circulating vaccine-derived poliovirus (cVDPV2) case was reported this week in Gujba district of Yobe province (previously uninfected in 2014) with onset of paralysis on November 3, 2014. The most recent case had onset of paralysis on November 16, 2014 in Barde district of Yobe state. The total number of cVDPV2 cases for 2014 in Nigeria is now 30.

    To sustain the progress made, the Executive Director of the National Primary Health Care Development Agency (NPHCDA), Dr. Ado Gana Mohammed, said there is going to be National Immunization Days (NIDs) on March 21 to 25, 2015 using trivalent Oral Polio Vaccine (tOPV).  

     Mohammed told The Guardian: “Over seven months have passed since the most recent case of WPV1 had onset of paralysis in Nigeria. However, at least 12 months must pass without detection of WPV, in the presence of certification quality surveillance, before Nigeria would be considered as having stopped transmission of WPV.”

    The NPHCDA boss, however, said polio-free certification of Nigeria (and the entire World Health Organisation African region (WHOAFRO) would follow only after three years with high quality surveillance have passed without identifying WPV. He said intensified efforts are ongoing in the country not just to eradicate WPV, but also to urgently stop the circulating vaccine-derived poliovirus type 2 outbreak, which continues to affect the country. 

      Writing in an article for Forbes, Steven Salzberg, a professor of biomedical engineering, computer science and biostatistics at Johns Hopkins University School of Medicine in Baltimore, says this latest measles epidemic has been “fueled by growing enclaves of unvaccinated people.”

    “Anti-vaxxers have been relentless in the efforts to spread misinformation,” he adds. “Despite overwhelming scientific evidence that vaccines are beneficial, they endlessly repeat a variety false claims, such as vaccines cause autism.”

    “Over the past 15 years, dozens of studies involving hundreds of thousands of people have shown convincingly that neither vaccines nor any of the ingredients in them are linked to autism,” he continues. “Vaccines are not only safe, but they are perhaps the greatest public health success in the history of civilization.”

         In a press briefing at the end of last month, Dr. Anne Schuchat, director of the National Center for Immunization and Respiratory Disease at the CDC, said this year’s outbreak is a concern: “It’s only January and we have already had a very large number of measles cases – as many cases as we have all year in typical years. This worries me and I want to do everything possible to prevent measles from getting a foothold in the United States and becoming endemic again.”

     And according to the CDC, vaccination is the key to getting a “foothold” on measles in the US, and it is primarily lack of vaccination that has contributed to the recent outbreaks.

Safety of MMR vaccine is still questioned

      A report from the CDC found that last year, 79 per cent of measles cases occurred among people who opted out of the MMR vaccine due to personal beliefs.

     The CDC say the MMR vaccine is safe, and one dose of the vaccine is around 93 per cent effective at preventing measles, while two doses is approximately 97 per cent effective. 

      So why are many people still not getting themselves or their children vaccinated?

      Primarily, it is down to religious or personal beliefs. A report from the CDC found that last year, 79 per cent of measles cases occurred among people who opted out of the MMR vaccine due to personal beliefs. And these personal beliefs tend to be associated with worries that the vaccine is unsafe for children.

     This belief stems from a study published in The Lancet in 1998, conducted by British researcher Andrew Wakefield and colleagues from the United Kingdom (UK). In this study involving 12 children, Wakefield and his team suggested a link between the MMR vaccine and autism.

      Though other studies were unable to reproduce the findings, Wakefield’s research had a significant impact on vaccination coverage. In the UK, MMR vaccination rates fell from 90 per cent to 80 per cent, while measles cases began to rise.

      The study has since been retracted by The Lancet, having been deemed as “fraudulent” after undisclosed financial conflicts of interest were revealed by a journalist called Brian Deer in 2011. As a result, Wakefield lost his medical license. But regardless of this outcome, he stands by his findings, and so do many others.

      One of the most well-known supporters of Wakefield’s claim is former Playboy centerfold Jenny McCarthy, whose son developed autism, which she attributes to vaccination. She claims that current vaccines are unsafe and contribute to autism and other disorders.

      “I do believe sadly it’s going to take some diseases coming back to realize that we need to change and develop vaccines that are safe,” she said in an interview with the Chicago Sun Times last year. “If the vaccine companies are not listening to us, it’s their […] fault that the diseases are coming back. If you give us a safe vaccine, we’ll use it.”

     Many parents in the US support McCarthy’s statement, but the CDC and other health organizations warn that this perception toward vaccination is putting the public’s health at risk.

     Salzburg and Schuchat note that people should not underestimate how serious measles can be. Around one in 10 children with measles develop ear infections, which can lead to hearing loss, and around one in 20 develop pneumonia. In this outbreak alone, a quarter of infected individuals have been hospitalized as a result.

