Scientists closer to poliovirus-free vaccine production

• Summit tackles meningococcal, pneumococcal disease
• Pfizer’s Prevenar 13 provides protection against pneumonia
* Product helps sickle cells patients, persons with HIV/AIDS

In a promising development for keeping the world polio-free after eradication, a recent study has produced stable polio vaccine using virus-like particles (VLP) in the place of live poliovirus.

The study published by the Global Polio Eradication Initiative (GPEI) used VLPs made of empty viral capsids – the viruses’ protein coats – to produce the vaccine which, in initial testing, worked as well as traditional inactivated polio vaccine (IPV) made from inactivated wild vaccine-virus strains in protecting against polio.

Also, the first West African Vaccine Summit has advanced on most effective ways of managing pneumococcal and meningococcal diseases even as it made recommendations for vaccination, the ethics of vaccination, and the vaccination of special population groups and mass gatherings.

Meningococcal disease describes infections caused by the bacterium Neisseria meningitidis (also termed meningococcus). It carries a high mortality rate if untreated but is a vaccine-preventable disease. While best known as a cause of meningitis, widespread blood infection can result in sepsis, which is a more damaging and dangerous condition. Meningitis and meningococcemia are major causes of illness, death, and disability in both developed and developing countries.

Pneumococcal disease is an infection caused by the Streptococcus pneumoniae (S. pneumoniae) bacterium, also known as pneumococcus. Infection can result in pneumonia, infection of the blood (bacteremia/sepsis), middle-ear infection (otitis media), or bacterial meningitis.

The World Health Organisation (WHO) says that pneumococcal disease is the world’s number one vaccine-preventable cause of death among infants and children younger than five years of age.

Medical Lead- Anglophone West Africa and East Africa Pfizer Vaccines, Deshnee Achary, in her welcome address said meningococcal disease is a major cause of morbidity and mortality worldwide with reported epidemics and outbreaks in different parts of the world. Achary said despite the availability of antimicrobial therapy, challenges remain in early recognition and prevention of disease, and several vaccines have been developed to date aiming at preventing disease spread.

She said MenACWY-TT (Nimenrix) has been extensively studied for use in different age groups and that Phase I and III randomized trials have demonstrated its immunogenicity when administered in children aged one year and older, adolescents and adults.

Professor of Medicine at the Obafemi Awolowo University (OAU) Ile-Ife, Osun State, Gregory E. Erhabor, said the worldwide health burden attributable to pneumococcal disease remains significant, particularly in children aged under five and adults aged over 65. Erhabor said Africa bears a large portion of this burden with the region having the highest global incidence and mortality rate of pneumococcal disease in children younger than five years.

He said addressing child pneumococcal disease would bring us closer to realizing the fourth United Nations Millennium Development Goal, which pledges to reduce the mortality of children under five years by two-thirds.

Erhabor said the importance of disease prevention is paramount and clinical evidence has demonstrated that immunization with pneumococcal conjugate vaccines (PCVs) results in a reduction in the incidence of pneumococcal disease.

The professor of medicine said the vaccine has been shown to be very helpful for sickle cell patients and persons with Human Immuno-deficiency Virus (HIV)/Acquired Immune Deficiency Syndrome (AIDS). Erhabor said there a plan for development of guideline for the use of Prevenar 13 for people living with sickle cell disease and HIV/AIDS.

Director of Corporate Affairs, Pfizer Nigeria and East Africa Region, NEAR, Mrs. Margaret Olele, said PCV Prevenar13, which was launched at the Summit has demonstrated real-world effectiveness against: invasive pneumococcal disease (IPD); Pneumonia; and Otitis media (ear infection).

Olele said Prevenar 13 is generally well tolerated and has a demonstrated safety profile and the first and only PCV approved from infancy through adulthood.

She said that Pfizer pulled down the cost of the vaccine specifically to expand access to disaster prone challenges including about six million persons in the Internally Displaced Persons (IDP) camps in northern Nigeria.

A paediatrician at the College of Medicine at the University of Ibadan, Oyo State, Dr. Adejumoke I. Ayede, said Prevenar 13 is one of the conjugate vaccines that cover the stereotype that can cause pneumonia and is the best that can give the wider spectrum. Ayede said evidences upon evidence, research upon every research has shown initial in Africa, North America, Asia Europe that once you bring PCV 13 it reduces the mortality.

Ayede said: “It reduces morbidity and that is why the medical profession is really excited that this has come not only is it effective its also cost effective and there is also what is called the head effect that if you treat a child or a sick person in the family, you prevent a diseases. To keep everybody safe so it is a matter of not just vaccinating some people and the whole community is protected.

Meanwhile, the GPEI said the breakthrough opens up the possibility of not needing to keep stock of wild poliovirus to manufacture polio vaccines. A virus-free production process would reduce the risks presented by keeping stocks of the virus, reducing the need for strict biosafety requirements and bringing down the cost of vaccine production.

The GPEI said such an approach could significantly increase countries’ capacity to produce their own national supply of the vaccine, including in developing country settings, due to the strict guidelines for any facility with stocks of live poliovirus.