     “The news this year is concerning and serves as a warning that measles is still coming into the United States and that unvaccinated people can get exposed,” said Schuchat in a press briefing.

     “These outbreaks the past couple of years have been much harder to control when the virus reaches communities where numbers of people have not been vaccinated and, of course, when the virus comes into the country and exposing people at large venues where many people gather, the chances of exposure are greater,” she added.

       As such, the CDC and health care professionals across the country are calling for all individuals to ensure they receive the measles vaccination. Schuchat said:

     “I want to make sure that parents who think that measles is gone and haven’t made sure that they or their children are vaccinated are aware that measles is still around and it can be serious. And that MMR vaccine is safe and effective and highly recommended.”

     Meanwhile, Ministers of health, health leaders and other global public health experts who attended penultimate week’s Executive Board (EB) meeting in Geneva, Switzerland, were encouraged by progress towards achieving a polio-free world. Yet they warned that as long as the disease remained anywhere, children everywhere are at risk. The meeting noted that achieving eradication, a global public good, could only be achieved through global solidarity. 

     Reviewing latest global epidemiology and impact of emergency outbreak plans, the Board noted in particular the strong progress across Africa, which has not seen a case due to wild poliovirus in almost six months, and in stopping a devastating outbreak affecting the Middle East despite conflict and large-scale population movements affecting the region.

      The Board commended the unwavering commitment of governments, health workers, humanitarian organizations, Non Governmental Organisations (NGOs) and civil society across the region, underscoring what successes could be achieved in the spirit of global solidarity. The Board cautioned, however, that these positive developments needed to be further validated through intensified surveillance activities, including through rapid scale-up of environmental surveillance as appropriate. 

     At the same time, however, the Board expressed alarm at intensified transmission of the virus in Pakistan, which now accounts for 85 per cent of all new polio cases worldwide, and virus continuing to spread beyond its borders. Failure to eradicate polio in the last remaining endemic hotspots would result in massive resurgence of the disease, with virus spreading to cause outbreaks in polio-free countries around the world. 

       The Board noted the major ramp-up in Pakistan’s government commitment at all levels, to urgently address the situation through the development of an emergency ‘low season plan’ for the first half of 2015, which had all elements to rapidly eradicate polio. Success, however, hinges on its full implementation at all levels, and the discussions highlighted the need for strong international support to ensure eradication strategies in all remaining infected countries can be fully implemented. 

 The Board also noted the strong progress being made, in close coordination with Gavi, the Vaccine Alliance, towards preparing for the phased withdrawal of oral polio vaccines (OPV), and urged all countries to ensure global readiness for the coordinated global switch from trivalent OPV to bivalent OPV in early 2016, including by ensuring sufficient global supply of inactivated polio vaccine (IPV) to facilitate the switch, and equitable access to the global stockpile of monovalent OPV type 2 (mOPV2). The Board underscored the need to intensify efforts to urgently stop the persistent circulating vaccine-derived poliovirus type 2 (cVDPV2) outbreaks in Nigeria and Pakistan, which will be the trigger for the switch in April 2016. 

     On financing, however, Member States expressed grave concern at the ongoing funding gap affecting the programme, and the risk it posed to fully implementing the Polio Endgame Plan. It called on all donors to rapidly fulfill pledges and fill the residual funding gap as urgently as possible. This is critical not only for polio eradication, but also as the polio eradication effort represents a concrete contribution towards broader maternal and child health development goals. 

     Repeatedly, Member States paid tribute to the heroic work of frontline health workers, working under often difficult and dangerous conditions, risking their lives to reach children everywhere. 

      On legacy planning, Member States commended the GPEI’s infrastructure support to the Ebola outbreak, notably in Nigeria, calling it an example of ‘legacy in action’. It looked forward to continuing consultations to secure the legacy of the GPEI, including in particular on further supporting the strengthening of routine immunization. 

      Rotary International provided an impassioned plea for all stakeholders to redouble their efforts, while reiterating the unwavering commitment of Rotarians worldwide. Regional Director for the Eastern Mediterranean Dr Ala Alwan assured Member States of his region’s unwavering commitment to polio eradication, including in particular to supporting Pakistan through the immediate deployment of an additional 800 emergency surge staff. Director-General Dr Margaret Chan re-affirmed WHO’s commitment across all levels, and thanked all partners and stakeholders for bringing the world to the threshold of being polio-free. Turning to Pakistan, she concluded: “Your country will be the one that delivers a polio-free world. It will be a historic achievement.” 

        In short, there is clear and unprecedented support for completing eradication as urgently as possible, given the epidemiological opportunity, which presents itself. Success, however, requires a re-doubling of efforts by all stakeholders at all levels.